Fragile Sites of 'Valencia' Sweet Orange (Citrus sinensis) Chromosomes Are Related with Active 45s rDNA.

PubMed

Lan, Hong; Chen, Chun-Li; Miao, Yin; Yu, Chang-Xiu; Guo, Wen-Wu; Xu, Qiang; Deng, Xiu-Xin

2016-01-01

Citrus sinensis chromosomes present a morphological differentiation of bands after staining by the fluorochromes CMA and DAPI, but there is still little information on its chromosomal characteristics. In this study, the chromosomes in 'Valencia' C. sinensis were analyzed by fluorescence in situ hybridization (FISH) using telomere DNA and the 45S rDNA gene as probes combining CMA/DAPI staining, which showed that there were two fragile sites in sweet orange chromosomes co-localizing at distended 45S rDNA regions, one proximally locating on B-type chromosome and the other subterminally locating on D-type chromosome. While the chromosomal CMA banding and 45S rDNA FISH mapping in the doubled haploid line of 'Valencia' C. sinensis indicated six 45S rDNA regions, four were identified as fragile sites as doubled comparing its parental line, which confirmed the cytological heterozygosity and chromosomal heteromorphisms in sweet orange. Furthermore, Ag-NOR identified two distended 45S rDNA regions to be active nucleolar organizing regions (NORs) in diploid 'Valencia' C. sinensis. The occurrence of quadrivalent in meiosis of pollen mother cells (PMCs) in 'Valencia' sweet orange further confirmed it was a chromosomal reciprocal translocation line. We speculated this chromosome translocation was probably related to fragile sites. Our data provide insights into the chromosomal characteristics of the fragile sites in 'Valencia' sweet orange and are expected to facilitate the further investigation of the possible functions of fragile sites.

Pesticide residues in orange fruit from citrus orchards in Nuevo Leon State, Mexico.

PubMed

Suárez-Jacobo, Angela; Alcantar-Rosales, Victor Manuel; Alonso-Segura, Diana; Heras-Ramírez, Maria; Elizarragaz-De La Rosa, Dalau; Lugo-Melchor, Ofelia; Gaspar-Ramirez, Octavio

2017-09-01

Some international organisations established maximum residue limits (MRLs) in food to protect human health. Mexico lacks regulations in this matter, affecting national and international trade from agroindustry. The aim of this study was to diagnose pesticide residues in oranges from Nuevo Leon, México, in citrus orchards. In May 2014, 100 orange fruit samples were taken randomly from orchards and subjected to analysis for 93 pesticides at residual level by GC/QQQ-MS and LCQ-TOF-MS. Results showed the presence of 15 pesticide residues in the samples. The comparison of the residual levels of pesticides found in orange samples among the MRLs allowed by USA, EU and Japanese regulations demonstrated that all samples were below MRLs issued by USA and Japan. Some orange samples were above MRLs issued by the EU. This provides a basis to establish strategies in order to satisfy International Standards to protect human health and encourage Food Safety in Mexico.

Non-phytoseiid Mesostigmata within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants and additional collection records of mites in citrus orchards.

PubMed

Childers, Carl C; Ueckermann, Eduard A

2015-03-01

Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the

Seasonal Abundance and Suppression of Fruit-Piercing Moth Eudocima phalonia (L.) in a Citrus Orchard in Sarawak

PubMed Central

Leong, Stephen Chan Teck; Kueh, Roland Jui Heng

2011-01-01

Seasonal population of the fruit-piercing moths Eudocima spp. was monitored throughout the citrus growing seasons in a citrus orchard and in site adjacent to secondary forest from July 2007 to June 2009. The moth was detected practically throughout the year with activity lowest during the wet months (September-February) when fruits are still available and while highest during the dry months (May-June) which also coincided with the main fruiting season. The effects of an nC24 horticultural mineral oil (HMO) on the citrus fruit damage caused by fruit-piecing moths was also determined. The percent fruit damage was significantly lowest (P≤0.05) in HMO-treated plots (8.4), followed by Dimethoate-treated plots (11.6) and untreated plots (22.5). However, there was no significant difference between HMO and Dimethoate treated plots indicating HMO is effective in reducing percent fruit damage. PMID:22203789

Effects of open-top chambers on Valencia' orange trees. [Citrus sinensis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszyk, D.M.; Takemoto, B.K.; Kats, G.

Open-top field chambers are the most widely used technology for evaluating the impacts of air pollutants on vegetation. This study was conducted to evaluate the long-term effects of chambers on Valencia orange trees (Citrus sinensis (L.) Osbeck). The trees were exposed to ambient ozone (O{sub 3}) for 51 months in large (4.3-m diam. by 2.9-m high) nonfiltered open-top chambers (NF) and in ambient air without chambers (AA). Results suggest that the yield increases for NF compared to AA trees could, in part, be accounted for by decreased flux of O{sub 3} into leaves (based on decreased O{sub 3} exposure andmore » leaf conductance). However, other factors, i.e., increased tree growth, altered leaf C allocation, and lack of wind stress occurring only in chambers, likely contributed to higher NF tree yields.« less

Spatial distribution of parasitism on Phyllocnistis citrella Stainton, 1856 (Lepidoptera: Gracillariidae) in citrus orchards.

PubMed

Jahnke, S M; Redaelli, L R; Diefenbach, L M G; Efrom, C F

2008-11-01

Many species of microhymenopterous parasitoids have been registered on Phyllocnistis citrella, the citrus leafminer. The present study aimed to identify the spatial distribution pattern of the native and introduced parasitoids of P. citrella in two citrus orchards in Montenegro, RS. The new shoots from 24 randomly selected trees in each orchard were inspected at the bottom (0-1.5 m) and top (1.5-2.5 m) stratum and had their position relative to the quadrants (North, South, East and West) registered at every 15 days from July/2002 to June/2003. The leaves with pupae were collected and kept isolated until the emergence of parasitoids or of the leaf miner; so, the sampling was biased towards parasitoids that emerge in the host pupal phase. The horizontal spatial distribution was evaluated testing the fitness of data to the Poisson and negative binomial distributions. In Montenegrina, there was no significant difference in the number of parasitoids and in the mean number of pupae found in the top and bottom strata (chi2 = 0.66; df = 1; P > 0.05) (chi2 = 0.27; df =1; P > 0.05), respectively. In relation to the quadrants, the highest average numbers of the leafminer pupae and of parasitoids were registered at the East quadrant (chi2 = 11.81; df = 3; P < 0.05), (chi2 = 10.36; df = 3; P < 0.05). In the Murcott orchard, a higher number of parasitoids was found at the top stratum (63.5%) (chi2 = 7.24; df =1 P < 0.05), the same occurring with the average number of P. citrella pupae (62.9%) (chi2 = 6.66; df = 1; P < 0.05). The highest number of parasitoids and of miners was registered at the North quadrant (chi2 = 19. 29; df = 3; P < 0.05), (chi2 = 4.39; df = 3; P < 0.05). In both orchards, there was no difference between the numbers of shoots either relative to the strata as well as to the quadrants. As the number of shoots did not varied much relative to the quadrants, it is possible that the higher number of miners and parasitoids in the East and West quadrants would be

Characterization of three terpenoid glycosyltransferase genes in 'Valencia' sweet orange (Citrus sinensis L. Osbeck).

PubMed

Fan, Jing; Chen, Chunxian; Yu, Qibin; Li, Zheng-Guo; Gmitter, Frederick G

2010-10-01

Three putative terpenoid UDP-glycosyltransferase (UGT) genes, designated CsUGT1, CsUGT2, and CsUGT3, were isolated and characterized in 'Valencia' sweet orange (Citrus sinensis L. Osbeck). CsUGT1 consisted of 1493 nucleotides with an open reading frame encoding 492 amino acids, CsUGT2 consisted of 1727 nucleotides encoding 504 amino acids, and CsUGT3 consisted of 1705 nucleotides encoding 468 amino acids. CsUGT3 had a 145 bp intron at 730-874, whereas CsUGT1 and CsUGT2 had none. The three deduced glycosyltransferase proteins had a highly conserved plant secondary product glycosyltransferase motif in the C terminus. Phylogenetic analysis showed that CsUGT1 and CsUGT3 were classified into group L of glycosyltransferase family 1, and CsUGT2 was classified into group D. Through Southern blotting analysis, CsUGT1 was found to have two copies in the sweet orange genome, whereas CsUGT2 and CsUGT3 had at least seven and nine copies, respectively. CsUGT1, CsUGT2, and CsUGT3 were constitutively expressed in leaf, flower, and fruit tissues. The results facilitate further investigation of the function of terpenoid glycosyltransferases in citrus and the biosynthesis of terpenoid glycosides in vitro.

Spatial Genetic Structure of Coffee-Associated Xylella fastidiosa Populations Indicates that Cross Infection Does Not Occur with Sympatric Citrus Orchards.

PubMed

Francisco, Carolina S; Ceresini, Paulo C; Almeida, Rodrigo P P; Coletta-Filho, Helvécio D

2017-04-01

Xylella fastidiosa, an economically important plant-pathogenic bacterium, infects both coffee and citrus trees in Brazil. Although X. fastidiosa in citrus is well studied, knowledge about the population structure of this bacterium infecting coffee remains unknown. Here, we studied the population structure of X. fastidiosa infecting coffee trees in São Paulo State, Brazil, in four regions where citrus is also widely cultivated. Genotyping of over 500 isolates from coffee plants using 14 genomic microsatellite markers indicated that populations were largely geographically isolated, as previously found with populations of X. fastidiosa infecting citrus. These results were supported by a clustering analysis, which indicated three major genetic groups among the four sampled regions. Overall, approximately 38% of isolates showed significant membership coefficients not related to their original geographical populations (i.e., migrants), characterizing a significant degree of genotype flow among populations. To determine whether admixture occurred between isolates infecting citrus and coffee plants, one site with citrus and coffee orchards adjacent to each other was selected; over 100 isolates were typed from each host plant. No signal of natural admixture between citrus- and coffee-infecting isolates was found; artificial cross-infection assays with representative isolates also yielded no successful cross infection. A comparison determined that X. fastidiosa populations from coffee have higher genetic diversity and allelic richness compared with citrus. The results showed that coffee and citrus X. fastidiosa populations are effectively isolated from each other and, although coffee populations are spatially structured, migration has an important role in shaping diversity.

Soil organic matter on citrus plantation in Eastern Spain

NASA Astrophysics Data System (ADS)

Cerdà, Artemi; Pereira, Paulo; Novara, Agata; Prosdocimi, Massimo

2015-04-01

Citrus plantations in Eastern Spain are the main crop and Valencia region is the largest world exporter. The traditional plantation are located on flood irrigated areas and the new plantation are located on slopes were drip irrigation is the source of the wetting. It has been demonstrate that the citrus plantations contribute to high erosion rates on slopes (Cerdà et al., 2009b) as it is usual on agriculture land (Cerdà et al., 2009a), but when organic farming is present the soil erosion is much lower (Cerdà and Jurgensen, 2008; Cerdà et al., 2009; Cerdà and Jurgensen, 2011). This is a worldwide phenomenon (Wu et al., 2007; Wu et al., 2011; Xu et al., 2010; Xu et al., 2012a; Xu et al., 2012b), which are a key factor of the high erosion rates in rural areas (García Orenes et al., 2009: García Orenes et al., 20010; García Orenes et al., 2012; Haregewyn et al., 2013; Zhao et al., 2013). The key factor of the contrasted response of soils to the rain in citrus is the organic matter cover. This is why the Soil Erosion and Degradation Research Team developed a survey to determine the soil erosion rates on citrus orchards under different managements. A hundred of samples were collected in a citrus plantation on slope under conventional management (Chemical management), one on organic farming, one on traditional flood irrigated organic farming and one on traditional chemical flooding farm. The organic farming soils were treated with 10000 Kg ha-1 of manure yearly. The results show that the mean soil organic matter content was 1.24 %, 3.54%, 5,43% and 2.1% respectively, which show a clear impact of organic farming in the recovery of the soil organic matter. meanwhile the on the slopes and the flood-irrigated soils are Acknowledgements The research projects GL2008-02879/BTE, LEDDRA 243857 and PREVENTING AND REMEDIATING DEGRADATION OF SOILS IN EUROPE THROUGH LAND CARE (RECARE)FP7- ENV-2013- supported this research. References Cerdà, A., Flanagan, D.C., le Bissonnais

Changes in the levels of polymethoxyflavones and flavanones as part of the defense mechanism of Citrus sinensis (cv. Valencia Late) fruits against Phytophthora citrophthora.

PubMed

del Río, J A; Gómez, P; Baidez, A G; Arcas, M C; Botía, J M; Ortuño, A

2004-04-07

Phytophthora citrophthora causes serious losses in Citrus fruits through brown rot lesion. The effect of infection with P. citrophthora on Citrus sinensis (cv. Valencia Late) fruits was studied, with particular reference to the levels of the flavanones hesperidin and isonaringin and the polymethoxyflavones sinensetin, nobiletin, tangeretin, and heptamethoxyflavone, because flavonoids are most probably involved as natural defense or resistance mechanisms in this genus. Changes in the levels of these flavonoids were detected after infection. The hesperidin and isonaringin contents fell by 13 and 67%, respectively, whereas the contents of their corresponding aglycons, hesperetin and naringenin, increased, suggesting the hydrolyzing effect of this fungus on the glycosylated flavanones. The heptamethoxyflavone, nobiletin, sinensetin, and tangeretin levels increased by 48, 28, 26, and 24%, respectively. The in vitro study revealed that these compounds acted as antifungal agents, the most active being the aglycons (naringenin and hesperetin), followed by the polymethoxyflavones and flavanone glycosides. The participation of these flavonoids in the defense mechanism of this Citrus species is discussed.

Consideration for alternative outlet for new citrus hybrids

USDA-ARS?s Scientific Manuscript database

Citrus sinensis (sweet orange, ex. Hamlin, Midsweet, Valencia) is the source of “orange juice” and juice must contain no less than 90% C. sinensis to be marketed as such. Juice produced from Citrus reticulata (mandarins) and C. reticulata hybrids (Orlando, Murcott, Fallglo, Sunburst, Minneola) can b...

The effect of pre spring spray to reduce of citrus important pests.

PubMed

Hashemi, B; Damavandian, M R; Shoushtaril, R Vafaei; Tafaghodynia, B

2008-10-01

The importance of pre spring spray against citrus aphids, Pulvinaria aurantii Cockerell and Panonychus citri McGregor that are the most important pest of citrus during spring was tested. In this research, 150 trees ten years old sweet orange (Thomson navel on Citrus aurantium (root stocks)) in a citrus orchard approximately three hectares sampled. The experiment was laid out in a totally randomized (one-way) design replicated five times. According to the results, the pre spring spray do not effect on population density of citrus aphids and P. aurantii during March, April, May and June. However, the P. citri population decreased. Therefore, it seems the pre spring spray in citrus orchards is not necessary, but if P. citri is observed, the pre spring spray should be recommended.

Larvicidal Activity of Citrus Limonoids against Aedes albopictus Larvae.

PubMed

Bilal, Hazrat; Akram, Waseem; Ali-Hassan, Soaib

2012-12-01

Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticides therefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppress mosquito larval population. WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used. Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis) was the best in terms of LC(50) (297 ppm), % mortality (97%) and LT(50) (18.49 hours) then freutrall early (Citrus reticulate) with LC(50) (377.4 ppm), % mortality (88%) and LT(50) (31 hours), While nomilin gave lowest LC(50) (121.04 ppm) than limonin (382.22 ppm) after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml) than freutrall early (5.29 μg/ml and 3.89 μg/ml) respectively. Valencia late showed best results in term of LC(50), LT(50) and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required.

Larvicidal Activity of Citrus Limonoids against Aedes albopictus Larvae

PubMed Central

Bilal, Hazrat; Akram, Waseem; Ali-Hassan, Soaib

2012-01-01

Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticides therefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppress mosquito larval population. Methods: WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used. Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis) was the best in terms of LC50 (297 ppm), % mortality (97%) and LT50 (18.49 hours) then freutrall early (Citrus reticulate) with LC50 (377.4 ppm), % mortality (88%) and LT50 (31 hours), While nomilin gave lowest LC50 (121.04 ppm) than limonin (382.22 ppm) after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml) than freutrall early (5.29 μg/ml and 3.89 μg/ml) respectively. Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required. PMID:23378967

Spatial relationships between entomopathogenic nematodes and nematophagous fungi in Florida citrus orchards.

PubMed

Pathak, Ekta; Campos-Herrera, Raquel; El-Borai, Fahiem E; Duncan, Larry W

2017-03-01

Relationships between entomopathogenic nematodes (EPNs), nematophagous fungi (NF) and soil physical and chemical properties were studied in a survey of 53 citrus orchards in central ridge and flatwoods ecoregions of Florida. Seven species of NF associated with nematodes were quantified directly using a real time qPCR assay. All nematophagous fungi studied except Arthrobotrys musiformis and Hirsutella rhossiliensis were frequently detected (24-56%) in both regions. Paecilomyces lilacinus and Gamsylella gephyropagumwere encountered more frequently in the flatwoods (P=0.03) and on the ridge (P=0.02), respectively. Redundancy analysis revealed seven abiotic and biotic factors as significantly related to the NF occurrence. Multiple regression of fungi on these variables explained 78%, 66%, 48%, 36%, 23% and 4% of the variation in Catenaria sp., A. musiformis, A. dactyloides, P. lilacinus, A. oligospora and G. gepharopagum, respectively. When the data from citrus were pooled with those reported previously from natural areas and subjected to principle component analysis, the first two principle components explained 43% of the variation in NF communities. The surveys (citrus vs natural areas) were discriminated by PC2 (P<0.001) and the ecoregion by PC1 (P<0.002), and all but one NF species were related (P<0.01) to one or both components. NF communities tended to have more species and greater diversity in the flatwoods, where EPN richness and diversity were the least. However, the strength of associations between individual EPN and NF species as measured by SADIE reflected the associations between each species and ground water depth, suggesting that ecoregion preferences affected the species associations. Within each ecoregion, significant relationships between the individual NF and EPN species measured by stepwise regression tended to be positive. The results did not support the hypothesis that NF modulate the spatial patterns of EPN species between or within these two

Effect of long-term different fertilization on bacterial community structures and diversity in citrus orchard soil of volcanic ash.

PubMed

Joa, Jae Ho; Weon, Hang Yeon; Hyun, Hae Nam; Jeun, Young Chull; Koh, Sang Wook

2014-12-01

This study was conducted to assess bacterial species richness, diversity and community distribution according to different fertilization regimes for 16 years in citrus orchard soil of volcanic ash. Soil samples were collected and analyzed from Compost (cattle manure, 2,000 kg/10a), 1/2 NPK+compost (14-20-14+2,000 kg/10a), NPK+compost (28-40-28+2,000 kg/10a), NPK (28-40-28 kg/10a), 3 NPK (84-120-84 kg/10a), and Control (no fertilization) plot which have been managed in the same manners with compost and different amount of chemical fertilization. The range of pyrosequencing reads and OTUs were 4,687-7,330 and 1,790-3,695, respectively. Species richness estimates such as Ace, Chao1, and Shannon index were higher in 1/2 NPK+compost than other treatments, which were 15,202, 9,112, 7.7, respectively. Dominant bacterial groups at level of phylum were Proteobacteria, Acidobacteria, and Actinobacteria. Those were occupied at 70.9% in 1/2 NPK+compost. Dominant bacterial groups at level of genus were Pseudolabrys, Bradyrhizobium, and Acidobacteria. Those were distributed at 14.4% of a total of bacteria in Compost. Soil pH displayed significantly closely related to bacterial species richness estimates such as Ace, Chao1 (p<0.05) and Shannon index (p<0.01). However, it showed the negative correlation with exchangeable aluminum contents (p<0.05). In conclusion, diversity of bacterial community in citrus orchard soil was affected by fertilization management, soil pH changes and characteristics of volcanic ash.

Metabolomic comparative analysis of the phloem sap of curry leaf tree (Bergera koenegii), orange jasmine (Murraya paniculata), and Valencia sweet orange (Citrus sinensis) supports their differential responses to Huanglongbing

PubMed Central

Killiny, Nabil

2016-01-01

ABSTRACT Orange jasmine, Murraya paniculata and curry leaf tree, Bergera koenegii are alternative hosts for Diaphorina citri, the vector of Candidatus Liberibacter asiaticus (CLas), the pathogen of huanglongbing (HLB) in citrus. D. citri feeds on the phloem sap where CLas grows. It has been shown that orange jasmine was a better host than curry leaf tree to D. citri. In addition, CLas can infect orange jasmine but not curry leaf tree. Here, we compared the phloem sap composition of these 2 plants to the main host, Valencia sweet orange, Citrus sinensis. Phloem sap was analyzed by gas chromatography-mass spectrometry after trimethylsilyl derivatization. Orange jasmine was the highest in proteinogenic, non-proteinogenic amino acids, organic acids, as well as total metabolites. Valencia was the highest in mono- and disaccharides, and sugar alcohols. Curry leaf tree was the lowest in most of the metabolites as well as total metabolites. Interestingly, malic acid was high in Valencia and orange jasmine but was not detected in the curry leaf. On the other hand, tartaric acid which can prevent the formation of malic acid in Krebs cycle was high in curry leaf. The nutrient inadequacy of the phloem sap in curry leaf tree, especially the amino acids could be the reason behind the longer life cycle and the low survival of D. citri and the limitation of CLas growth on this host. Information obtained from this study may help in cultivation of CLas and development of artificial diet for rearing of D. citri. PMID:27763819

Metabolomic comparative analysis of the phloem sap of curry leaf tree (Bergera koenegii), orange jasmine (Murraya paniculata), and Valencia sweet orange (Citrus sinensis) supports their differential responses to Huanglongbing.

PubMed

Killiny, Nabil

2016-11-01

Orange jasmine, Murraya paniculata and curry leaf tree, Bergera koenegii are alternative hosts for Diaphorina citri, the vector of Candidatus Liberibacter asiaticus (CLas), the pathogen of huanglongbing (HLB) in citrus. D. citri feeds on the phloem sap where CLas grows. It has been shown that orange jasmine was a better host than curry leaf tree to D. citri. In addition, CLas can infect orange jasmine but not curry leaf tree. Here, we compared the phloem sap composition of these 2 plants to the main host, Valencia sweet orange, Citrus sinensis. Phloem sap was analyzed by gas chromatography-mass spectrometry after trimethylsilyl derivatization. Orange jasmine was the highest in proteinogenic, non-proteinogenic amino acids, organic acids, as well as total metabolites. Valencia was the highest in mono- and disaccharides, and sugar alcohols. Curry leaf tree was the lowest in most of the metabolites as well as total metabolites. Interestingly, malic acid was high in Valencia and orange jasmine but was not detected in the curry leaf. On the other hand, tartaric acid which can prevent the formation of malic acid in Krebs cycle was high in curry leaf. The nutrient inadequacy of the phloem sap in curry leaf tree, especially the amino acids could be the reason behind the longer life cycle and the low survival of D. citri and the limitation of CLas growth on this host. Information obtained from this study may help in cultivation of CLas and development of artificial diet for rearing of D. citri.

Nitrate fluxes to groundwater under citrus orchards in a Mediterranean climate: Observations, calibrated models, simulations and agro-hydrological conclusions

NASA Astrophysics Data System (ADS)

Kurtzman, Daniel; Shapira, Roi H.; Bar-Tal, Asher; Fine, Pinchas; Russo, David

2013-08-01

Nitrate contamination of groundwater under land used for intensive-agriculture is probably the most worrisome agro-hydrological sustainability problem worldwide. Vadose-zone samples from 0 to 9 m depth under citrus orchards overlying an unconfined aquifer were analyzed for variables controlling water flow and the fate and transport of nitrogen fertilizers. Steady-state estimates of water and NO3-N fluxes to groundwater were found to vary spatially in the ranges of 90-330 mm yr- 1 and 50-220 kg ha- 1 yr- 1, respectively. Calibration of transient models to two selected vadose-zone profiles required limiting the concentration of NO3-N in the solution that is taken up by the roots to 30 mg L- 1. Results of an independent lysimeter experiment showed a similar nitrogen-uptake regime. Simulations of past conditions revealed a significant correlation between NO3-N flux to groundwater and the previous year's precipitation. Simulations of different nitrogen-application rates showed that using half of the nitrogen fertilizer added to the irrigation water by farmers would reduce average NO3-N flux to groundwater by 70%, decrease root nitrogen uptake by 20% and reduce the average pore water NO3-N concentration in the deep vadose zone to below the Israeli drinking water standard; hence this rate of nitrogen application was found to be agro-hydrologically sustainable. Beyond the investigation of nitrate fluxes to groundwater under citrus orchards and the interesting case-study aspects, this work demonstrates a methodology that enables skillful decisions concerning joint sustainability of both the water resource and agricultural production in a common environmental setting.

Production, soil erosion and economic failure in new citrus plantations in Eastern Spain

NASA Astrophysics Data System (ADS)

Giménez Morera, Antonio; Carles membrado, Joan; Cerdà, Artemi; Ángel González Peñaloza, Félix

2013-04-01

investment to develop the new plantations, an income lower than the expenses, the removal of terraces, drainage and irrigation ditches and the high erosion rates show a Desertification process triggered by the commercial agriculture of citrus. Acknowledgements The research projects GL2008-02879/BTE and LEDDRA 243857 supported this research. References Bono, E. 2010. Naranja y desarrollo. La base agrícola exportadora de la economía del País Valenciano y el modelo de crecimiento hacea afuera. PUV, Valencia, 203 pp. Cerdà, A. 2001. Erosión hídrica del suelo en el Territorio Valenciano. El estado de la cuestión a través de la revisión bibliográfica. Geoforma Ediciones, Logroño, 79 pp. Cerdá, A. 2007. Soil water erosion on road embankments in Eastern Spain. Science of the Total Environments 378, 151-155. Cerdà, A., Morera, A.G., Bodí, M.B. 2009. Soil and water losses from new citrus orchards growing on sloped soils in the western Mediterranean basin. Earth Surface Processes and Landforms, 34 (13), 1822-1830. García-Orenes, F., Cerdà, A., Mataix-Solera, J., Guerrero, C., Bodí, M.B., Arcenegui, V., Zornoza, R. & Sempere, J.G. 2009. Effects of agricultural management on surface soil properties and soil-water losses in eastern Spain. Soil and Tillage Research, doi:10.1016/j.still.2009.06.002 González-Peñaloza, F.A., Cerdà, Zavala, L.M., Jordán, A. 2012. Do conservative agriculture practices increase soil water repellency? A case study in citrus-cropped soils. Soil & Tillage Research 124, 233 - 239. Liu, Y., Tao, Y., Wan, K.Y., Zhang, G.S., Liu, D.B., Xiong, G.Y., Chen, F. 2012. Runoff and nutrient losses in citrus orchards on sloping land subjected to different surface mulching practices in the Danjiangkou Reservoir area of China. Agricultural Water Management, 110, 34-40. Piqueras, J. 1999. El espacio Geográfico valenciano. Una síntesis geográfica. Valencia, 356 pp. Piqueras, J. 2012. Geografía del Territorio Valenciano. Departament de Geografia, Universitat

Estimation of the number of aphids carrying Citrus tristeza virus that visit adult citrus trees.

PubMed

Marroquín, Carlos; Olmos, Antonio; Teresa Gorris, María; Bertolini, Edson; Carmen Martínez, M; Carbonell, Emilio A; Hermoso de Mendoza, Alfonso; Cambra, Mariano

2004-03-01

Aphid species were counted on citrus trees in orchards in Valencia, Spain, in the spring and autumn of 1997, 1998 and 1999. Moericke yellow water traps, the 'sticky shoot' method and counts of established colonies were used in extensive surveys in which 29,502 aphids were recorded and identified. Aphis spiraecola and Aphis gossypii were the most abundant aphid species. The numbers of aphid species landing on mature trees of grapefruit, sweet orange, lemon and clementine and satsuma mandarins, were estimated by counting the numbers of young shoots/tree and aphids trapped on sticky shoots. The proportions of the different aphid species captured were: A. gossypii (53%), A. spiraecola (32%), Toxoptera aurantii (11%), Myzus persicae (1%), Aphis craccivora (1%) and other species (2%). Clementine was the most visited species with 266,700 aphids landing/tree in spring 2000, followed by lemon (147,000), sweet orange (129,150), grapefruit (103,200), and satsuma (92,400). The numbers and relative percentages of aphids carrying Citrus tristeza virus (CTV) were assessed by nested RT-PCR in single closed tubes and analysed by extraction of RNA-CTV targets from trapped aphids. An average of 37,190 CTV-carrying aphids visited each tree in spring 2000 (29 per shoot). The percentage detection of viral RNA in the aphid species that landed were 27% for A. gossypii, 23% for A. spiraecola and 19% for T. aurantii. This high incidence of aphids carrying CTV is consistent with the high prevalence and rapid spread of CTV in sweet orange, clementine, and satsuma mandarins in recent years in the region. The infection rate was proportional to the number of aphids landing/tree.

Monitoring Citrus Soil Moisture and Nutrients Using an IoT Based System.

PubMed

Zhang, Xueyan; Zhang, Jianwu; Li, Lin; Zhang, Yuzhu; Yang, Guocai

2017-02-23

Chongqing mountain citrus orchard is one of the main origins of Chinese citrus. Its planting terrain is complex and soil parent material is diverse. Currently, the citrus fertilization, irrigation and other management processes still have great blindness. They usually use the same pattern and the same formula rather than considering the orchard terrain features, soil differences, species characteristics and the state of tree growth. With the help of the ZigBee technology, artificial intelligence and decision support technology, this paper has developed the research on the application technology of agricultural Internet of Things for real-time monitoring of citrus soil moisture and nutrients as well as the research on the integration of fertilization and irrigation decision support system. Some achievements were obtained including single-point multi-layer citrus soil temperature and humidity detection wireless sensor nodes and citrus precision fertilization and irrigation management decision support system. They were applied in citrus base in the Three Gorges Reservoir Area. The results showed that the system could help the grower to scientifically fertilize or irrigate, improve the precision operation level of citrus production, reduce the labor cost and reduce the pollution caused by chemical fertilizer.

GC-MS analysis of headspace and liquid extracts for metabolomic differentiation of citrus Huanglongbing and zinc deficiency in leaves of 'Valencia' sweet orange from commercial groves.

PubMed

Cevallos-Cevallos, Juan Manuel; García-Torres, Rosalía; Etxeberria, Edgardo; Reyes-De-Corcuera, José Ignacio

2011-01-01

Citrus Huanglongbing (HLB) is considered the most destructive citrus disease worldwide. Symptoms-based detection of HLB is difficult due to similarities with zinc deficiency. To find metabolic differences between leaves from HLB-infected, zinc-deficient, and healthy 'Valencia' orange trees by using GC-MS based metabolomics. Analysis based on GC-MS methods for untargeted metabolite analysis of citrus leaves was developed and optimized. Sample extracts from healthy, zinc deficient, or HLB-infected sweet orange leaves were submitted to headspace solid phase micro-extraction (SPME) and derivatization treatments prior to GC-MS analysis. Principal components analysis achieved correct classification of all the derivatized liquid extracts. Analysis of variance revealed 6 possible biomarkers for HLB, of which 5 were identified as proline, β-elemene, (-)trans- caryophyllene, and α-humulene. Significant (P < 0.05) differences in oxo-butanedioic acid, arabitol, and neo-inositol were exclusively detected in samples from plants with zinc deficiency. Levels of isocaryophyllen, α-selinene, β-selinene, and fructose were significantly (P < 0.05) different in healthy leaves only. Results suggest the potential of using identified HLB biomarkers for rapid differentiation of HLB from zinc deficiency. Copyright © 2010 John Wiley & Sons, Ltd.

7 CFR 457.121 - Arizona-California citrus crop insurance provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... & Sweet oranges 38 Container #58 Lemons 40 Container #59 Grapefruit 32 Container #63 Tangerines (including... California lemons; (ii) November 20 for Valencia oranges; and (iii) July 31 for all other citrus crops. (b...

7 CFR 457.121 - Arizona-California citrus crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... & Sweet oranges 38 Container #58 Lemons 40 Container #59 Grapefruit 32 Container #63 Tangerines (including... California lemons; (ii) November 20 for Valencia oranges; and (iii) July 31 for all other citrus crops. (b...

7 CFR 457.121 - Arizona-California citrus crop insurance provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... & Sweet oranges 38 Container #58 Lemons 40 Container #59 Grapefruit 32 Container #63 Tangerines (including... California lemons; (ii) November 20 for Valencia oranges; and (iii) July 31 for all other citrus crops. (b...

Cryopreservation of Citrus seeds via dehydration and direct immersion in liquid nitrogen

USDA-ARS?s Scientific Manuscript database

Citrus germplasm is conventionally conserved in clonal orchards and greenhouses, where it is subjected to potential losses due to pests, diseases and climatic hazards. In recent years, many studies reported preservation of germplasm in the genus Citrus. As a result, effective freezing protocols have...

A beta-galactosidase gene is expressed during mature fruit abscission of 'Valencia' orange (Citrus sinensis).

PubMed

Wu, Zhencai; Burns, Jacqueline K

2004-07-01

beta-galactosidases have been detected in a wide range of plants and are characterized by their ability to hydrolyse terminal non-reducing beta-D-galactosyl residues from beta-D-galactosides. These enzymes have been detected in a wide range of plant organs and tissues. In a search for differentially expressed genes during the abscission process in citrus, sequences encoding beta-galactosidase were identified. Three cDNA fragments of a beta-galactosidase gene were isolated from a cDNA subtraction library constructed from mature fruit abscission zones 48 h after the application of a mature fruit-specific abscission agent, 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMN-pyrazole). Based on sequence information derived from these fragments, a full-length cDNA of 2847 nucleotides (GenBank accession number AY029198) encoding beta-galactosidase was isolated from mature fruit abscission zones by 5'- and 3'-RACE approaches. The beta-galactosidase cDNA encoded a protein of 737 amino acid residues with a calculated molecular weight of 82 kDa. The deduced protein was highly homologous to plant beta-galactosidases expressed in fruit ripening. Southern blot analysis demonstrated that at least two closely related beta-galactosidase genes were present in 'Valencia' orange. Temporal expression patterns in mature fruit abscission zones indicated beta-galactosidase mRNA was detected 48 h after treatment of CMN-pyrazole and ethephon in mature fruit abscission zones. beta-galactosidase transcripts were detected in leaf abscission zones only after ethephon application. The citrus beta-galactosidase was expressed in stamens and petals of fully opened flowers and young fruitlets. The results suggest that this beta-galactosidase may play a role during abscission as well as early growth and development processes in flowers and fruitlets.

Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

NASA Astrophysics Data System (ADS)

Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

2013-04-01

Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip

The use of pruned chipped branches to increase the soil infiltration capacity and reduce the soil losses on citrus orchards in Eastern Spain

NASA Astrophysics Data System (ADS)

González-Pelayo, Óscar; Llovet, Joan; Giménez-Morera, Antonio; Jordán, Antonio; Pereira, Paulo; Novara, Agata; García-Orenes, Fuensanta; Cerdà, Artemi

2015-04-01

Soil water erosion is causing problems on the agriculture land of the world. The high erosion rates registered in the agriculture land are due to the lack of a vegetation cover that protects the soil. High erosion rates in agriculture lands are found in Africa, Europe, Asia, and any other continent. Soil erosion on citrus orchards has been researched recently and shown huge erosion rates in the Mediterranean and in China. All this research findings allow us to confirm that the soil erosion rates on citrus orchards are not sustainable and strategies to control the soil erosion should be applied. The increasing erosion rates are due to the bare soils, but also are due to the soil structure degradation and soil organic matter exhaustion. Some authors applied cover on crops to avoid the raindrop impact and the surfaces wash but there is a need to develop new strategies to reduce soil losses and keep sustainable the citrus productions. The agriculture production also results in a large amount of residues than can be a resource to improve the soil cover. This has been done in road embankments, in forest land affected by wildfires and on afforestation. As a consequence of the mechanization of the agriculture, and the reduction of the draft animals (mainly horses, mules, donkeys and oxen), the straw and the pruned branches are being a residue instead of a resource in many developed countries. Straw was used as a forage and the pruned branches as a source of heat and energy but both can be used as a mulch to control the soil erosion. The pruned branches can contribute with a valuable source of nutrients and a good soil protection. The leaves of the trees, and some parts of the plants, once harvest can contribute to reduce the soil losses. Our goal is to test if a residue such as the chipped pruned branches can be transformed as a resource that will help to control the soil erosion rates. Straw has been seen as a very efficient to reduce the water losses in agriculture land

Accumulation of Carotenoids and Expression of Carotenoid Biosynthetic Genes during Maturation in Citrus Fruit1

PubMed Central

Kato, Masaya; Ikoma, Yoshinori; Matsumoto, Hikaru; Sugiura, Minoru; Hyodo, Hiroshi; Yano, Masamichi

2004-01-01

The relationship between carotenoid accumulation and the expression of carotenoid biosynthetic genes during fruit maturation was investigated in three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). We cloned the cDNAs for phytoene synthase (CitPSY), phytoene desaturase (CitPDS), ζ-carotene (car) desaturase (CitZDS), carotenoid isomerase (CitCRTISO), lycopene β-cyclase (CitLCYb), β-ring hydroxylase (CitHYb), zeaxanthin (zea) epoxidase (CitZEP), and lycopene ε-cyclase (CitLCYe) from Satsuma mandarin, which shared high identities in nucleotide sequences with Valencia orange, Lisbon lemon, and other plant species. With the transition of peel color from green to orange, the change from β,ε-carotenoid (α-car and lutein) accumulation to β,β-carotenoid (β-car, β-cryptoxanthin, zea, and violaxanthin) accumulation was observed in the flavedos of Satsuma mandarin and Valencia orange, accompanying the disappearance of CitLCYe transcripts and the increase in CitLCYb transcripts. Even in green fruit, high levels of β,ε-carotenoids and CitLCYe transcripts were not observed in the juice sacs. As fruit maturation progressed in Satsuma mandarin and Valencia orange, a simultaneous increase in the expression of genes (CitPSY, CitPDS, CitZDS, CitLCYb, CitHYb, and CitZEP) led to massive β,β-xanthophyll (β-cryptoxanthin, zea, and violaxanthin) accumulation in both the flavedo and juice sacs. The gene expression of CitCRTISO was kept low or decreased in the flavedo during massive β,β-xanthophyll accumulation. In the flavedo of Lisbon lemon and Satsuma mandarin, massive accumulation of phytoene was observed with a decrease in the transcript level for CitPDS. Thus, the carotenoid accumulation during citrus fruit maturation was highly regulated by the coordination of the expression among carotenoid biosynthetic genes. In this paper, the mechanism leading to diversity in �

Contextual view showing northeastern eucalyptus windbreak and portion of citrus ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Contextual view showing northeastern eucalyptus windbreak and portion of citrus orchard. Camera facing 118" east-southeast. - Goerlitz House, 9893 Highland Avenue, Rancho Cucamonga, San Bernardino County, CA

Novel development of a lateral flow immunoassay for rapid field detection of citrus tristeza virus

USDA-ARS?s Scientific Manuscript database

Maintenance of virus-free citrus in nurseries and orchards is essential to control spread of aphid-borne Citrus tristeza virus (CTV) in California. A lateral flow assay (LFA) test strip with a polyclonal antiserum made from virus particles produced in Nicotiana benthamiana plants inoculated with an ...

Candidatus Liberibacter asiaticus titers in citrus cultivars in the field and in Asian citrus psyllid (ACP) inoculated greenhouse trees

USDA-ARS?s Scientific Manuscript database

A survey of seven citrus cultivars (C. sinensis, C. paradisi, ‘Temple’ tangor, ‘Minneola’ and ‘Orlando’ tangelos and, ‘Fallglo’ and ‘Sunburst’ mandarin hybrids) growing in commercial orchards in Florida revealed a correlation between visual ratings of HLB incidence and severity and CLas titer (Stove...

Effects of oxamyl on the citrus nematode, Tylenchulus semipenetrans, and on infection of sweet orange.

PubMed

Baines, R C; Small, R H

1976-04-01

Foliar sprays of 4 microg/ml oxamyl on sweet orange trees in a greenhouse slightly depressed the number of Tylenchulus semipenetrans larvae obtained from roots and soil, but similar treatments were not effective in two orchards. Soil drench treatments decreased the number of citrus nematode larvae obtained from roots or soil of citrus plants grown itt a greenhouse and in orchards. Exposure to 5-10 microg/ml of oxamyl in water was lethal to only a few second-stage larvae treated 10 days, and many second-stage larvae in 2.0 microg/ml oxamyl recovered motility when transferred to fresh water. Aqueous solutions of 50 and 100 microg/ml of oxamyl were toxic to citrus nematode larvae. Additional observations indicate that oxamyl interfered with hatch of citrus nematode larvae and was nematistatic and/or protected sweet orange roots from infection. Oxamyl degraded at different rates in two soils. The number of citrus nematode larvae that infected and developed on sweet orange roots was increased by an undetermined product of the degradation of oxamyl in soil, water, and possibly within plants. This product apparently was translocated in roots.

Temporal Occurrence and Niche Preferences of Phytophthora spp. Causing Brown Rot of Citrus in the Central Valley of California.

PubMed

Hao, Wei; Miles, Timothy D; Martin, Frank N; Browne, Gregory T; Förster, Helga; Adaskaveg, James E

2018-03-01

Brown rot of citrus fruit is caused by several species of Phytophthora and is currently of serious concern for the California citrus industry. Two species, Phytophthora syringae and P. hibernalis, are quarantine pathogens in China, a major export market for California citrus. To maintain trade and estimate the risk of exporting a quarantine pathogen, the distribution and frequency of Phytophthora spp. causing brown rot of orange in major growing areas of California was investigated. Symptomatic fruit were collected from navel (winter to late spring) and Valencia (late spring to summer) orange orchards from 2013 to 2015. Species identification of isolates was based on morphological characteristics, random amplified polymorphic DNA banding patterns, and sequencing of the internal transcribed spacer and the partial cox2/spacer/cox1 regions from axenic cultures, or directly on DNA from fruit tissue using a multiplex TaqMan quantitative polymerase chain reaction assay. In winter samplings, the incidence of P. syringae based on the number of fruit with Phytophthora spp. detection ranged from 73.6 to 96.1% for the two counties surveyed. The remaining isolates were identified as P. citrophthora. In late spring or summer, only P. citrophthora was recovered. P. hibernalis and P. nicotianae were not detected in any fruit with brown rot symptoms. These results indicate that P. syringae is currently an important brown rot pathogen of citrus fruit in California during the cooler seasons of the year. In winter 2016 and 2017, P. syringae was recovered by pear baiting at a high incidence from leaf litter and from a small number of rhizosphere soil or root samples but not from living leaves on the tree. In contrast, P. citrophthora was rarely found in leaf litter but was commonly detected in the rhizosphere. Thus, leaf litter is a major inoculum source for P. syringae and this species occupies a distinct ecological niche.

Effect of blue LED light intensity on carotenoid accumulation in citrus juice sacs.

PubMed

Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

2015-09-01

In the present study, the effects of blue LED light intensity on carotenoid accumulation and expression of genes related to carotenoid biosynthesis were investigated in the juice sacs of Satsuma mandarin (Citrus unshiu Marc.) and Valencia orange (Citrus sinensis Osbeck) in vitro. The results showed that 100 μmol m(-2)s(-1) blue LED light (100B) was effective for increasing carotenoid content, especially β-cryptoxanthin, in Satsuma mandarin after cultured in vitro for four weeks. In Valencia orange, in contrast, 50 μmol m(-2)s(-1) blue LED light (50B) treatment was effective for inducing carotenoid accumulation through increasing the contents of two major carotenoids, all-trans-violaxanthin and 9-cis-violaxanthin. In addition, gene expression results showed that the simultaneous increases in the expression of genes (CitPSY, CitPDS, CitZDS, CitLCYb2, and CitHYb) involved in producing β,β-xanthophylls were well consistent with the accumulation of β-cryptoxanthin in Satsuma mandarin under 100B, and violaxanthin in Valencia orange under 50B. The results presented herein contribute to further elucidating the regulatory mechanism of carotenoid accumulation by blue LED light. Copyright © 2015 Elsevier GmbH. All rights reserved.

Citrus and Prunuscopia-like retrotransposons.

PubMed

Asíns, M J; Monforte, A J; Mestre, P F; Carbonell, E A

1999-08-01

Many of the world's most important citrus cultivars ("Washington Navel", satsumas, clementines) have arisen through somatic mutation. This phenomenon occurs fairly often in the various species and varieties of the genus.The presence of copia-like retrotransposons has been investigated in fruit trees, especially citrus, by using a PCR assay designed to detect copia-like reverse transcriptase (RT) sequences. Amplification products from a genotype of each the following species Citrus sinensis, Citrus grandis, Citrus clementina, Prunus armeniaca and Prunus amygdalus, were cloned and some of them sequenced. Southern-blot hybridization using RT clones as probes showed that multiple copies are integrated throughout the citrus genome, while only 1-3 copies are detected in the P. armeniaca genome, which is in accordance with the Citrus and Prunus genome sizes. Sequence analysis of RT clones allowed a search for homologous sequences within three gene banks. The most similar ones correspond to RT domains of copia-like retrotransposons from unrelated plant species. Cluster analysis of these sequences has shown a great heterogeneity among RT domains cloned from the same genotype. This finding supports the hypothesis that horizontal transmission of retrotransposons has occurred in the past. The species presenting a RT sequence most similar to citrus RT clones is Gnetum montanum, a gymnosperm whose distribution area coincides with two of the main centers of origin of Citrus spp. A new C-methylated restriction DNA fragment containing a RT sequence is present in navel sweet oranges, but not in Valencia oranges from which the former originated suggesting, that retrotransposon activity might be, at least in part, involved in the genetic variability among sweet orange cultivars. Given that retrotransposons are quite abundant throughout the citrus genome, their activity should be investigated thoroughly before commercializing any transgenic citrus plant where the transgene(s) is part

Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing.

PubMed

Yang, Chuanyu; Powell, Charles A; Duan, Yongping; Shatters, Robert; Zhang, Muqing

2015-01-01

Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB.

Antimicrobial Nanoemulsion Formulation with Improved Penetration of Foliar Spray through Citrus Leaf Cuticles to Control Citrus Huanglongbing

PubMed Central

Yang, Chuanyu; Powell, Charles A.; Duan, Yongping; Shatters, Robert; Zhang, Muqing

2015-01-01

Huanglongbing (HLB) is the most serious disease affecting the citrus industry worldwide to date. The causal agent, Candidatus Liberibacter asiaticus (Las), resides in citrus phloem, which makes it difficult to effectively treat with chemical compounds. In this study, a transcuticular nanoemulsion formulation was developed to enhance the permeation of an effective antimicrobial compound (ampicillin; Amp) against HLB disease through the citrus cuticle into the phloem via a foliar spray. The results demonstrated that efficiency of cuticle isolation using an enzymatic method (pectinase and cellulase) was dependent on the citrus cultivar and Las-infection, and it was more difficult to isolate cuticles from valencia orange (Citrus sinensis) and HLB-symptomatic leaves. Of eight adjuvants tested, Brij 35 provided the greatest increase in permeability of the HLB-affected cuticle with a 3.33-fold enhancement of cuticular permeability over water control. An in vitro assay using Bacillus subtilis showed that nanoemulsion formulations containing Amp (droplets size = 5.26 ± 0.04 nm and 94 ± 1.48 nm) coupled with Brij 35 resulted in greater inhibitory zone diameters (5.75 mm and 6.66 mm) compared to those of Brij 35 (4.34 mm) and Amp solution (2.83 mm) alone. Furthermore, the nanoemulsion formulations eliminated Las bacteria in HLB-affected citrus in planta more efficiently than controls. Our study shows that a water in oil (W/O) nanoemulsion formulation may provide a useful model for the effective delivery of chemical compounds into citrus phloem via a foliar spray for controlling citrus HLB. PMID:26207823

Effect of genotype and environment on citrus juice carotenoid content.

PubMed

Dhuique-Mayer, Claudie; Fanciullino, Anne-Laure; Dubois, Cecile; Ollitrault, Patrick

2009-10-14

A selection of orange and mandarin varieties belonging to the same Citrus accession and cultivated in Mediterranean (Corsica), subtropical (New Caledonia), and tropical areas (principally Tahiti) were studied to assess the effect of genotype and environmental conditions on citrus juice carotenoid content. Juices from three sweet orange cultivars, that is, Pera, Sanguinelli, and Valencia ( Citrus sinensis (L.) Osbeck), and two mandarin species ( Citrus deliciosa Ten and Citrus clementina Hort. ex Tan), were analyzed by HPLC using a C(30) column. Annual carotenoid content variations in Corsican fruits were evaluated. They were found to be very limited compared to variations due to varietal influences. The statistical analysis (PCA, dissimilarity tree) results based on the different carotenoid compounds showed that citrus juice from Corsica had a higher carotenoid content than citrus juices from tropical origins. The tropical citrus juices were clearly differentiated from citrus juices from Corsica, and close correlations were obtained between beta-cryptoxanthin and phytoene (r = 0.931) and beta-carotene and phytoene (r = 0.918). More broadly, Mediterranean conditions amplified interspecific differentiation, especially by increasing the beta-cryptoxanthin and cis-violaxanthin content in oranges and beta-carotene and phytoene-phytofluene content in mandarins. Thus, at a quantitative level, environmental conditions also had a major role in determining the levels of carotenoids of nutritional interest, such as the main provitamin A carotenoids in citrus juice (beta-cryptoxanthin and beta-carotene).

Effect of orchard age on soil nitrogen transformation in subtropical China and implications.

PubMed

Zhang, Yushu; Zhang, Jinbo; Zhu, Tongbin; Müller, Christoph; Cai, Zucong

2015-08-01

A better understanding of nitrogen transformation in soils could reveal the capacity for biological inorganic N supply and improve the efficiency of N fertilizers. In this study, a (15)N tracing study was carried out to investigate the effects of converting woodland to orchard, and orchard age on the gross rates of N transformation occurring simultaneously in subtropical soils in Eastern China. The results showed that inorganic N supply rate was remained constant with soil organic C and N contents increased after converting woodland into citrus orchard and with increasing orchard age. This phenomenon was most probably due to the increase in the turnover time of recalcitrant organic-N, which increased with decreasing soil pH along with increasing orchard age significantly. The amoA gene copy numbers of both archaeal and bacterial were stimulated by orchard planting and increased with increasing orchard age. The nitrification capacity (defined as the ratio of gross rate of nitrification to total gross rate of mineralization) increased following the Michaelis-Menten equation, sharply in the first 10 years after woodland conversion to orchard, and increased continuously but much more slowly till 30 years. Due to the increase in nitrification capacity and unchanged NO3(-) consumption, the dominance of ammonium in inorganic N in woodland soil was shifted to nitrate dominance in orchard soils. These results indicated that the risk of NO3(-) loss was expected to increase and the amount of N needed from fertilizers for fruit growth did not change although soil organic N accumulated with orchard age. Copyright © 2015. Published by Elsevier B.V.

Detection of Citrus Trees from Uav Dsms

NASA Astrophysics Data System (ADS)

Ok, A. O.; Ozdarici-Ok, A.

2017-05-01

This paper presents an automated approach to detect citrus trees from digitals surface models (DSMs) as a single source. The DSMs in this study are generated from Unmanned Aerial Vehicles (UAVs), and the proposed approach first considers the symmetric nature of the citrus trees, and it computes the orientation-based radial symmetry in an efficient way. The approach also takes into account the local maxima (LM) information to verify the output of the radial symmetry. Our contributions in this study are twofold: (i) Such an integrated approach (symmetry + LM) has not been tested to detect (citrus) trees (in orchards), and (ii) the validity of such an integrated approach has not been experienced for an input, e.g. a single DSM. Experiments are performed on five test patches. The results reveal that our approach is capable of counting most of the citrus trees without manual intervention. Comparison to the state-of-the-art reveals that the proposed approach provides notable detection performance by providing the best balance between precision and recall measures.

Citrus leprosis virus N: A New Dichorhavirus Causing Citrus Leprosis Disease.

PubMed

Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Tassi, Aline Daniele; Kitajima, Elliot Watanabe; Harakava, Ricardo; Salaroli, Renato Barbosa; Freitas-Astúa, Juliana

2017-08-01

Citrus leprosis (CL) is a viral disease endemic to the Western Hemisphere that produces local necrotic and chlorotic lesions on leaves, branches, and fruit and causes serious yield reduction in citrus orchards. Samples of sweet orange (Citrus × sinensis) trees showing CL symptoms were collected during a survey in noncommercial citrus areas in the southeast region of Brazil in 2013 to 2016. Transmission electron microscopy analyses of foliar lesions confirmed the presence of rod-like viral particles commonly associated with CL in the nucleus and cytoplasm of infected cells. However, every attempt to identify these particles by reverse-transcription polymerase chain reaction tests failed, even though all described primers for the detection of known CL-causing cileviruses and dichorhaviruses were used. Next-generation sequencing of total RNA extracts from three symptomatic samples revealed the genome of distinct, although highly related (>92% nucleotide sequence identity), viruses whose genetic organization is similar to that of dichorhaviruses. The genome sequence of these viruses showed <62% nucleotide sequence identity with those of orchid fleck virus and coffee ringspot virus. Globally, the deduced amino acid sequences of the open reading frames they encode share 32.7 to 63.8% identity with the proteins of the dichorhavirids. Mites collected from both the naturally infected citrus trees and those used for the transmission of one of the characterized isolates to Arabidopsis plants were anatomically recognized as Brevipalpus phoenicis sensu stricto. Molecular and biological features indicate that the identified viruses belong to a new species of CL-associated dichorhavirus, which we propose to call Citrus leprosis N dichorhavirus. Our results, while emphasizing the increasing diversity of viruses causing CL disease, lead to a reevaluation of the nomenclature of those viruses assigned to the genus Dichorhavirus. In this regard, a comprehensive discussion is

Cyclic lipopeptides from Bacillus subtilis ABS-S14 elicit defense-related gene expression in citrus fruit

USDA-ARS?s Scientific Manuscript database

Effects of cyclic lipopeptides obtained from B. subtilis ABS-S14 on eliciting defense-related gene transcription and activity of defense-related enzymes glucanase (GLU), chitinase (CHI), peroxidase (POX) and lipoxygenase (LOX) in Citrus sinensis cv. Valencia fruit were determined. The maximum level ...

Identifying Chloris Species from Cuban Citrus Orchards and Determining Their Glyphosate-Resistance Status

PubMed Central

Bracamonte, Enzo R.; Fernández-Moreno, Pablo T.; Bastida, Fernando; Osuna, María D.; Alcántara-de la Cruz, Ricardo; Cruz-Hipolito, Hugo E.; De Prado, Rafael

2017-01-01

The Chloris genus is a C4 photosynthetic species mainly distributed in tropical and subtropical regions. Populations of three Chloris species occurring in citrus orchards from central Cuba, under long history glyphosate-based weed management, were studied for glyphosate-resistant status by characterizing their herbicide resistance/tolerance mechanisms. Morphological and molecular analyses allowed these species to be identified as C. ciliata Sw., Chloris elata Desv., and Chloris barbata Sw. Based on the glyphosate rate that causes 50% mortality of the treated plants, glyphosate resistance (R) was confirmed only in C. elata, The R population was 6.1-fold more resistant compared to the susceptible (S) population. In addition, R plants of C. elata accumulated 4.6-fold less shikimate after glyphosate application than S plants. Meanwhile, populations of C. barbata and C. ciliata with or without glyphosate application histories showed similar LD50 values and shikimic acid accumulation rates, demonstrating that resistance to glyphosate have not evolved in these species. Plants of R and S populations of C. elata differed in 14C-glyphosate absorption and translocation. The R population exhibited 27.3-fold greater 5-enolpyruvyl shikimate-3-phosphate synthase (EPSPS) activity than the S population due to a target site mutation corresponding to a Pro-106-Ser substitution found in the EPSPS gene. These reports show the innate tolerance to glyphosate of C. barbata and C. ciliata, and confirm the resistance of C. elata to this herbicide, showing that both non-target site and target-site mechanisms are involved in its resistance to glyphosate. This is the first case of herbicide resistance in Cuba. PMID:29187862

Identification of large masses of citrus fruit and rice fields in eastern Spain

NASA Technical Reports Server (NTRS)

Desagredo, F. L.; Salinas, F. G.

1973-01-01

ERTS-1 imagery has been successfully used for the identification of large areas of citrus groves and rice fields in the Valencia region of Eastern Spain. Results are encouraging and will facilitate the elaboration of a land use map with a fair degree of definition once methods prove to be fully operational.

A review of invasive alien species impacts on eucalypt stands and citrus orchards ecosystem services: towards an integrated management approach.

PubMed

Branco, Sofia; Videira, Nuno; Branco, Manuela; Paiva, Maria Rosa

2015-02-01

Multidisciplinary knowledge on the impact caused by invasive alien species (IAS) on ecosystems is crucial for guiding policy makers in the adoption of sustainable management measures. This research was focused on insect IAS impacts on two managed ecosystems: eucalypt plantations and citrus orchards. It begins with an identification of the wide range of ecosystem services (ES) and disservices provided by each of these managed ecosystems, according to the methodology proposed by the Millennium Ecosystem Assessment. Subsequently, a comprehensive review of studies that promoted the identification and valuation of direct and indirect impacts IAS impacts on these ecosystems was performed. From the synthesis of previous findings, an integrative management framework is advanced. This links the identification of ES, drivers of change and development of IAS management strategies by means of assessment processes that account for multiple dimensions of ES values. The article concludes with a discussion on the challenges underpinning assessment and valuation approaches that inform the design of inclusive strategies and interventions to tackle IAS impacts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Citrus sinensis annotation project (CAP): a comprehensive database for sweet orange genome.

PubMed

Wang, Jia; Chen, Dijun; Lei, Yang; Chang, Ji-Wei; Hao, Bao-Hai; Xing, Feng; Li, Sen; Xu, Qiang; Deng, Xiu-Xin; Chen, Ling-Ling

2014-01-01

Citrus is one of the most important and widely grown fruit crop with global production ranking firstly among all the fruit crops in the world. Sweet orange accounts for more than half of the Citrus production both in fresh fruit and processed juice. We have sequenced the draft genome of a double-haploid sweet orange (C. sinensis cv. Valencia), and constructed the Citrus sinensis annotation project (CAP) to store and visualize the sequenced genomic and transcriptome data. CAP provides GBrowse-based organization of sweet orange genomic data, which integrates ab initio gene prediction, EST, RNA-seq and RNA-paired end tag (RNA-PET) evidence-based gene annotation. Furthermore, we provide a user-friendly web interface to show the predicted protein-protein interactions (PPIs) and metabolic pathways in sweet orange. CAP provides comprehensive information beneficial to the researchers of sweet orange and other woody plants, which is freely available at http://citrus.hzau.edu.cn/.

High Incidence of Preharvest Colonization of Huanglongbing-Symptomatic Citrus sinensis Fruit by Lasiodiplodia theobromae (Diplodia natalensis) and Exacerbation of Postharvest Fruit Decay by That Fungus

PubMed Central

Zhao, Wei; Bai, Jinhe; McCollum, Greg

2014-01-01

Huanglongbing (HLB), presumably caused by the bacterium “Candidatus Liberibacter asiaticus,” is a devastating citrus disease associated with excessive preharvest fruit drop. Lasiodiplodia theobromae (diplodia) is the causal organism of citrus stem end rot (SER). The pathogen infects citrus fruit under the calyx abscission zone (AZ-C) and is associated with cell wall hydrolytic enzymes similar to plant enzymes involved in abscission. By means of DNA sequencing, diplodia was found in “Ca. Liberibacter asiaticus”-positive juice from HLB-symptomatic fruit (S) but not in “Ca. Liberibacter asiaticus”-negative juice. Therefore, the incidence of diplodia in fruit tissues, the impact on HLB-related postharvest decay, and the implications for HLB-related preharvest fruit drop were investigated in Hamlin and Valencia oranges. Quantitative PCR results (qPCR) revealed a significantly (P < 0.001) greater incidence of diplodia in the AZ-C of HLB-symptomatic (S; “Ca. Liberibacter asiaticus” threshold cycle [CT] of <30) than in the AZ-C of in asymptomatic (AS; “Ca. Liberibacter asiaticus” CT of ≥30) fruit. In agreement with the qPCR results, 2 weeks after exposure to ethylene, the incidences of SER in S fruit were 66.7% (Hamlin) and 58.7% (Valencia), whereas for AS fruit the decay rates were 6.7% (Hamlin) and 5.3% (Valencia). Diplodia colonization of S fruit AZ-C was observed by scanning electron microscopy and confirmed by PCR test and morphology of conidia in isolates from the AZ-C after surface sterilization. Diplodia CT values were negatively correlated with ethylene production (R = −0.838 for Hamlin; R = −0.858 for Valencia) in S fruit, and positively correlated with fruit detachment force (R = 0.855 for Hamlin; R = 0.850 for Valencia), suggesting that diplodia colonization in AZ-C may exacerbate HLB-associated preharvest fruit drop. PMID:25344245

Quantification of Transfer of Salmonella from Citrus Fruits to Peel, Edible Portion, and Gloved Hands during Hand Peeling.

PubMed

Jung, Jiin; Friedrich, Loretta M; Danyluk, Michelle D; Schaffner, Donald W

2017-06-01

Although studies have quantified bacterial transfer between hands and various materials, cross-contamination between the surface of fresh citrus fruit and the edible portions during hand peeling has not been reported. This study quantifies transfer of Salmonella to the edible portion of citrus fruit from a contaminated peel during hand peeling. Citrus fruits used for this study were Citrus sinensis (sweet orange) cultivars 'Valencia' and 'Navel', Citrus unshiu (Satsuma mandarins), Citrus reticulata × Citrus paradisi ('Minneola' tangelo or 'Honeybell'), and C. paradisi (grapefruit) cultivar 'Marsh'. An avirulent Salmonella Typhimurium LT2 (ATCC 700720) resistant to rifampin was used for all experiments. The inoculum containing approximately 9 log CFU/mL (50 μL) was spot inoculated onto the equator, stem, or styler of each fruit and allowed to dry for 24 h. Six volunteers put on single-use latex gloves and peeled inoculated fruit. Peel, edible fruit portion, and gloves were collected and enumerated separately. Three replicates of the study were performed in which each volunteer peeled two inoculated fruit of each variety (n = 36 fruit per variety). Cross-contamination from contaminated surface of citrus fruits to edible portion or gloved hands during peeling was affected by inoculation sites. Average Salmonella transfer to the edible portion ranged from 0.16% (Valencia inoculated at the equator) to 5.41% (navel inoculated at the stem). Average Salmonella transfer to gloved hands ranged from 0.41% (grapefruit inoculated at the stem) to 8.97% (navel inoculated at the stem). Most Salmonella remained on the peel of citrus fruits. The average level of Salmonella remaining on the peel ranged from 5.37% (Minneola inoculated at the equator) to 66.3% (Satsuma inoculated at the styler). When grapefruit was inoculated, the Salmonella that remained on the peel showed a bimodal pattern in which some individuals left almost all Salmonella on the peel, while others left

Straw Mulching Reduces the Harmful Effects of Extreme Hydrological and Temperature Conditions in Citrus Orchards

PubMed Central

Liu, Yi; Wang, Jing; Liu, Dongbi; Li, Zhiguo; Zhang, Guoshi; Tao, Yong; Xie, Juan; Pan, Junfeng; Chen, Fang

2014-01-01

Extreme weather conditions with negative impacts can strongly affect agricultural production. In the Danjiangkou reservoir area, citrus yields were greatly influenced by cold weather conditions and drought stress in 2011. Soil straw mulching (SM) practices have a major effect on soil water and thermal regimes. A two-year field experiment was conducted to evaluate whether the SM practices can help achieve favorable citrus fruit yields. Results showed that the annual total runoff was significantly (P<0.05) reduced with SM as compared to the control (CK). Correspondingly, mean soil water storage in the top 100 cm of the soil profile was increased in the SM as compared to the CK treatment. However, this result was significant only in the dry season (Jan to Mar), and not in the wet season (Jul to Sep) for both years. Interestingly, the SM treatment did not significantly increase citrus fruit yield in 2010 but did so in 2011, when the citrus crop was completely destroyed (zero fruit yield) in the CK treatment plot due to extremely low temperatures during the citrus overwintering stage. The mulch probably acted as an insulator, resulting in smaller fluctuations in soil temperature in the SM than in the CK treatment. The results suggested that the small effects on soil water and temperature changes created by surface mulch had limited impact on citrus fruit yield in a normal year (e.g., in 2010). However, SM practices can positively impact citrus fruit yield in extreme weather conditions. PMID:24489844

The Evolutionary History and Spatiotemporal Dynamics of the NC Lineage of Citrus Tristeza Virus.

PubMed

Benítez-Galeano, María José; Castells, Matías; Colina, Rodney

2017-10-12

Citrus tristeza virus (CTV) is a major pathogen affecting citrus trees worldwide. However, few studies have focused on CTV's evolutionary history and geographic behavior. CTV is locally dispersed by an aphid vector and long distance dispersion due to transportation of contaminated material. With the aim to delve deeper into the CTV-NC (New Clade) genotype evolution, we estimated an evolution rate of 1.19 × 10 -3 subs/site/year and the most common recent ancestor in 1977. Furthermore, the place of origin of the genotype was in the United States, and a great expansion of the population was observed in Uruguay. This expansion phase could be a consequence of the increment in the number of naïve citrus trees in Uruguayan orchards encompassing citrus industry growth in the past years.

Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro.

PubMed

Zhang, Lancui; Ma, Gang; Kato, Masaya; Yamawaki, Kazuki; Takagi, Toshihiko; Kiriiwa, Yoshikazu; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Nesumi, Hirohisa

2012-01-01

In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sacs in vitro were similar to those ripening on trees in the three varieties. Using this system, the changes in the carotenoid content and the expression of carotenoid metabolic genes in response to environmental stimuli were investigated. The results showed that carotenoid accumulation was induced by blue light treatment, but was not affected by red light treatment in the three varieties. Different regulation of CitPSY expression, which was up-regulated by blue light while unaffected by red light, led to different changes in carotenoid content in response to these two treatments in Satsuma mandarin and Valencia orange. In all three varieties, increases in carotenoid content were observed with sucrose and mannitol treatments. However, the accumulation of carotenoid in the two treatments was regulated by distinct mechanisms at the transcriptional level. With abscisic acid (ABA) treatment, the expression of the genes investigated in this study was up-regulated in Satsuma mandarin and Lisbon lemon, indicating that ABA induced its own biosynthesis at the transcriptional level. This feedback regulation of ABA led to decreases in carotenoid content. With gibberellin (GA) treatment, carotenoid content was significantly decreased in the three varieties. Changes in the expression of genes related to carotenoid metabolism varied among the three varieties in response to GA treatment. These results provided insights into improving carotenoid content and composition in citrus during fruit

Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro

PubMed Central

Zhang, Lancui; Ma, Gang; Kato, Masaya; Yamawaki, Kazuki; Takagi, Toshihiko; Kiriiwa, Yoshikazu; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Nesumi, Hirohisa

2012-01-01

In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sacs in vitro were similar to those ripening on trees in the three varieties. Using this system, the changes in the carotenoid content and the expression of carotenoid metabolic genes in response to environmental stimuli were investigated. The results showed that carotenoid accumulation was induced by blue light treatment, but was not affected by red light treatment in the three varieties. Different regulation of CitPSY expression, which was up-regulated by blue light while unaffected by red light, led to different changes in carotenoid content in response to these two treatments in Satsuma mandarin and Valencia orange. In all three varieties, increases in carotenoid content were observed with sucrose and mannitol treatments. However, the accumulation of carotenoid in the two treatments was regulated by distinct mechanisms at the transcriptional level. With abscisic acid (ABA) treatment, the expression of the genes investigated in this study was up-regulated in Satsuma mandarin and Lisbon lemon, indicating that ABA induced its own biosynthesis at the transcriptional level. This feedback regulation of ABA led to decreases in carotenoid content. With gibberellin (GA) treatment, carotenoid content was significantly decreased in the three varieties. Changes in the expression of genes related to carotenoid metabolism varied among the three varieties in response to GA treatment. These results provided insights into improving carotenoid content and composition in citrus during fruit

First derivative versus absolute spectral reflectance of citrus varieties

NASA Astrophysics Data System (ADS)

Blazquez, Carlos H.; Nigg, H. N.; Hedley, Lou E.; Ramos, L. E.; Sorrell, R. W.; Simpson, S. E.

1996-06-01

Spectral reflectance measurements from 400 to 800 nm were taken from immature and mature leaves of grapefruit ('McCarty' and 'Rio Red'), 'Minneola' tangelo, 'Satsuma' mandarin, 'Dancy' tangerine, 'Nagami' oval kumquat, and 'Valencia' sweet orange, at the Florida Citrus Arboretum, Division of Plant Industry, Winter Haven, Florida. Immature and mature leaves of 'Minneola' tangelo had greater percent reflectance in the 400 to 800 nm range than the other varieties and leaf ages measured. The slope of the citrus spectral curves in the 800 nm range was not as sharp as conventional spectrometers, but had a much higher reflectance value than those obtained with a DK-2 spectrometer. Statistical analyses of absolute spectral data yielded significant differences between mature and immature leaves and between varieties. First derivative data analyses did not yield significant differences between varieties.

Timing of the inhibitory effect of fruit on return bloom of 'Valencia' sweet orange (Citrus sinensis (L.) Osbeck).

PubMed

Martínez-Fuentes, Amparo; Mesejo, Carlos; Reig, Carmina; Agustí, Manuel

2010-08-30

In Citrus the inhibitory effect of fruit on flower formation is the main cause of alternate bearing. Although there are some studies reporting the effect on flowering of the time of fruit removal in a well-defined stage of fruit development, few have investigated the effect throughout the entire fruit growth stage from early fruitlet growth to fruit maturity. The objective of this study was to determine the phenological fruit developmental stage at which the fruit begins its inhibitory effect on flowering in sweet orange by manual removal of fruits, and the role of carbohydrates and nitrogen in the process. Fruit exerted its inhibitory effect from the time it was close to reaching its maximum weight, namely 90% of its final size (November) in the present experiments, to bud sprouting (April). The reduction in flowering paralleled the reduction in bud sprouting. This reduction was due to a decrease in the number of generative sprouted buds, whereas mixed-typed shoots were largely independent of the time of fruit removal, and vegetative shoots increased in frequency. The number of leaves and/or flowers per sprouted shoot was not significantly modified by fruit load. In 'Valencia' sweet orange, fruit inhibits flowering from the time it completes its growth. Neither soluble sugar content nor starch accumulation in leaves due to fruit removal was related to flowering intensity, but some kind of imbalance in nitrogen metabolism was observed in trees tending to flower scarcely. Copyright (c) 2010 Society of Chemical Industry.

Isolation and identification of entomopathogenic nematodes from citrus orchards in South Africa and their biocontrol potential against false codling moth.

PubMed

Malan, Antoinette P; Knoetze, Rinus; Moore, Sean D

2011-10-01

A survey was conducted to determine the diversity and frequency of endemic entomopathogenic nematodes (EPN) in citrus orchards in the Western Cape, Eastern Cape and Mpumalanga provinces of South Africa. The main aim of the survey was to obtain nematodes as biological control agents against false codling moth (FCM), Thaumatotibia leucotreta, a key pest of citrus in South Africa. From a total of 202 samples, 35 (17%) tested positive for the presence of EPN. Of these, four isolates (11%) were found to be steinernematids, while 31 (89%) were heterorhabditids. Sequencing and characterisation of the internal transcribed spacer (ITS) region was used to identify all nematode isolates to species level. Morphometrics, morphology and biology of the infective juvenile (IJ) and the first-generation male were used to support molecular identification and characterisation. The Steinernema spp. identified were Steinernema khoisanae, Steinernema yirgalemense and Steinernema citrae. This is the first report of S. yirgalemense in South Africa, while for S. citrae it is the second new steinernematid to be identified from South Africa. Heterorhabditis species identified include Heterorhabditis bacteriophora, Heterorhabditis zealandica and an unknown species of Heterorhabditis. Laboratory bioassays, using 24-well bioassay disks, have shown isolates of all six species found during the survey, to be highly virulent against the last instar of FCM larvae. S. yirgalemense, at a concentration of 50IJs/FCM larva caused 100% mortality and 74% at a concentration of 200IJs/pupa. Using a sand bioassay, S. yirgalemense gave 93% control of cocooned pupae and emerging moths at a concentration of 20IJs/cm(2). This is the first report on the potential use of EPN to control the soil-borne life stages of FCM, which includes larvae, pupae and emerging moths. It was shown that emerging moths were infected with nematodes, which may aid in control and dispersal. Copyright © 2011 Elsevier Inc. All rights

Adventive plants from ovules and nucelli in Citrus.

PubMed

Kochba, J; Spiegel-Roy, P; Safran, H

1972-09-01

1- to 8-week-old ovules and nucelli from three Citrus cultivars-Shamouti and Valencia (Citrus sinensis) oranges and Marsh Seedless (C. paradisi) grapefruit-were cultured in vitro. No embryo differentiation was observed in the explants prior to culture. The Shamouti ovules had degenerated and were apparently unfertilized. Embryoids formed on Murashige and Tucker nutrient medium supplemented with 500 mg/l malt extract. Whole plants developed on the same basal medium supplemented with kinetin and indole-3-acetic acid (IAA), coconut milk or gibberellic acid (GA3). A higher kinetin/IAA ratio or the addition of coconut milk favoured stem elongation more than root formation while a lower kinetin/IAA ratio favoured root formation and inhibited stem elongation. The addition of GA3 to the basal medium stimulated rooting and stem elongation. These results can be of aid in mutation research, allowing irradiation at stages prior to embryonic development.

Data on morphological features of mycosis induced by Colletotrichum nymphaeae and Lecanicillium longisporum on citrus orthezia scale.

PubMed

Mascarin, Gabriel Moura; Guarín-Molina, Juan Humberto; Arthurs, Steven Paul; Humber, Richard Alan; de Andrade Moral, Rafael; Demétrio, Clarice Garcia Borges; Delalibera, Ítalo

2016-09-01

We describe symptoms of mycosis induced by two native fungal entomopathogens of the citrus orthezia scale, Praelongorthezia praelonga (Hemiptera: Ortheziidae), an important pest of citrus orchards. The data presented in this article are related to the article entitled "Seasonal prevalence of the insect pathogenic fungus Colletotrichum nymphaeae in Brazilian citrus groves under different chemical pesticide regimes" [1]. The endemic fungal pathogen, C. nymphaeae, emerges through the thin cuticular intersegmental regions of the citrus orthezia scale body revealing orange salmon-pigmented conidiophores bearing conidial masses, as well as producing rhizoid-like hyphae that extend over the citrus leaf. By contrast, nymphs or adult females of this scale insect infected with Lecanicillium longisporum exhibit profuse outgrowth of bright white-pigmented conidiophores with clusters of conidia emerging from the insect intersegmental membranes, and mycosed cadavers are commonly observed attached to the leaf surface by hyphal extensions. These morphological differences are important features to discriminate these fungal entomopathogens in citrus orthezia scales.

Host status of grapefruit and Valencia oranges for Anastrepha serpentina and Anastrepha ludens (Diptera: Tephritidae).

PubMed

Mangan, Robert L; Thomas, Donald B; Moreno, Aleena M Tarshis

2011-04-01

Anastrepha serpentina (Wiedemann) (Diptera: Tephritidae) is sporadically captured in the Rio Grande Valley of Texas. Although its preferred hosts are in the Sapotaceae family, several varieties of Citrus, including grapefruit and oranges are listed as alternate hosts. Although Mexican fruit fly, Anastrepha ludens (Loew), is known to be a major pest of Citrus, doubt exists as to the status of Citrus as a breeding host for A. serpentina. To evaluate the host status of commercial Citrus for A. serpentina we compared oviposition and development with that of A. ludens under laboratory conditions with 'Rio Red' grapefruit (Citrus paradisi MacFayden) and 'Valencia' oranges [Citrus sinensis (L.) Osbeck] in different stages of maturity. Both fly species oviposited in early season fruit in which the eggs and larvae died in the fruit albedo. Survival of either species to the adult stage occurred in later season grapefruit. In oranges, no A. serpentina larvae survived compared with 150 A. ludens surviving to adults. Survival on both Citrus species was much lower for A. serpentina, only approximately 5% of eggs eclosed into larvae in grapefruit compared with approximatley 50% for A. ludens. In oranges approximately 16% of A. serpentina eggs eclosed compared with approximately 76% for A. ludens. In grapefruit, only one fourth as many A. serpentina larvae survived to the adult stage compared with A. ludens. Additional experiments were performed in a greenhouse on small, caged trees of la coma (Sideroxylon celastrinum H.B.K.), a Texas species of Sapotaceae. The A. serpentina females readily oviposited into these berries and normal adults emerged. The present low incidence of the adults, coupled with the high mortality during development of the larvae, suggests that Texas citrus is unlikely to support a breeding population of A. serpentina.

Shikimic Acid Monitoring by HPLC with Diode Array Detector in Citrus sinensis Orchard with Glyphosate

USDA-ARS?s Scientific Manuscript database

This study was conducted to evaluate the effect of weed control with glyphosate on shikimic acid levels in citrus, “Pêra” cultivar. The experimental plots were set in Santo Antônio de Posse county, Sao Paulo State, Brazil with the following treatments: glyphosate at 1,440 g.ha-1 a.e. between citrus ...

Hydrogen cyanamide on citrus: preliminary data on phytotoxicity and influence on flush in potted and field trees

USDA-ARS?s Scientific Manuscript database

Bloom in individual citrus trees typically continues for more than a month in south Florida, with even greater bloom duration within most orchard blocks because of variation in bloom timing between trees. Prolonged bloom contributes to variable fruit maturity as harvest approaches and increases seve...

Conservation strategies on citrus plantation in eastern Spain. Catch crops, geotextiles and mulches

NASA Astrophysics Data System (ADS)

Cerdà, Artemi; Dominguez, Alfons; Giménez Morera, Antonio

2010-05-01

Tillage (6 %), and herbicides (89 %) are the most widespread soil management methods in eastern Spain citrus orchards. The bare soils, the high intensity thunderstorms and the steep slopes result in high erosion rates. Over the last 3 years an experimental station has been developed at Montesa municipality in order to determine the effect of different types of mulch, geotextiles and catch crops. Rainfall simulation experiments on 20 m2 plots shown that soil losses can be control by catch crops (85 %), chipped pruned branches (89 %), straw mulch (97 %) and geotextiles (99 %). Then, vegetation can contribute to control the soil and water losses on the highly erodible soil of Mediterranean orchards.

PROCENTAJE DE PSILIDOS PORTADORES DE Canidatus Liberibacter asiaticus Y SU RELACION CON LA INCIDENCIA DE HLB EN CINCO HUERTAS COMERCIALES DE LIMON MEXICANO {Citrus aurantifolia (Christm) Swingle} EN EL ESTADO DE COLIMA MEXICO

USDA-ARS?s Scientific Manuscript database

Asian citrus psyllids (Diaphorina citri) were individually analyzed by qPCR to detect Candidatus Liberibacter asiaticus (CLas). The psyllids were collected in Mexican lime (Citrus aurantifolia) trees in five commercial orchards in Tecomán and Manzanillo, Colima with severe symptoms of classical mott...

[Estimation and Visualization of Nitrogen Content in Citrus Canopy Based on Two Band Vegetation Index (TBVI)].

PubMed

Wang, Qiao-nan; Ye, Xu-jun; Li, Jin-meng; Xiao, Yu-zhao; He, Yong

2015-03-01

Nitrogen is a necessary and important element for the growth and development of fruit orchards. Timely, accurate and nondestructive monitoring of nitrogen status in fruit orchards would help maintain the fruit quality and efficient production of the orchard, and mitigate the pollution of water resources caused by excessive nitrogen fertilization. This study investigated the capability of hyperspectral imagery for estimating and visualizing the nitrogen content in citrus canopy. Hyperspectral images were obtained for leaf samples in laboratory as well as for the whole canopy in the field with ImSpector V10E (Spectral Imaging Ltd., Oulu, Finland). The spectral datas for each leaf sample were represented by the average spectral data extracted from the selected region of interest (ROI) in the hyperspectral images with the aid of ENVI software. The nitrogen content in each leaf sample was measured by the Dumas combustion method with the rapid N cube (Elementar Analytical, Germany). Simple correlation analysis and the two band vegetation index (TBVI) were then used to develop the spectra data-based nitrogen content prediction models. Results obtained through the formula calculation indicated that the model with the two band vegetation index (TBVI) based on the wavelengths 811 and 856 nm achieved the optimal estimation of nitrogen content in citrus leaves (R2 = 0.607 1). Furthermore, the canopy image for the identified TBVI was calculated, and the nitrogen content of the canopy was visualized by incorporating the model into the TBVI image. The tender leaves, middle-aged leaves and elder leaves showed distinct nitrogen status from highto low-levels in the canopy image. The results suggested the potential of hyperspectral imagery for the nondestructive detection and diagnosis of nitrogen status in citrus canopy in real time. Different from previous studies focused on nitrogen content prediction at leaf level, this study succeeded in predicting and visualizing the nutrient

Leaf photosynthetic and water-relations responses for 'Valencia' orange trees exposed to oxidant air pollution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszyk, D.M.; Takemoto, B.K.; Poe, M.

1991-01-01

Leaf responses were measured to test a hypothesis that reduced photosynthetic capacity and/or altered water relations were associated with reductions in yield for 'Valencia' orange trees (Citrus sinensis (L.), Osbeck) exposed to ambient oxidant air pollution. Exposures were continuous for 4 years to three levels of oxidants (in charcoal-filtered, half-filtered, and non-filtered air). Oxidants had no effect on net leaf photosynthetic rates or on photosynthetic pigment concentrations. A single set of measurements indicated that oxidants increased leaf starch concentrations (24%) prior to flowering, suggesting a change in photosynthate allocation. Leaves exposed to oxidants had small, but consistent, changes in watermore » relations over the summer growing season, compared to trees growing in filtered air. Other changes included decreased stomatal conductance (12%) and transpiration (9%) rates, and increased water pressure potentials (5%). While all responses were subtle, their cumulative impact over 4 years indicated that 'Valencia' orange trees were subject to increased ambient oxidant stress.« less

Detection of Anomalies in Citrus Leaves Using Laser-Induced Breakdown Spectroscopy (LIBS).

PubMed

Sankaran, Sindhuja; Ehsani, Reza; Morgan, Kelly T

2015-08-01

Nutrient assessment and management are important to maintain productivity in citrus orchards. In this study, laser-induced breakdown spectroscopy (LIBS) was applied for rapid and real-time detection of citrus anomalies. Laser-induced breakdown spectroscopy spectra were collected from citrus leaves with anomalies such as diseases (Huanglongbing, citrus canker) and nutrient deficiencies (iron, manganese, magnesium, zinc), and compared with those of healthy leaves. Baseline correction, wavelet multivariate denoising, and normalization techniques were applied to the LIBS spectra before analysis. After spectral pre-processing, features were extracted using principal component analysis and classified using two models, quadratic discriminant analysis and support vector machine (SVM). The SVM resulted in a high average classification accuracy of 97.5%, with high average canker classification accuracy (96.5%). LIBS peak analysis indicated that high intensities at 229.7, 247.9, 280.3, 393.5, 397.0, and 769.8 nm were observed of 11 peaks found in all the samples. Future studies using controlled experiments with variable nutrient applications are required for quantification of foliar nutrients by using LIBS-based sensing.

Scientific critique of the paper “Climatic distribution of citrus black spot caused by Phyllosticta citricarpa. A historical analysis of disease spread in South Africa” by Martínez-Minaya et al. (2015)

USDA-ARS?s Scientific Manuscript database

The global potential distribution of Phyllosticta citricarpa, the causal organism of citrus black spot (CBS), is at the heart of an ongoing debate on the level of potential pest risk posed by P. citricarpa to citrus producing orchards within the European Union (EU). The EU currently regulates the i...

The Asian citrus psyllid host Murraya koenigii is immune to citrus Huanglongbing pathogen 'Candidatus Liberibacter asiaticus'.

PubMed

Beloti, Vitor Hugo; Alves, Gustavo; Coletta-Filho, Helvécio; Yamamoto, Pedro

2018-04-12

The Asian citrus psyllid (ACP) Diaphorina citri, vector of 'Candidatus Liberibacter asiaticus' (CLas), the putative causal agent of citrus Huanglongbing (HLB), is controlled by application of insecticides, which, although effective, has resulted in serious biological imbalances. New management tools are needed, and the technique known as 'trap crop' has been attracting attention. A potential plant for use as a trap crop in the management of the ACP is Murraya koenigii (curry leaf). However, for this plant to be used in the field, it needs to be attractive for the vector and must not harbor CLas. To verify the potential of curry leaf as trap crop for the management of HLB, we investigated the ability of D. citri to transmit CLas to M. koenigii, and to other test plants, including M. paniculata (orange jasmine) and 'Valencia' sweet-orange seedlings. For the tests, the insects were reared on a symptomatic CLas-infected plant and allowed to feed on the three test plant species. The overall maximum transmission rate for the citrus seedlings was 83.3%, and for orange jasmine was 33.3%. Successful transmission of CLas by ACP to the curry-leaf seedlings was not observed, and it was treated as immune to CLas. Supported by the previous results that M. koenigii is attractive for ACP, these results indicate that curry leaf is an excellent candidate for use as a trap crop, to improve the management of the insect vector and consequently of HLB.

Dispersion patterns and sampling plans for Diaphorina citri (Hemiptera: Psyllidae) in citrus.

PubMed

Sétamou, Mamoudou; Flores, Daniel; French, J Victor; Hall, David G

2008-08-01

The abundance and spatial dispersion of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) were studied in 34 grapefruit (Citrus paradisi Macfad.) and six sweet orange [Citrus sinensis (L.) Osbeck] orchards from March to August 2006 when the pest is more abundant in southern Texas. Although flush shoot infestation levels did not vary with host plant species, densities of D. citri eggs, nymphs, and adults were significantly higher on sweet orange than on grapefruit. D. citri immatures also were found in significantly higher numbers in the southeastern quadrant of trees than other parts of the canopy. The spatial distribution of D. citri nymphs and adults was analyzed using Iowa's patchiness regression and Taylor's power law. Taylor's power law fitted the data better than Iowa's model. Based on both regression models, the field dispersion patterns of D. citri nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. For the average density of each life stage obtained during our surveys, the minimum number of flush shoots per tree needed to estimate D. citri densities varied from eight for eggs to four flush shoots for adults. Projections indicated that a sampling plan consisting of 10 trees and eight flush shoots per tree would provide density estimates of the three developmental stages of D. citri acceptable enough for population studies and management decisions. A presence-absence sampling plan with a fixed precision level was developed and can be used to provide a quick estimation of D. citri populations in citrus orchards.

Assessing the performance of surface and subsurface drip systems on irrigation water use efficiency of citrus orchards in Spain

NASA Astrophysics Data System (ADS)

Amparo Martinez-Gimeno, Maria; Provenzano, Giuseppe; Bonet, Luis; Intrigliolo, Diego S.; Badal, Eduardo; Ballestrer, Carlos

2017-04-01

In Mediterranean countries, water scarcity represents a real environmental concern at present and, according to the current climate change models predictions, the problem will be amplified in the future. In order to deal with this issue, application of strategies aimed to optimize the water resources in agriculture and to increase water use efficiency have become essential. On the one hand, it is important the election of the appropriate irrigation system for each particular case. On the other hand, identify the best management options for that specific irrigation system is crucial to optimize the available water resources without affecting yield. When using water saving strategies, however, it is a must to monitor the soil and/or crop water status in order to know the level of stress reached by the plants and to avoid levels that could lead to detrimental effects on yield. Stem water potential, ψstem, expressing the instantaneous condition of crop water stress, is considered a robust indicator of crop water status. The main objective of this study was to assess the performance of a surface (DI) and subsurface (SDI) drip irrigation system in a citrus orchard with 7 (DI7, SDI7) or 14 emitters (DI14, SDI14) per plant, in terms of irrigation water use efficiency (IWUE) and possible amount of water saving. The experiment was carried out in 2014 and 2015 in Alberique, Spain, (39˚ 7'31" N, 0˚ 33'17" W), in a commercial orchard (Citrus clementina, Hort. ex Tan. 'Arrufatina') in which four different treatments with three replications (12 sub-plots) were prepared according to a complete randomized block design. Irrigation doses and timing were scheduled based on the estimated maximum crop evapotranspiration corrected according to measurements of ψstem and soil water content, and weather forecasts. In order to limit the maximum crop water stress, the thresholds of ψstem were assumed in the range between -0.8 and -1.0 MPa from January to June and between -1.0 and -1

Regulation of ascorbic acid metabolism by blue LED light irradiation in citrus juice sacs.

PubMed

Zhang, Lancui; Ma, Gang; Yamawaki, Kazuki; Ikoma, Yoshinori; Matsumoto, Hikaru; Yoshioka, Terutaka; Ohta, Satoshi; Kato, Masaya

2015-04-01

In the present study, the effects of red and blue LED lights on the accumulation of ascorbic acid (AsA) were investigated in the juice sacs of three citrus varieties, Satsuma mandarin, Valencia orange, and Lisbon lemon. The results showed that the blue LED light treatment effectively increased the AsA content in the juice sacs of the three citrus varieties, whereas the red LED light treatment did not. By increasing the blue LED light intensity, the juice sacs of the three citrus varieties accumulated more AsA. Moreover, continuous irradiation with blue LED light was more effective than pulsed irradiation for increasing the AsA content in the juice sacs of the three citrus varieties. Gene expression results showed that the modulation of AsA accumulation by blue LED light was highly regulated at the transcription level. The up-regulation of AsA biosynthetic genes (CitVTC1, CitVTC2, CitVTC4, and CitGLDH), AsA regeneration genes (CitMDAR1, CitMDAR2, and CitDHAR) and two GSH-producing genes (CitGR and CitchGR) contributed to these increases in the AsA content in the three citrus varieties. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Time Series Analysis of Remote Sensing Observations for Citrus Crop Growth Stage and Evapotranspiration Estimation

NASA Astrophysics Data System (ADS)

Sawant, S. A.; Chakraborty, M.; Suradhaniwar, S.; Adinarayana, J.; Durbha, S. S.

2016-06-01

Satellite based earth observation (EO) platforms have proved capability to spatio-temporally monitor changes on the earth's surface. Long term satellite missions have provided huge repository of optical remote sensing datasets, and United States Geological Survey (USGS) Landsat program is one of the oldest sources of optical EO datasets. This historical and near real time EO archive is a rich source of information to understand the seasonal changes in the horticultural crops. Citrus (Mandarin / Nagpur Orange) is one of the major horticultural crops cultivated in central India. Erratic behaviour of rainfall and dependency on groundwater for irrigation has wide impact on the citrus crop yield. Also, wide variations are reported in temperature and relative humidity causing early fruit onset and increase in crop water requirement. Therefore, there is need to study the crop growth stages and crop evapotranspiration at spatio-temporal scale for managing the scarce resources. In this study, an attempt has been made to understand the citrus crop growth stages using Normalized Difference Time Series (NDVI) time series data obtained from Landsat archives (http://earthexplorer.usgs.gov/). Total 388 Landsat 4, 5, 7 and 8 scenes (from year 1990 to Aug. 2015) for Worldwide Reference System (WRS) 2, path 145 and row 45 were selected to understand seasonal variations in citrus crop growth. Considering Landsat 30 meter spatial resolution to obtain homogeneous pixels with crop cover orchards larger than 2 hectare area was selected. To consider change in wavelength bandwidth (radiometric resolution) with Landsat sensors (i.e. 4, 5, 7 and 8) NDVI has been selected to obtain continuous sensor independent time series. The obtained crop growth stage information has been used to estimate citrus basal crop coefficient information (Kcb). Satellite based Kcb estimates were used with proximal agrometeorological sensing system

Evidence for host plant preference by Iphiseiodes quadripilis (Acari: Phytoseiidae) on Citrus.

PubMed

Villanueva, Raul T; Childers, Carl C

2006-01-01

In this study, we present field and laboratory evidence on the preference of Iphiseiodes quadripilis (Banks) for grapefruit (Citrus paradisi Macfadyen) leaves compared with sweet orange (Citrus sinensis (L.) Osbeck) leaves. This preference was confirmed in four orchards whether leaf samples were taken from either border trees of contiguous grapefruit or sweet orange or interior row trees with both citrus species in adjacent rows. Iphiseiodes quadripilis was most abundant in grapefruit trees in spite of the greater abundance of the Texas citrus mite, Eutetranychus banksi (McGregor) (Acari: Tetranychidae) in sweet orange trees. Similar preference responses were observed in laboratory tests using a Y-tube olfactometer whether I. quadripilis were collected from sweet orange or grapefruit. Iphiseiodes quadripilis collected from grapefruit trees showed significant preference for grapefruit over sweet orange leaves in contact choice tests using an arena of alternating leaf strips (12 mm long x 2 mm wide) of sweet orange and grapefruit. However, I. quadripilis collected from sweet orange trees did not show preference for either grapefruit or sweet orange leaves. Based on these results, grapefruit leaves foster some unknown factor or factors that retain I. quadripilis in greater numbers compared with sweet orange leaves.

Local genetic diversity of Xanthomonas citri subsp. citri in citrus orchards in northwest Paraná state, Brazil

USDA-ARS?s Scientific Manuscript database

Xanthomonas citri subsp. citri, causal agent of Asiatic citrus canker, is an important pathogen of citrus in Brazil and elsewhere. The genetic diversity of X. citri subsp. citri pathtype ‘A’ has not been studied in Brazil at a local scale (up to 300 km). A total of 40 isolates were collected from le...

Characterization of Mycosphaerellaceae species associated with citrus greasy spot in Panama and Spain.

PubMed

Aguilera-Cogley, Vidal Antonio; Berbegal, Mónica; Català, Santiago; Brentu, Francis Collison; Armengol, Josep; Vicent, Antonio

2017-01-01

Greasy spot of citrus, caused by Zasmidium citri-griseum (= Mycosphaerella citri), is widely distributed in the Caribbean Basin, inducing leaf spots, premature defoliation, and yield loss. Greasy spot-like symptoms were frequently observed in humid citrus-growing regions in Panama as well as in semi-arid areas in Spain, but disease aetiology was unknown. Citrus-growing areas in Panama and Spain were surveyed and isolates of Mycosphaerellaceae were obtained from citrus greasy spot lesions. A selection of isolates from Panama (n = 22) and Spain (n = 16) was assembled based on their geographical origin, citrus species, and affected tissue. The isolates were characterized based on multi-locus DNA (ITS and EF-1α) sequence analyses, morphology, growth at different temperatures, and independent pathogenicity tests on the citrus species most affected in each country. Reference isolates and sequences were also included in the analysis. Isolates from Panama were identified as Z. citri-griseum complex, and others from Spain attributed to Amycosphaerella africana. Isolates of the Z. citri-griseum complex had a significantly higher optimal growth temperature (26.8°C) than those of A. africana (19.3°C), which corresponded well with their actual biogeographical range. The isolates of the Z. citri-griseum complex from Panama induced typical greasy spot symptoms in 'Valencia' sweet orange plants and the inoculated fungi were reisolated. No symptoms were observed in plants of the 'Ortanique' tangor inoculated with A. africana. These results demonstrate the presence of citrus greasy spot, caused by Z. citri-griseum complex, in Panama whereas A. africana was associated with greasy spot-like symptoms in Spain.

Orchard and nursery dynamics of the effect of interplanting citrus with guava for Huanglongbing, vector, and disease management

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important pest of citrus in the United States of America primarily because it vectors ‘Candidatus Liberibacter asiaticus’, the bacterium putatively responsible for Asiatic huanglongbing (HLB). Asiatic HLB is con...

DNA Barcode Reference Library for the African Citrus Triozid, Trioza erytreae (Hemiptera: Triozidae): Vector of African Citrus Greening.

PubMed

Khamis, F M; Rwomushana, I; Ombura, L O; Cook, G; Mohamed, S A; Tanga, C M; Nderitu, P W; Borgemeister, C; Sétamou, M; Grout, T G; Ekesi, S

2017-12-05

Citrus (Citrus spp.) production continues to decline in East Africa, particularly in Kenya and Tanzania, the two major producers in the region. This decline is attributed to pests and diseases including infestation by the African citrus triozid, Trioza erytreae (Del Guercio) (Hemiptera: Triozidae). Besides direct feeding damage by adults and immature stages, T. erytreae is the main vector of 'Candidatus Liberibacter africanus', the causative agent of Greening disease in Africa, closely related to Huanglongbing. This study aimed to generate a novel barcode reference library for T. erytreae in order to use DNA barcoding as a rapid tool for accurate identification of the pest to aid phytosanitary measures. Triozid samples were collected from citrus orchards in Kenya, Tanzania, and South Africa and from alternative host plants. Sequences generated from populations in the study showed very low variability within acceptable ranges of species. All samples analyzed were linked to T. erytreae of GenBank accession number KU517195. Phylogeny of samples in this study and other Trioza reference species was inferred using the Maximum Likelihood method. The phylogenetic tree was paraphyletic with two distinct branches. The first branch had two clusters: 1) cluster of all populations analyzed with GenBank accession of T. erytreae and 2) cluster of all the other GenBank accession of Trioza species analyzed except T. incrustata Percy, 2016 (KT588307.1), T. eugeniae Froggatt (KY294637.1), and T. grallata Percy, 2016 (KT588308.1) that occupied the second branch as outgroups forming sister clade relationships. These results were further substantiated with genetic distance values and principal component analyses. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Differentiation between Flavors of Sweet Orange (Citrus sinensis) and Mandarin (Citrus reticulata).

PubMed

Feng, Shi; Suh, Joon Hyuk; Gmitter, Frederick G; Wang, Yu

2018-01-10

Pioneering investigations referring to citrus flavor have been intensively conducted. However, the characteristic flavor difference between sweet orange and mandarin has not been defined. In this study, sensory analysis illustrated the crucial role of aroma in the differentiation between orange flavor and mandarin flavor. To study aroma, Valencia orange and LB8-9 mandarin were used. Their most aroma-active compounds were preliminarily identified by aroma extract dilution analysis (AEDA). Quantitation of key volatiles followed by calculation of odor activity values (OAVs) further detected potent components (OAV ≥ 1) impacting the overall aromatic profile of orange/mandarin. Follow-up aroma profile analysis revealed that ethyl butanoate, ethyl 2-methylbutanoate, octanal, decanal, and acetaldehyde were essential for orange-like aroma, whereas linalool, octanal, α-pinene, limonene, and (E,E)-2,4-decadienal were considered key components for mandarin-like aroma. Furthermore, an unreleased mandarin hybrid producing fruit with orange-like flavor was used to validate the identification of characteristic volatiles in orange-like aroma.

Modelling the effect of an alternative host population on the spread of citrus Huanglongbing

NASA Astrophysics Data System (ADS)

d'A. Vilamiu, Raphael G.; Ternes, Sonia; Laranjeira, Francisco F.; de C. Santos, Tâmara T.

2013-10-01

The objective of this work was to model the spread of citrus Huanglongbing (HLB) considering the presence of a population of alternative hosts (Murraya paniculata). We developed a compartmental deterministic mathematical model for representing the dynamics of HLB disease in a citrus orchard, including delays in the latency and incubation phases of the disease in the plants and a delay period on the nymphal stage of Diaphorina citri, the insect vector of HLB in Brazil. The results of numerical simulations indicate that alternative hosts should not play a crucial role on HLB dynamics considering a typical scenario for the Recôncavo Baiano region in Brazil . Also, the current policy of removing symptomatic plants every three months should not be expected to significantly hinder HLB spread.

Introduction and characterization of charged functional domains into an esterified pectic homogalacturonan by a citrus pectin methylesterase and comparison of its modes of action to other pectin methylesterase isozymes

USDA-ARS?s Scientific Manuscript database

One of the four pectin methylesterase isozymes isolated from Citrus sinensis variety Valencia fruit was used to demethylesterify a model homogalacturonan to 30%, 50% and 70% degree of methylesterification at pH 4.5 and 7.0, respectively. Introduced demethylesterified blocks were released by a limite...

Aggregation Patterns, Sampling Plan, and Economic Injury Levels for the New Citrus Pest Delottococcus aberiae (Hemiptera: Pseudococcidae).

PubMed

Pérez-Rodríguez, J; Martínez-Blay, V; Soto, A; Selfa, J; Monzó, C; Urbaneja, A; Tena, A

2017-12-05

Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is the latest exotic mealybug species introduced in citrus in the Mediterranean basin. It causes severe distortion and size reduction on developing fruits. Due to its first interaction with citrus, D. aberiae economic thresholds are still unknown for this crop and the current Integrated Pest Management programs have been disrupted. The objectives of this study were to determine the aggregation patterns of D. aberiae in citrus, develop an efficient sampling plan to assess its population density, and calculate its Economic and Economic Environmental Injury Levels (EIL and EEIL, respectively). Twelve and 19 orchards were sampled in 2014 and 2015, respectively. At each orchard, population densities were monitored fortnightly in leaves, twigs, and fruit, and fruit damage was determined at harvest. Our results showed a clumped aggregation of D. aberiae in all organs with no significant differences between generations on fruit. Fruit damage at harvest was strongly correlated with fruit occupation in spring. Based on these results and using chlorpyrifos as the insecticide of reference, the EIL and EEIL were calculated as 7.1 and 12.1% of occupied fruit in spring, respectively. With all this, we recommend sampling 275 fruits using a binomial sampling method or alternatively, 140 fruits with an enumerative method bimonthly between petal fall and July. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Citrus leprosis and its status in Florida and Texas: past and present.

PubMed

Childers, C C; Rodrigues, J C V; Derrick, K S; Achor, D S; French, J V; Welbourn, W C; Ochoa, R; Kitajima, E W

2003-01-01

According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus industry prior to 1925. This was supported with photographs showing typical leprosis symptoms on citrus leaves, fruit, and twigs. Support for the past occurrence of citrus leprosis in Florida includes: (1) presence of twig lesions in affected orange blocks in addition to lesions on fruits and leaves and corresponding absence of similar lesions on grapefruit; (2) yield reduction and die-back on infected trees; and (3) spread of the disease between 1906 and 1925. Transmission electron microscopy (TEM) examination of tissue samples from leprosis-like injuries to orange and grapefruit leaves from Florida in 1997, and fruits from grapefruit and sweet orange varieties from Texas in 1999 and 2000 did not contain leprosis-like viral particles or viroplasm inclusions. In contrast, leprosis viroplasm inclusions were readily identified by TEM within green non-senescent tissues surrounding leprosis lesions in two of every three orange leaf samples and half of the fruit samples obtained from Piracicaba, Brazil. Symptoms of leprosis were not seen in any of the 24,555 orange trees examined across Florida during 2001 and 2002. The authors conclude that citrus leprosis no longer exists in Florida nor occurs in Texas citrus based on: (1) lack of leprosis symptoms on leaves, fruit, and twigs of sweet orange citrus varieties surveyed in Florida: (2) failure to find virus particles or viroplasm inclusion bodies in suspect samples from both Florida and Texas examined by TEM; (3) absence of documented reports by others on the presence of characteristic leprosis symptoms in Florida; (4) lack of its documented occurrence in dooryard trees or abandoned or minimal pesticide citrus orchard sites in Florida. In view of the serious threat to citrus in the U.S., every effort must be taken to quarantine the importation of both citrus and woody ornamental plants that serve as hosts for Brevipalpus

Response of citrus and other selected plant species to simulated HCL - acid rain

NASA Technical Reports Server (NTRS)

Knott, W. M.; Heagle, A. S.

1980-01-01

Mature valencia orange trees were sprayed with hydrochloric acid solutions (pH 7.8, 2.0, 1.0, and 0.5) in the field at the full bloom stage and at one month after fruit set. Potted valencia orange and dwarf citrus trees, four species of plants native to Merritt Island, and four agronomic species were exposed to various pH levels of simulated acid rain under controlled conditions. The acid rain was generated from dilutions of hydrochloric acid solutions or by passing water through an exhaust generated by burning solid rocket fuel. The plants were injured severely at pH levels below 1.0, but showed only slight injury at pH levels of 2.0 and above. Threshold injury levels were between 2.0 and 3.0 pH. The sensitivity of the different plant species to acid solutions was similar. Foliar injury symptoms were representative of acid rain including necrosis of young tissue, isolated necrotic spots or patches, and leaf abscission. Mature valencia orange trees sprayed with concentrations of 1.0 pH and 0.5 pH in the field had reduced fruit yields for two harvests after the treatment. All experimental trees were back to full productivity by the third harvest after treatment.

In vitro effects of citrus oils against Mycobacterium tuberculosis and non-tuberculous Mycobacteria of clinical importance.

PubMed

Crandall, Philip G; Ricke, Steven C; O'Bryan, Corliss A; Parrish, Nicole M

2012-01-01

We evaluated the in vitro activity of citrus oils against Mycobacterium tuberculosis and other non-tuberculous Mycobacterium species. Citrus essential oils were tested against a variety of Mycobacterium species and strains using the BACTEC radiometric growth system. Cold pressed terpeneless Valencia oil (CPT) was further tested using the Wayne model of in vitro latency. Exposure of M. tuberculosis and M. bovis BCG to 0.025 % cold pressed terpeneless Valencia orange oil (CPT) resulted in a 3-log decrease in viable counts versus corresponding controls. Inhibition of various clinical isolates of the M. avium complex and M. abscessus ranged from 2.5 to 5.2-logs. Some species/strains were completely inhibited in the presence of CPT including one isolate each of the following: the M. avium complex, M. chelonae and M. avium subsp. paratuberculosis. CPT also inhibited the growth of BCG more than 99 % in an in vitro model of latency which mimics anaerobic dormancy thought to occur in vivo. The activity of CPT against drug-resistant strains of the M. avium complex and M. abscessus suggest that the mechanism of action for CPT is different than that of currently available drugs. Inhibition of latently adapted bacilli offers promise for treatment of latent infections of MTB. These results suggest that the antimycobacterial properties of CPT warrant further study to elucidate the specific mechanism of action and clarify the spectrum of activity.

Spatial Distribution and Sampling Plans With Fixed Level of Precision for Citrus Aphids (Hom., Aphididae) on Two Orange Species.

PubMed

Kafeshani, Farzaneh Alizadeh; Rajabpour, Ali; Aghajanzadeh, Sirous; Gholamian, Esmaeil; Farkhari, Mohammad

2018-04-02

Aphis spiraecola Patch, Aphis gossypii Glover, and Toxoptera aurantii Boyer de Fonscolombe are three important aphid pests of citrus orchards. In this study, spatial distributions of the aphids on two orange species, Satsuma mandarin and Thomson navel, were evaluated using Taylor's power law and Iwao's patchiness. In addition, a fixed-precision sequential sampling plant was developed for each species on the host plant by Green's model at precision levels of 0.25 and 0.1. The results revealed that spatial distribution parameters and therefore the sampling plan were significantly different according to aphid and host plant species. Taylor's power law provides a better fit for the data than Iwao's patchiness regression. Except T. aurantii on Thomson navel orange, spatial distribution patterns of the aphids were aggregative on both citrus. T. aurantii had regular dispersion pattern on Thomson navel orange. Optimum sample size of the aphids varied from 30-2061 and 1-1622 shoots on Satsuma mandarin and Thomson navel orange based on aphid species and desired precision level. Calculated stop lines of the aphid species on Satsuma mandarin and Thomson navel orange ranged from 0.48 to 19 and 0.19 to 80.4 aphids per 24 shoots according to aphid species and desired precision level. The performance of the sampling plan was validated by resampling analysis using resampling for validation of sampling plans (RVSP) software. This sampling program is useful for IPM program of the aphids in citrus orchards.

Comparative toxicity of an acetogenin-based extract and commercial pesticides against citrus red mite.

PubMed

Ribeiro, Leandro do Prado; Zanardi, Odimar Zanuzo; Vendramim, José Djair; Yamamoto, Pedro Takao

2014-01-01

Acetogenins, a class of natural compounds produced by some Annonaceae species, are potent inhibitors of mitochondrial electron transport systems. Although the cellular respiration processes are an important biochemical site for the acaricidal action of compounds, few studies have been performed to assess the bioactivity of acetogenin-based biopesticides on spider mites, mainly against species that occur in orchards. Using residual contact bioassays, this study aimed to evaluate the bioactivity of an ethanolic extract from Annona mucosa seeds (ESAM) (Annonaceae) against the citrus red mite Panonychus citri (McGregor) (Acari: Tetranychidae), an important pest of the Brazilian citriculture. ESAM is a homemade biopesticide which was previously characterized by its high concentration of acetogenins. It caused both high mortality of P. citri females (LC50 = 7,295, 4,662, 3,463, and 2,608 mg l(-1), after 48, 72, 96, and 120 h of exposure, respectively) and significant oviposition deterrence (EC50 = 3.194,80 mg l(-1)). However, there was no effect on P. citri female fertility (hatching rate). In addition, the ESAM efficacy (in terms of its LC90) was compared with commercial acaricides/insecticides (at its recommended rate) of both natural [Anosom(®) 1 EC (annonin), Derisom(®) 2 EC (karanjin), and Azamax(®) 1.2 EC (azadirachtin + 3-tigloylazadirachtol)] and synthetic origin [Envidor(®) 24 SC (spirodiclofen)]. Based on all of the analyzed variables, the ESAM exhibited levels of activity superior to other botanical commercial acaricides and similar to spirodiclofen. Thus, our results indicate that ESAM may constitute a biorational acaricide for citrus red mite integrated pest management in Brazilian citrus orchards, particularly for local use.

Soil moisture changes in two experimental sites in Eastern Spain. Irrigation versus rainfed orchards under organic farming

NASA Astrophysics Data System (ADS)

Azorin-Molina, Cesar; Vicente-Serrano, Sergio M.; Cerdà, Artemi

2013-04-01

Within the Soil Erosion and Degradation Research Group Experimental Stations, soil moisture is being researched as a key factor of the soil hydrology and soil erosion (Cerdà, 1995; Cerda, 1997; Cerdà 1998). This because under semiarid conditions soil moisture content plays a crucial role for agriculture, forest, groundwater recharge and soil chemistry and scientific improvement is of great interest in agriculture, hydrology and soil sciences. Soil moisture has been seeing as the key factor for plant photosynthesis, respiration and transpiration in orchards (Schneider and Childers, 1941) and plant growth (Veihmeyer and Hendrickson, 1950). Moreover, soil moisture determine the root growth and distribution (Levin et al., 1979) and the soil respiration ( Velerie and Orchard, 1983). Water content is expressed as a ratio, ranging from 0 (dry) to the value of soil porosity at saturation (wet). In this study we present 1-year of soil moisture measurements at two experimental sites in the Valencia region, Eastern Spain: one representing rainfed orchard typical from the Mediterranean mountains (El Teularet-Sierra de Enguera), and a second site corresponding to an irrigated orange crop (Alcoleja). The EC-5 soil moisture smart sensor S-SMC-M005 integrated with the field-proven ECH2O™ Sensor and a 12-bit A/D has been choosen for measuring soil water content providing ±3% accuracy in typical soil conditions. Soil moisture measurements were carried out at 5-minute intervals from January till December 2012. In addition, soil moisture was measured at two depths in each landscape: 2 and 20 cm depth - in order to retrieve a representative vertical cross-section of soil moisture. Readings are provided directly from 0 (dry) to 0.450 m3/m3 (wet) volumetric water content. The soil moisture smart sensor is conected to a HOBO U30 Station - GSM-TCP which also stored 5-minute temperature, relative humidity, dew point, global solar radiation, precipitation, wind speed and wind direction

Comparison of carotenoid accumulation and biosynthetic gene expression between Valencia and Rohde Red Valencia sweet oranges

USDA-ARS?s Scientific Manuscript database

Carotenoid accumulation and biosynthetic gene expression levels during fruit maturation were compared between ordinary Valencia (VAL) and its more deeply colored mutant Rohde Red Valencia orange (RRV). The two cultivars exhibited different carotenoid profiles and regulatory mechanisms in flavedo and...

A model for Huanglongbing spread between citrus plants including delay times and human intervention

NASA Astrophysics Data System (ADS)

Vilamiu, Raphael G. d'A.; Ternes, Sonia; Braga, Guilherme A.; Laranjeira, Francisco F.

2012-09-01

The objective of this work was to present a compartmental deterministic mathematical model for representing the dynamics of HLB disease in a citrus orchard, including delay in the disease's incubation phase in the plants, and a delay period on the nymphal stage of Diaphorina citri, the most important HLB insect vector in Brazil. Numerical simulations were performed to assess the possible impacts of human detection efficiency of symptomatic plants, as well as the influence of a long incubation period of HLB in the plant.

Monitoring crop coefficient of orange orchards using energy balance and the remote sensed NDVI

NASA Astrophysics Data System (ADS)

Consoli, Simona; Cirelli, Giuseppe Luigi; Toscano, Attilio

2006-09-01

The structure of vegetation is paramount in regulating the exchange of mass and energy across the biosphereatmosphere interface. In particular, changes in vegetation density affected the partitioning of incoming solar energy into sensible and latent heat fluxes that may result in persistent drought through reductions in agricultural productivity and in the water resources availability. Limited research with citrus orchards has shown improvements to irrigation scheduling due to better water-use estimation and more appropriate timing of irrigation when crop coefficient (Kc) estimate, derived from remotely sensed multispectral vegetation indices (VIs), are incorporated into irrigation-scheduling algorithms. The purpose of this article is the application of an empirical reflectance-based model for the estimation of Kc and evapotranspiration fluxes (ET) using ground observations on climatic data and high-resolution VIs from ASTER TERRA satellite imagery. The remote sensed Kc data were used in developing the relationship with the normalized difference vegetation index (NDVI) for orange orchards during summer periods. Validation of remote sensed data on ET, Kc and vegetation features was deal through ground data observations and the resolution of the energy balance to derive latent heat flux density (λE), using measures of net radiation (Rn) and soil heat flux density (G) and estimate of sensible heat flux density (H) from high frequency temperature measurements (Surface Renewal technique). The chosen case study is that of an irrigation area covered by orange orchards located in Eastern Sicily, Italy) during the irrigation seasons 2005 and 2006.

Development of multiplex polymerase chain reaction assay for simultaneous detection of clostero-, badna- and mandari-viruses along with huanglongbing bacterium in citrus trees.

PubMed

Meena, Ram Prasnna; Baranwal, V K

2016-09-01

Citrus trees harbor a large number of viral and bacterial pathogens. Citrus yellow vein clearing virus (CYVCV), Indian citrus ringspot virus (ICRSV), Citrus yellow mosaic virus (CYMV), Citrus tristeza virus (CTV) and a bacterium, Candidatus Liberibacter asiaticus (CLa) associated with huanglongbing (HLB) disease, the most prevalent pathogens in citrus orchards of different regions in India and are responsible for debilitating citriculture. For detection of these viral and bacterial pathogens a quick, sensitive and cost effective detection method is required. With this objective a multiplex polymerase chain reaction (mPCR) assay was developed for simultaneous detection of four viruses and a bacterium in citrus. Several sets of primers were designed for each virus based on the retrieved reference sequences from the GenBank. A primer pair published previously was used for greening bacterium. Each pair of primers was evaluated for their sensitivity and differentiation by simplex and mPCR. The constant amplified products were identified on the basis of molecular size in mPCR and were compared with standard PCR. The amplicons were cloned and results were confirmed with sequencing analysis. The mPCR assay was validated using naturally infected field samples for one or more citrus viruses and the huanglongbing bacterium. The mPCR assay developed here will aid in the production of virus free planting materials and rapid indexing for certification of citrus budwood programme. Copyright © 2016 Elsevier B.V. All rights reserved.

Field performance of transgenic citrus trees: assessment of the long-term expression of uidA and nptII transgenes and its impact on relevant agronomic and phenotypic characteristics.

PubMed

Pons, Elsa; Peris, Josep E; Peña, Leandro

2012-07-15

The future of genetic transformation as a tool for the improvement of fruit trees depends on the development of proper systems for the assessment of unintended effects in field-grown GM lines. In this study, we used eight transgenic lines of two different citrus types (sweet orange and citrange) transformed with the marker genes β-glucuronidase (uidA) and neomycin phosphotransferase II (nptII) as model systems to study for the first time in citrus the long-term stability of transgene expression and whether transgene-derived pleiotropic effects occur with regard to the morphology, development and fruit quality of orchard-grown GM citrus trees. The stability of the integration and expression of the transgenes was confirmed in 7-year-old, orchard-grown transgenic lines by Southern blot analysis and enzymatic assays (GUS and ELISA NPTII), respectively. Little seasonal variation was detected in the expression levels between plants of the same transgenic line in different organs and over the 3 years of analysis, confirming the absence of rearrangements and/or silencing of the transgenes after transferring the plants to field conditions. Comparisons between the GM citrus lines with their non-GM counterparts across the study years showed that the expression of these transgenes did not cause alterations of the main phenotypic and agronomic plant and fruit characteristics. However, when comparisons were performed between diploid and tetraploid transgenic citrange trees and/or between juvenile and mature transgenic sweet orange trees, significant and consistent differences were detected, indicating that factors other than their transgenic nature induced a much higher phenotypic variability. Our results indicate that transgene expression in GM citrus remains stable during long-term agricultural cultivation, without causing unexpected effects on crop characteristics. This study also shows that the transgenic citrus trees expressing the selectable marker genes that are most

Field performance of transgenic citrus trees: Assessment of the long-term expression of uidA and nptII transgenes and its impact on relevant agronomic and phenotypic characteristics

PubMed Central

2012-01-01

Background The future of genetic transformation as a tool for the improvement of fruit trees depends on the development of proper systems for the assessment of unintended effects in field-grown GM lines. In this study, we used eight transgenic lines of two different citrus types (sweet orange and citrange) transformed with the marker genes β-glucuronidase (uidA) and neomycin phosphotransferase II (nptII) as model systems to study for the first time in citrus the long-term stability of transgene expression and whether transgene-derived pleiotropic effects occur with regard to the morphology, development and fruit quality of orchard-grown GM citrus trees. Results The stability of the integration and expression of the transgenes was confirmed in 7-year-old, orchard-grown transgenic lines by Southern blot analysis and enzymatic assays (GUS and ELISA NPTII), respectively. Little seasonal variation was detected in the expression levels between plants of the same transgenic line in different organs and over the 3 years of analysis, confirming the absence of rearrangements and/or silencing of the transgenes after transferring the plants to field conditions. Comparisons between the GM citrus lines with their non-GM counterparts across the study years showed that the expression of these transgenes did not cause alterations of the main phenotypic and agronomic plant and fruit characteristics. However, when comparisons were performed between diploid and tetraploid transgenic citrange trees and/or between juvenile and mature transgenic sweet orange trees, significant and consistent differences were detected, indicating that factors other than their transgenic nature induced a much higher phenotypic variability. Conclusions Our results indicate that transgene expression in GM citrus remains stable during long-term agricultural cultivation, without causing unexpected effects on crop characteristics. This study also shows that the transgenic citrus trees expressing the

Sugar Regulation of Plastid Interconversions in Epicarp of Citrus Fruit 1

PubMed Central

Huff, Albert

1984-01-01

Seasonal transformations between chloroplasts and chromoplasts, as measured by changes in chlorophyll content, in the epicarp of degreening and regreening Citrus sinensis (L.) Osbeck cv Valencia fruit closely parallelled the accumulation and later loss of soluble sugars. At any stage of development, reversing the relative soluble sugar content in the epicarp by culturing pericarp segments on agar media with low (15 millimolar) or high (150 millimolar) sucrose concentrations reversed the direction of change in chlorophyll content. Fruit of C. madurensis Lour., which mature year around and do not regreen, also accumulated soluble sugars in the pericarp as degreening was initiated. The epicarp of C. sinensis fruit accumulated nitrogen, but total nitrogen concentrations and amino acid concentrations changed little, during degreening and regreening of C. sinensis fruit. Cessation of nitrogen fertilization reduced the tendency of pericarp segments to regreen in vitro during subsequent years, but regreening tendency was restored by inclusion of KNO3 in the media. It is concluded that chloroplasts become chromoplasts and citrus fruit degreen partially in response to the accumulation of sugars in the epicarp and that the reverse transformation accompanying regreening of certain citrus species occurs when accumulated sugars disappear. Change in nitrogen flux to the fruit is probably not a factor in regulating seasonal transformations, but an abundance of nitrogen in the epicarp diminishes the effects of high sugar concentrations in inducing transformation of chloroplasts to chromoplasts, thereby retarding degreening and promoting regreening. PMID:16663837

Citrus Tissue Culture 1

PubMed Central

Einset, John W.; Lyon, J. Lorene; Sipes, Deborah L.

1981-01-01

An in vitro bioassay for chemicals that affect Citrus abscission was used to identify three inhibitors of stylar abscission in lemon pistil explants incubated on defined nutrient media. The three inhibitors (picloram, 4-chlorophenoxyacetic acid, and 3,5,6-trichloropyridine-2-oxyacetic acid) are all auxins, and the most potent of them (i.e. picloram) was found to be at least 10 times more active in the bioassay than 2,4-dichlorophenoxyacetic acid. Picloram (2 micromolar) also was shown to be effective in inhibiting stylar abscission in pistil explants from other Citrus cultivars such as mandarin, Valencia, and Washington navel oranges and grapefruit. To study the physiology of auxins active as abscission inhibitors versus inactive auxins in lemon pistils, the transport and metabolism of [1-14C]-2,4-dichlorophenoxyacetic acid was compared with that of [2-14C]indole-3-acetic acid, which is without effect in the bioassay over the range from 0.1-100 micromolar. Insignificant quantities of labeled indole-3-acetic acid and/or labeled derivatives were found to reach the presumptive zone of stylar abscission under the test conditions. Labeled 2,4-dichlorophenoxyacetic acid and/or labeled derivatives also were transported slowly through pistils, but some radioactivity could be detected in the stylar abscission zone as early as 24 hours after the start of incubation. Extensive conversion of [2-14C]indole-3-acetic acid to labeled compounds tentatively considered to be glycoside and cellulosic glucan derivatives was found with the use of solvent extraction methodology. A significantly smaller percentage of the radioactivity in pistils incubated on [1-14C]-2,4-dichlorophenoxyacetic acid was found in fractions corresponding to these derivatives. Both transport and metabolism appear to be important factors affecting the activity of auxins as abscission inhibitors in the bioassay. PMID:16661819

Orchard Business Management. Unit I. Establishing an Orchard Record Keeping System.

ERIC Educational Resources Information Center

Mullinix, Shauna K.

This guide is intended for use in providing in-depth formal classroom and on-site instruction in the principles of business and financial management as they apply to operating and managing orchards. Designed to be used with an accompanying Orchard Business Management Record Book, this unit (i.e., the first year) of the course deals with…

Natural Occurrence of Aldol Condensation Products in Valencia Orange Oil.

PubMed

Abreu, Ingo; Da Costa, Neil C; van Es, Alfred; Kim, Jung-A; Parasar, Uma; Poulsen, Mauricio L

2017-12-01

Cold pressed orange oils contain predominantly d-limonene (approximately 95%) and various other lower concentration monoterpenes, sesquiterpenes, sinensals plus 3 key aliphatic aldehydes: hexanal, octanal. and decanal. The aldol self-condensation products or "dimers" for each aldehyde have been postulated as being present at low concentrations in the oil. However, to date only the hexanal dimer has been previously reported. In this paper, cold pressed Valencia orange oil was fractionally distilled/folded and analyzed by GC and high resolution GC-MS to detect these compounds on 2 different capillary column phases. Subsequently the hexanal, octanal, and decanal self-aldol condensation products, 2-butyl-2-octenal, 2-hexyl-2-decenal, and 2-octyl-2-dodecenal, respectively, were detected in the folded oil. These predominantly trans configuration isomeric compounds were synthesized, to confirm them as being present in nature and evaluated organoleptically by a panel of evaluators. To further confirm the mechanism of their formation, the enriched oil was made into a simple beverage to show the effect on the formation of these aldol compounds under acidic conditions. Finally aliphatic aldehydes from hexanal to undecanal were reacted together in various combinatorial pairs to give an additional 33 self and mixed aldol condensation products, some of which were also detected in the folded oil. This paper discloses the structural elucidation and synthesis of 8 novel aldol condensation products found at trace concentrations in citrus and leading to a further 31 mass spectrally determined aldol products. Sensory evaluations and application of some of these components were demonstrated in a model citrus beverage. © 2017 Institute of Food Technologists®.

One Target, Two Mechanisms: The Impact of 'Candidatus Liberibacter asiaticus' and Its Vector, Diaphorina citri, on Citrus Leaf Pigments.

PubMed

Killiny, Nabil; Nehela, Yasser

2017-07-01

Huanglongbing (HLB) is currently the largest threat to global citrus production. We examined the effect of HLB pathogen 'Candidatus Liberibacter asiaticus' infection or infestation by its vector, Diaphorina citri, on 'Valencia' sweet orange leaf pigments using high-performance liquid chromatography, followed by gene expression analysis for 46 involved genes in carotenoid and chlorophyll biosynthesis pathways. Both 'Ca. L. asiaticus' and D. citri alter the total citrus leaf pigment balance with a greater impact by 'Ca. L. asiaticus'. Although zeaxanthin was accumulated in 'Ca. L. asiaticus'-infected leaves, chlorophyllide a was increased in D. citri-infested plants. Our findings support the idea that both 'Ca. L. asiaticus' and D. citri affect the citrus pigments and promote symptom development but using two different mechanisms. 'Ca. L. asiaticus' promotes chlorophyll degradation but accelerates the biosynthesis of carotenoid pigments, resulting in accumulation of abscisic acid and its precursor, zeaxanthin. Zeaxanthin also has a photoprotective role. By contrast, D. citri induced the degradation of most carotenoids and accelerated chlorophyll biosynthesis, leading to chlorophyllide a accumulation. Chlorophyllide a might have an antiherbivory role. Accordingly, we suggest that citrus plants try to defend themselves against 'Ca. L. asiaticus' or D. citri using multifaceted defense systems, based on the stressor type. These findings will help in better understanding the tritrophic interactions among plant, pathogen, and vector.

Juice volatile composition differences between Valencia orange and its mutant Rohde Red Valencia are associated with carotenoid profile differences

USDA-ARS?s Scientific Manuscript database

A targeted approach using HS-SPME-GC–MS was performed to investigate volatile compounds of ordinary Valencia (VAL) and its more deeply colored mutant Rohde Red Valencia orange (RRV) at different developmental stages. Fifty-six volatile components classified into six chemical groups were quantified. ...

Orchard Business Management. Unit II. Management and Analysis of the Orchard Operation.

ERIC Educational Resources Information Center

Mullinix, Shauna K.

This guide is intended for use in providing in-depth formal classroom and on-site instruction in the principles of business and financial management as they apply to operating and managing orchards. Designed to be used with an accompanying Orchard Business Management Record Book, this unit is devoted to management and analysis of an orchard…

Flower production on clonal orchards at Oconto River Seed Orchard in Wisconsin

Treesearch

J.G. Murphy; R.G. Miller

1977-01-01

The Eastern Region, USDA Forest Service has been establishing and managing seed orchards to produce improved seed for the National Forests in the Lake States since 1969. This paper presents a review of the female flower production for the past 4 years in the white pine, white spruce, and black spruce clonal seed orchards.

Population structure and diversity of citrus tristeza virus (CTV) isolates in Hunan province, China.

PubMed

Xiao, Cui; Yao, Run-Xian; Li, Fang; Dai, Su-Ming; Licciardello, Grazia; Catara, Antonino; Gentile, Alessandra; Deng, Zi-Niu

2017-02-01

Stem-pitting (SP) is the main type of citrus tristeza virus (CTV) that causes severe damage to citrus trees, especially those of sweet orange, in Hunan province, China. Understanding the local CTV population structure should provide clues for effective mild strain cross-protection (MSCP) of the SP strain of CTV. In this study, markers for the p23 gene, multiple molecular markers (MMMs), and sequence analysis of the three silencing suppressor genes (p20, p23 and p25) were employed to analyze the genetic diversity and genotype composition of the CTV population based on 51 CTV-positive samples collected from 14 citrus orchards scattered around six major citrus-growing areas of Hunan. The results indicated that the CTV population structure was extremely complex and that infection was highly mixed. In total, p23 gene markers resulted in six profiles, and MMMs demonstrated 25 profiles. The severe VT and T3 types appeared to be predominantly associated with SP, while the mild T30 and RB types were related to asymptomatic samples. Based on phylogenetic analysis of the amino acid sequences of p20, p23 and p25, 19 representative CTV samples were classified into seven recently established CTV groups and a potentially novel one. A high level of genetic diversity, as well as potential recombination, was revealed among different CTV isolates. Five pure SP severe and two pure mild strains were identified by genotype composition analysis. Taken together, the results update the genetic diversity of CTV in Hunan with the detection of one possible novel strain, and this information might be applicable for the selection of appropriate mild CTV strains for controlling citrus SP disease through cross-protection.

GUS expression in sweet oranges (Citrus sinensis L. Osbeck) driven by three different phloem-specific promoters.

PubMed

Miyata, Luzia Yuriko; Harakava, Ricardo; Stipp, Liliane Cristina Libório; Mendes, Beatriz Madalena Januzzi; Appezzato-da-Glória, Beatriz; de Assis Alves Mourão Filho, Francisco

2012-11-01

Huanglongbing (HLB) is associated with Candidatus Liberibacter spp., endogenous, sieve tube-restricted bacteria that are transmitted by citrus psyllid insect vectors. Transgenic expression in the phloem of specific genes that might affect Ca. Liberibacter spp. growth and development may be an adequate strategy to improve citrus resistance to HLB. To study specific phloem gene expression in citrus, we developed three different binary vector constructs with expression cassettes bearing the β-glucuronidase (GUS) reporter gene (uidA) under the control of one of the three different promoters: Citrus phloem protein 2 (CsPP2), Arabidopsis thaliana phloem protein 2 (AtPP2), and Arabidopsis thaliana sucrose transporter 2 (AtSUC2). Transgenic lines of 'Hamlin', 'Pera', and 'Valencia' sweet oranges [Citrus sinensis (L.) Osbeck] were produced via Agrobacterium tumefaciens transformation. The epicotyl segments collected from in vitro germinated seedlings were used as explants. The gene nptII, which confers resistance to the antibiotic kanamycin, was used for selection. The transformation efficiency was expressed as the number of GUS-positive shoots over the total number of explants and varied from 1.54 to 6.08 % among the three cultivars and three constructs studied. Several lines of the three sweet orange cultivars analyzed using PCR and Southern blot analysis were genetically transformed with the three constructs evaluated. The histological GUS activity in the leaves indicates that the uidA gene was preferentially expressed in the phloem, which suggests that the use of the three promoters might be adequate for producing HLB-resistant transgenic sweet oranges. The results reported here conclusively demonstrate the preferential expression of GUS in the phloem driven by two heterologous and one homologous gene promoters. Key message The results reported here conclusively demonstrate the preferential expression of GUS in the phloem driven by two heterologous and one homologous

Effect of Liberibacter infection (huanglongbing or "greening" disease) of citrus on orange juice flavor quality by sensory evaluation.

PubMed

Plotto, Anne; Baldwin, Elizabeth; McCollum, Greg; Manthey, John; Narciso, Jan; Irey, Mike

2010-05-01

Some anecdotal reports suggest that infection of citrus trees with Candidatus Liberibacter asiaticus (Las), the suspected causal agent of huanglongbing (HLB) disease, imparts off flavor to orange juice. It is of interest to the industry to know how Las infection affects juice quality with respect to cultivar, maturity, or processing method. Hamlin, Midsweet, and Valencia oranges were harvested over 2 y from trees that tested negative (Las-) or positive (Las+) for Las from different groves and included normal looking (nonsymptomatic) and symptomatic fruit (small, green, and lopsided) from Las+ trees. In the 1st year, fruit were manually juiced, while in the 2nd year, a commercial process was used. Juice from Las+ trees was compared to juice from Las- trees in difference-from-control tests, and by descriptive analysis. Results showed large variability due to tree, harvest date, and cultivar. Juice from Hamlin Las+ trees tended to be more bitter and sour than its Las- counterpart. In contrast, hand processed Valencia juice from Las+ trees was perceived to have some off-flavor and bitterness compared to control, but the following year, commercially processed Valencia juice from Las+ trees was perceived to be only slightly more sour than juice from Las- trees for the April harvest, and to be sweeter for the June harvest. When juice from individual replicates was pooled to be more representative of a commercial situation, there was no difference between Las+ and Las- juice in Valencia. Trained panel differences were noted for juice from Hamlin Las+ fruit, especially for symptomatic fruit. Assumptions that juice made from oranges harvested from Huanglongbing (from infection with Liberibacter sp.) affected trees is off-flavored appeared to be generally more true for Hamlin juice than for Midsweet or Valencia, especially for Hamlin juice made from symptomatic fruit. For Midsweet and Valencia, flavor differences between juice made from fruit harvested from diseased or

Role of two insect growth regulators in integrated pest management of citrus scales.

PubMed

Grafton-Cardwell, E E; Lee, J E; Stewart, J R; Olsen, K D

2006-06-01

Portions of two commercial citrus orchards were treated for two consecutive years with buprofezin or three consecutive years with pyriproxyfen in a replicated plot design to determine the long-term impact of these insect growth regulators (IGRs) on the San Joaquin Valley California integrated pest management program. Pyriproxyfen reduced the target pest, California red scale, Aonidiella aurantii Maskell, to nondetectable levels on leaf samples approximately 4 mo after treatment. Pyriproxyfen treatments reduced the California red scale parasitoid Aphytis melinus DeBach to a greater extent than the parasitoid Comperiella bifasciata Howard collected on sticky cards. Treatments of lemons Citrus limon (L.) Burm. f. infested with scale parasitized by A. melinus showed only 33% direct mortality of the parasitoid, suggesting the population reduction observed on sticky cards was due to low host density. Three years of pyriproxyfen treatments did not maintain citricola scale, Coccus pseudomagnoliarum (Kuwana), below the treatment threshold and cottony cushion scale, Icerya purchasi Maskell, was slowly but incompletely controlled. Buprofezin reduced California red scale to very low but detectable levels approximately 5 mo after treatment. Buprofezin treatments resulted in similar levels of reduction of the two parasitoids A. melinus and C. bifasciata collected on sticky cards. Treatments of lemons infested with scale parasitized by A. melinus showed only 7% mortality of the parasitoids, suggesting the population reduction observed on sticky cards was due to low host density. Citricola scale was not present in this orchard, and cottony cushion scale was slowly and incompletely controlled by buprofezin. These field plots demonstrated that IGRs can act as organophosphate insecticide replacements for California red scale control; however, their narrower spectrum of activity and disruption of coccinellid beetles can allow other scale species to attain primary pest status.

POEM: PESTICIDE ORCHARD ECOSYSTEM MODEL

EPA Science Inventory

The Pesticide Orchard Ecosystem Model (POEM) is a mathematical model of organophosphate pesticide movement in an apple orchard ecosystem. In addition submodels on invertebrate population dynamics are included. The fate model allows the user to select the pesticide, its applicatio...

7 CFR 301.76-3 - Quarantined areas; citrus greening and Asian citrus psyllid.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 5 2013-01-01 2013-01-01 false Quarantined areas; citrus greening and Asian citrus... Greening and Asian Citrus Psyllid § 301.76-3 Quarantined areas; citrus greening and Asian citrus psyllid... quarantined area for Asian citrus psyllid in accordance with the criteria listed in paragraph (c) of this...

7 CFR 301.76-3 - Quarantined areas; citrus greening and Asian citrus psyllid.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Quarantined areas; citrus greening and Asian citrus... Greening and Asian Citrus Psyllid § 301.76-3 Quarantined areas; citrus greening and Asian citrus psyllid... quarantined area for Asian citrus psyllid in accordance with the criteria listed in paragraph (c) of this...

7 CFR 301.76-3 - Quarantined areas; citrus greening and Asian citrus psyllid.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 5 2012-01-01 2012-01-01 false Quarantined areas; citrus greening and Asian citrus... Greening and Asian Citrus Psyllid § 301.76-3 Quarantined areas; citrus greening and Asian citrus psyllid... quarantined area for Asian citrus psyllid in accordance with the criteria listed in paragraph (c) of this...

7 CFR 301.76-3 - Quarantined areas; citrus greening and Asian citrus psyllid.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 5 2014-01-01 2014-01-01 false Quarantined areas; citrus greening and Asian citrus... Greening and Asian Citrus Psyllid § 301.76-3 Quarantined areas; citrus greening and Asian citrus psyllid... quarantined area for Asian citrus psyllid in accordance with the criteria listed in paragraph (c) of this...

Cover crops impact on excess rainfall and soil erosion rates in orchards and potato fields, Israel

NASA Astrophysics Data System (ADS)

Egozi, Roey; Gil, Eshel

2015-04-01

Bare soil and high drainage densities are common characteristics of intensive agriculture land. The couplings of these characteristics lead to high runoff and eroded soil volumes leaving the field or the orchard via the local drainage system into the fluvial system. This process increase flood risk due to massive deposition of the coarse fraction of the eroded soil and therefore reduces channel capacity to discharge the increase volumes of concentrated runoff. As a result drainage basin authorities are forced to invest large amount of money in maintaining and enlarging the drainage network. However this approach is un-sustainable. On the other hand, implementing cover crops (CC) and modification to current agricultural practices over the contributing area of the watershed seems to have more benefits and provide sustainable solution. A multi-disciplinary approach applied in commercial potatoes fields and orchards that utilize the benefit of CC shows great success as means of soil and water conservation and weed disinfestation without reduction in the yield, its quality or its profitability. The results indicate that it is possible to grow potatoes and citrus trees under CC with no reduction in yield or nutrient uptake, with more than 95% reduction in soil loss and more than 60% in runoff volumes and peak discharges.

Citrus Genomics

PubMed Central

Talon, Manuel; Gmitter Jr., Fred G.

2008-01-01

Citrus is one of the most widespread fruit crops globally, with great economic and health value. It is among the most difficult plants to improve through traditional breeding approaches. Currently, there is risk of devastation by diseases threatening to limit production and future availability to the human population. As technologies rapidly advance in genomic science, they are quickly adapted to address the biological challenges of the citrus plant system and the world's industries. The historical developments of linkage mapping, markers and breeding, EST projects, physical mapping, an international citrus genome sequencing project, and critical functional analysis are described. Despite the challenges of working with citrus, there has been substantial progress. Citrus researchers engaged in international collaborations provide optimism about future productivity and contributions to the benefit of citrus industries worldwide and to the human population who can rely on future widespread availability of this health-promoting and aesthetically pleasing fruit crop. PMID:18509486

The diversity of citrus endophytic bacteria and their interactions with Xylella fastidiosa and host plants.

PubMed

Azevedo, João Lúcio; Araújo, Welington Luiz; Lacava, Paulo Teixeira

2016-01-01

The bacterium Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC) and has been associated with important losses in commercial orchards of all sweet orange [Citrus sinensis (L.)] cultivars. The development of this disease depends on the environmental conditions, including the endophytic microbial community associated with the host plant. Previous studies have shown that X. fastidiosa interacts with the endophytic community in xylem vessels as well as in the insect vector, resulting in a lower bacterial population and reduced CVC symptoms. The citrus endophytic bacterium Methylobacterium mesophilicum can trigger X. fastidiosa response in vitro, which results in reduced growth and induction of genes associated with energy production, stress, transport, and motility, indicating that X. fastidiosa has an adaptive response to M. mesophilicum. Although this response may result in reduced CVC symptoms, the colonization rate of the endophytic bacteria should be considered in studies that intend to use this endophyte to suppress CVC disease. Symbiotic control is a new strategy that uses symbiotic endophytes as biological control agents to antagonize or displace pathogens. Candidate endophytes for symbiotic control of CVC must occupy the xylem of host plants and attach to the precibarium of sharpshooter insects to access the pathogen. In the present review, we focus on interactions between endophytic bacteria from sweet orange plants and X. fastidiosa, especially those that may be candidates for control of CVC.

The diversity of citrus endophytic bacteria and their interactions with Xylella fastidiosa and host plants

PubMed Central

Azevedo, João Lúcio; Araújo, Welington Luiz; Lacava, Paulo Teixeira

2016-01-01

Abstract The bacterium Xylella fastidiosa is the causal agent of citrus variegated chlorosis (CVC) and has been associated with important losses in commercial orchards of all sweet orange [Citrus sinensis (L.)] cultivars. The development of this disease depends on the environmental conditions, including the endophytic microbial community associated with the host plant. Previous studies have shown that X. fastidiosa interacts with the endophytic community in xylem vessels as well as in the insect vector, resulting in a lower bacterial population and reduced CVC symptoms. The citrus endophytic bacterium Methylobacterium mesophilicum can trigger X. fastidiosa response in vitro, which results in reduced growth and induction of genes associated with energy production, stress, transport, and motility, indicating that X. fastidiosa has an adaptive response to M. mesophilicum. Although this response may result in reduced CVC symptoms, the colonization rate of the endophytic bacteria should be considered in studies that intend to use this endophyte to suppress CVC disease. Symbiotic control is a new strategy that uses symbiotic endophytes as biological control agents to antagonize or displace pathogens. Candidate endophytes for symbiotic control of CVC must occupy the xylem of host plants and attach to the precibarium of sharpshooter insects to access the pathogen. In the present review, we focus on interactions between endophytic bacteria from sweet orange plants and X. fastidiosa, especially those that may be candidates for control of CVC. PMID:27727362

7 CFR 301.76-2 - Regulated articles for Asian citrus psyllid and citrus greening.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Regulated articles for Asian citrus psyllid and citrus... Greening and Asian Citrus Psyllid § 301.76-2 Regulated articles for Asian citrus psyllid and citrus greening. The following are regulated articles for Asian citrus psyllid and citrus greening: (a) All plants...

7 CFR 301.76-2 - Regulated articles for Asian citrus psyllid and citrus greening.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 5 2014-01-01 2014-01-01 false Regulated articles for Asian citrus psyllid and citrus... Greening and Asian Citrus Psyllid § 301.76-2 Regulated articles for Asian citrus psyllid and citrus greening. The following are regulated articles for Asian citrus psyllid and citrus greening: (a) All plants...

7 CFR 301.76-2 - Regulated articles for Asian citrus psyllid and citrus greening.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 5 2012-01-01 2012-01-01 false Regulated articles for Asian citrus psyllid and citrus... Greening and Asian Citrus Psyllid § 301.76-2 Regulated articles for Asian citrus psyllid and citrus greening. The following are regulated articles for Asian citrus psyllid and citrus greening: (a) All plants...

7 CFR 301.76-2 - Regulated articles for Asian citrus psyllid and citrus greening.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 5 2013-01-01 2013-01-01 false Regulated articles for Asian citrus psyllid and citrus... Greening and Asian Citrus Psyllid § 301.76-2 Regulated articles for Asian citrus psyllid and citrus greening. The following are regulated articles for Asian citrus psyllid and citrus greening: (a) All plants...

Pseudomonas caspiana sp. nov., a citrus pathogen in the Pseudomonas syringae phylogenetic group.

PubMed

Busquets, Antonio; Gomila, Margarita; Beiki, Farid; Mulet, Magdalena; Rahimian, Heshmat; García-Valdés, Elena; Lalucat, Jorge

2017-07-01

In a screening by multilocus sequence analysis of Pseudomonas strains isolated from diverse origins, 4 phylogenetically closely related strains (FBF58, FBF102 T , FBF103, and FBF122) formed a well-defined cluster in the Pseudomonas syringae phylogenetic group. The strains were isolated from citrus orchards in northern Iran with disease symptoms in the leaves and stems and its pathogenicity against citrus plants was demonstrated. The whole genome of the type strain of the proposed new species (FBF102 T =CECT 9164 T =CCUG 69273 T ) was sequenced and characterized. Comparative genomics with the 14 known Pseudomonas species type strains of the P. syringae phylogenetic group demonstrated that this strain belonged to a new genomic species, different from the species described thus far. Genome analysis detected genes predicted to be involved in pathogenesis, such as an atypical type 3 secretion system and two type 6 secretion systems, together with effectors and virulence factors. A polyphasic taxonomic characterization demonstrated that the 4 plant pathogenic strains represented a new species, for which the name Pseudomonas caspiana sp. nov. is proposed. Copyright © 2017 Elsevier GmbH. All rights reserved.

Economic and Highly Effective Trap-Lure Combination to Monitor the Mexican Fruit Fly (Diptera: Tephritidae) at the Orchard Level.

PubMed

Lasa, R; Herrera, F; Miranda, E; Gómez, E; Antonio, S; Aluja, M

2015-08-01

Monitoring population levels of the Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae), at the orchard level prior and during the fruit ripening period can result in significant savings in the costs of managing this pestiferous insect. Unfortunately, to date, no highly effective and economically viable trap is available to growers. To move toward this goal, trap-lure combinations were evaluated in trials performed in citrus orchards in Veracruz, Mexico. CeraTrap, an enzymatic hydrolyzed protein from pig intestinal mucose, was 3.6 times more attractive to A. ludens than the most commonly used bait of Captor (hydrolyzed protein and borax) when using Multilure traps. When several commercial traps were evaluated, the efficacy of a simple and inexpensive transparent polyethylene (PET) bottle with 10-mm lateral holes was similar to that of the costly Multilure trap when baited with CeraTrap and significantly more effective than a Multilure trap baited with Captor. PET bottles filled with Cera Trap, rebaited at 8-wk intervals, and tested in trials encompassing 72 ha of citrus groves, were significantly more effective than Multilure traps baited with Captor that need to be serviced weekly. In addition to this relevant finding, CeraTrap baited traps detected A. ludens at lower population densities and attracted a significantly higher number of flies at all densities when compared with Captor-baited traps. We conclude that CeraTrap represents a cost-effective and highly efficient bait that will enable us to pursue the goal of developing economic thresholds, a badly needed management tool for A. ludens. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparative toxicity of pesticides in three phytoseiid mites with different life-style occurring in citrus: Euseius stipulatus, Neoseiulus californicus and Phytoseiulus persimilis.

PubMed

Argolo, Poliane Sá; Jacas, Josep A; Urbaneja, Alberto

2014-01-01

Conservation and augmentative biological control strategies have been developed to take full advantage of the natural enemies that occur in Spanish citrus orchards. Among them, the predatory mites Euseius stipulatus, Neoseiulus californicus and Phytoseiulus persimilis play an important role in the biological control of tetranychid mites. However, these predatory mites are often affected by pesticides and information about the side-effects of these products against these beneficial arthropods is essential to guarantee their efficacy. The side-effects of some pesticides remain unknown and the primary aim of this study was to fill this gap. We have further used this information and that collected from other sources to compare the response of these three mite species to pesticides. Based on this information, E. stipulatus has the most tolerant species, followed by N. californicus and P. persimilis. Therefore, using E. stipulatus as an indicator species in citrus may have led to the paradox of selecting presumed selective pesticides resulting in excessive impact on N. californicus and, especially on P. persimilis. Because these two latter species are considered key for the biological control of T. urticae in citrus, especially clementines, in Spain, we propose to use P. persimilis as the relevant indicator of such effects on predacious mites occurring in citrus instead of E. stipulatus. This change could have a dramatic impact on the satisfactory control of tetranychid mites in citrus in the near future.

Exogenous application of the plant signalers methyl jasmonate and salicylic acid induces changes in volatile emissions from citrus foliage and influences the aggregation behavior of Asian citrus psyllid (Diaphorina citri), vector of Huanglongbing.

PubMed

Patt, Joseph M; Robbins, Paul S; Niedz, Randy; McCollum, Greg; Alessandro, Rocco

2018-01-01

Huanglongbing, also known as citrus greening, is a destructive disease that threatens citrus production worldwide. It is putatively caused by the phloem-limited bacterium Candidatus Liberibacter asiaticus (Las). Currently, the disease is untreatable and efforts focus on intensive insecticide use to control the vector, Asian citrus psyllid (Diaphorina citri). Emerging psyllid resistance to multiple insecticides has generated investigations into the use of exogenously applied signaling compounds to enhance citrus resistance to D. citri and Las. In the present study, we examined whether foliar applications of methyl jasmonate (MJ), a volatile signaling compound associated with the induced systemic resistance pathway, and salicylic acid, a constituent of the systemic acquired resistance pathway, would elicit the emission of defense-related volatiles in citrus foliage, and what effect this might have on the host-plant searching behavior of D. citri. Comparisons were made of volatiles emitted from growing shoots of uninfected and Las-infected 'Valencia' sweet orange (Citrus sinensis) trees over two consecutive sampling days. A settling behavioral assay was used to compare psyllid attraction to MJ-treated vs. Tween-treated citrus sprigs. All three main effects, Las infection status, plant signaler application, and sampling day, influenced the proportions of individual volatile compounds emitted in different treatment groups. MJ- and SA-treated trees had higher emission rates than Tween-treated trees. Methyl salicylate (MeSA) and β-caryophyllene were present in higher proportions in the volatiles collected from Las-infected + trees. On the other hand, Las-infected + MJ-treated trees emitted lower proportions of MeSA than did Las-infected + Tween-treated trees. Because MeSA is a key D. citri attractant, this result suggests that MJ application could suppress MeSA emission from Las-infected trees, an approach that could be used to discourage psyllid colonization during

Metabolomic Response to Huanglongbing: Role of Carboxylic Compounds in Citrus sinensis Response to 'Candidatus Liberibacter asiaticus' and Its Vector, Diaphorina citri.

PubMed

Killiny, Nabil; Nehela, Yasser

2017-08-01

Huanglongbing, a destructive disease of citrus, is caused by the fastidious bacterium 'Candidatus Liberibacter asiaticus' and transmitted by Asian citrus psyllid, Diaphorina citri. The impact of 'Ca. L. asiaticus' infection or D. citri infestation on Valencia sweet orange (Citrus sinensis) leaf metabolites was investigated using gas chromatography mass spectrometry, followed by gene expression analysis for 37 genes involved in jasmonic acid (JA), salicylic acid (SA), and proline-glutamine pathways. The total amino acid abundance increased after 'Ca. L. asiaticus' infection, while the total fatty acids increased dramatically after infestation with D. citri, compared with control plants. Seven amino acids (glycine, l-isoleucine, l-phenylalanine, l-proline, l-serine, l-threonine, and l-tryptophan) and five organic acids (benzoic acid, citric acid, fumaric acid, SA, and succinic acid) increased in 'Ca. L. asiaticus'-infected plants. On the other hand, the abundance of trans-JA and its precursor α-linolenic increased in D. citri-infested plants. Surprisingly, the double attack of both D. citri infestation and 'Ca. L. asiaticus' infection moderated the metabolic changes in all chemical classes studied. In addition, the gene expression analysis supported these results. Based on these findings, we suggest that, although amino acids such as phenylalanine are involved in citrus defense against 'Ca. L. asiaticus' infection through the activation of an SA-mediated pathway, fatty acids, especially α-linolenic acid, are involved in defense against D. citri infestation via the induction of a JA-mediated pathway.

Citrus diseases with global ramifications including citrus canker and huanglongbing

USDA-ARS?s Scientific Manuscript database

Although there are a number of diseases that plague citrus production worldwide, two bacterial diseases are particularly problematic. Both are of Asian origin and currently cause severe economic damage: Asiatic citrus canker (ACC) and citrus huanglongbing (HLB). Although ACC has been found in the ...

Spatial and temporal spread of Citrus tristeza virus and its aphid vectors in the North western area of Morocco.

PubMed

Elhaddad, Abdesslam; ElAmrani, Amal; Fereres, Alberto; Moreno, Aranzazu

2016-12-01

First report of Citrus tristeza virus (CTV,Closterovirus) in Morocco datesback to 1961 in collections of citrus varieties. An exhaustive survey of citrus in the north of the country in 2009 revealed that CTV was spread all over the citrus production area. We attempted to evaluate the relative contribution of different aphid species in the spread of CTV disease in a Citrus reticulata orchard at the Loukkous region during 2 years (2012 and 2013). The overall CTV incidence estimated in the experimental site increased from 17.8% in 2012 to 31.15% in 2013. The most abundant aphid species colonising clementine trees was Aphis spiraecola and A. gossypii. Both aphid species reached their maximum peaks during the spring season. The rate of viruliferous aphids, estimated by real-time RT-PCR of single aphid, revealed that 35.4% of winged A. gossypii and 28.8% of winged A. spiraecola were viruliferous, confirming a high inoculum pressure in the area surrounding the experimental site. The aphid species Toxoptera citricida, which is able to transmit the aggressive isolates of CTV, was not found in the Loukkous region. The study of the spatial distribution of the CTV showed that in general, the disease was randomly distributed in the field. Overall, the results seem to indicate that A. spiraecola may be considered as the major aphid species contributing to CTV spread in our experimental conditions. The prevalence of mild strains in the region and the high level of aphid flight activity could explain the rapid evolution of CTV incidence in the experimental area. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Citrus flush shoot ontogeny modulates biotic potential of Diaphorina citri.

PubMed

Cifuentes-Arenas, Juan Camilo; de Goes, António; de Miranda, Marcelo Pedreira; Beattie, George Andrew Charles; Lopes, Silvio Aparecido

2018-01-01

The biology and behaviour of the psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae), the major insect vector of bacteria associated with huanglongbing, have been extensively studied with respect to host preferences, thermal requirements, and responses to visual and chemical volatile stimuli. However, development of the psyllid in relation to the ontogeny of immature citrus flush growth has not been clearly defined or illustrated. Such information is important for determining the timing and frequency of measures used to minimize populations of the psyllid in orchards and spread of HLB. Our objective was to study how flush ontogeny influences the biotic potential of the psyllid. We divided citrus flush growth into six stages within four developmental phases: emergence (V1), development (V2 and V3), maturation (V4 and V5), and dormancy (V6). Diaphorina citri oviposition and nymph development were assessed on all flush stages in a temperature controlled room, and in a screen-house in which ambient temperatures varied. Our results show that biotic potential of Diaphorina citri is not a matter of the size or the age of the flushes (days after budbreak), but the developmental stage within its ontogeny. Females laid eggs on flush V1 to V5 only, with the time needed to commence oviposition increasing with the increasing in flush age. Stages V1, V2 and V3 were most suitable for oviposition, nymph survival and development, and adult emergence, which showed evidence of protandry. Flush shoots at emerging and developmental phases should be the focus of any chemical or biological control strategy to reduce the biotic potential of D. citri, to protect citrus tree from Liberibacter infection and to minimize HLB dissemination.

Citrus flush shoot ontogeny modulates biotic potential of Diaphorina citri

PubMed Central

de Goes, António; de Miranda, Marcelo Pedreira

2018-01-01

The biology and behaviour of the psyllid Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Liviidae), the major insect vector of bacteria associated with huanglongbing, have been extensively studied with respect to host preferences, thermal requirements, and responses to visual and chemical volatile stimuli. However, development of the psyllid in relation to the ontogeny of immature citrus flush growth has not been clearly defined or illustrated. Such information is important for determining the timing and frequency of measures used to minimize populations of the psyllid in orchards and spread of HLB. Our objective was to study how flush ontogeny influences the biotic potential of the psyllid. We divided citrus flush growth into six stages within four developmental phases: emergence (V1), development (V2 and V3), maturation (V4 and V5), and dormancy (V6). Diaphorina citri oviposition and nymph development were assessed on all flush stages in a temperature controlled room, and in a screen-house in which ambient temperatures varied. Our results show that biotic potential of Diaphorina citri is not a matter of the size or the age of the flushes (days after budbreak), but the developmental stage within its ontogeny. Females laid eggs on flush V1 to V5 only, with the time needed to commence oviposition increasing with the increasing in flush age. Stages V1, V2 and V3 were most suitable for oviposition, nymph survival and development, and adult emergence, which showed evidence of protandry. Flush shoots at emerging and developmental phases should be the focus of any chemical or biological control strategy to reduce the biotic potential of D. citri, to protect citrus tree from Liberibacter infection and to minimize HLB dissemination. PMID:29304052

MicroRNA-mediated responses to long-term magnesium-deficiency in Citrus sinensis roots revealed by Illumina sequencing.

PubMed

Liang, Wei-Wei; Huang, Jing-Hao; Li, Chun-Ping; Yang, Lin-Tong; Ye, Xin; Lin, Dan; Chen, Li-Song

2017-08-24

Magnesium (Mg)-deficiency occurs most frequently in strongly acidic, sandy soils. Citrus are grown mainly on acidic and strong acidic soils. Mg-deficiency causes poor fruit quality and low fruit yield in some Citrus orchards. For the first time, we investigated Mg-deficiency-responsive miRNAs in 'Xuegan' (Citrus sinensis) roots using Illumina sequencing in order to obtain some miRNAs presumably responsible for Citrus Mg-deficiency tolerance. We obtained 101 (69) miRNAs with increased (decreased) expression from Mg-starved roots. Our results suggested that the adaptation of Citrus roots to Mg-deficiency was related to the several aspects: (a) inhibiting root respiration and related gene expression via inducing miR158 and miR2919; (b) enhancing antioxidant system by down-regulating related miRNAs (miR780, miR6190, miR1044, miR5261 and miR1151) and the adaptation to low-phosphorus (miR6190); (c) activating transport-related genes by altering the expression of miR6190, miR6485, miR1044, miR5029 and miR3437; (d) elevating protein ubiquitination due to decreased expression levels of miR1044, miR5261, miR1151 and miR5029; (e) maintaining root growth by regulating miR5261, miR6485 and miR158 expression; and (f) triggering DNA repair (transcription regulation) by regulating miR5176 and miR6485 (miR6028, miR6190, miR6485, miR5621, miR160 and miR7708) expression. Mg-deficiency-responsive miRNAs involved in root signal transduction also had functions in Citrus Mg-deficiency tolerance. We obtained several novel Mg-deficiency-responsive miRNAs (i.e., miR5261, miR158, miR6190, miR6485, miR1151 and miR1044) possibly contributing to Mg-deficiency tolerance. These results revealed some novel clues on the miRNA-mediated adaptation to nutrient deficiencies in higher plants.

Integrating ecosystem services into risk management decisions: case study with Spanish citrus and the insecticide chlorpyrifos.

PubMed

Deacon, Samantha; Norman, Steve; Nicolette, Joseph; Reub, Gregory; Greene, Gretchen; Osborn, Rachel; Andrews, Paul

2015-02-01

The European regulatory system for the approval of pesticides includes a thorough evaluation of risks to the environment and is designed to be protective of ecosystems. However, a decision to ban an agrochemical could also potentially have a negative impact on the value of ecosystem services, if resulting changes in crop management are damaging to ecosystems or result in negative socio-economic impacts. To support regulatory decision-making, consideration of ecosystem services to identify best environmental management options could be a way forward. There is generally a growing trend for the consideration of ecosystem services in decision making. Ecosystems provide the conditions for growing food, regulate water and provide wildlife habitats; these, amongst others, are known as ecosystem services. The objectives of this case study were to bring a holistic approach to decision making by valuing the environmental, social and economic benefits derived from the use of chlorpyrifos in Valencian citrus production. Spanish growers harvest between 5 and 6 milliont of citrus annually, worth an estimated €5 to 7 billion in food markets throughout Europe. The approach highlighted the potential for unintended negative consequences of regulatory decisions if the full context is not considered. In this study, rather than a regulatory restriction, the best option was the continued use of chlorpyrifos together with vegetated conservation patches as refuges for non-target insects. The conservation patches offset potential insecticidal impacts to insects whilst maintaining citrus production, farm income and the amenity value of the citrus landscape of Valencia. This was an initial proof-of-concept study and illustrates the importance of a wider perspective; other cases may have different outcomes depending on policies, the pesticide, crop scenarios, farm economics and the region. Copyright © 2014 Elsevier B.V. All rights reserved.

Phylogenetic and Molecular Variability Studies Reveal a New Genetic Clade of Citrus leprosis virus C

PubMed Central

Ramos-González, Pedro Luis; Chabi-Jesus, Camila; Guerra-Peraza, Orlene; Breton, Michèle Claire; Arena, Gabriella Dias; Nunes, Maria Andreia; Kitajima, Elliot Watanabe; Machado, Marcos Antonio; Freitas-Astúa, Juliana

2016-01-01

Citrus leprosis virus C (CiLV-C) causes a severe disease affecting citrus orchards in the Western hemisphere. This study reveals the molecular variability of the virus by analyzing four genomic regions (p29, p15, MP and RNA2-intergenic region) distributed over its two RNAs. Nucleotide diversity (π) values were relatively low but statistically different over the analyzed genes and subpopulations, indicating their distinct evolutionary history. Values of πp29 and πMP were higher than those of πp15 and πRNA2–IR, whereas πMP was increased due to novel discovered isolates phylogenetically clustered in a divergent clade that we called SJP. Isolate BR_SP_SJP_01 RNA1 and RNA2 sequences, clade SJP, showed an identity of 85.6% and 88.4%, respectively, with those corresponding to CiLV-C, the type member of the genus Cilevirus, and its RNA2 5′-proximal region was revealed as a minor donor in a putative inter-clade recombination event. In addition to citrus, BR_SP_SJP_01 naturally infects the weed Commelina benghalensis and is efficiently transmitted by Brevipalpus yothersi mites. Our data demonstrated that negative selection was the major force operating in the evaluated viral coding regions and defined amino acids putatively relevant for the biological function of cilevirus proteins. This work provides molecular tools and sets up a framework for further epidemiological studies. PMID:27275832

Production of mono- and polyclonal antibodies to Citrus leprosis virus C2 and their application in triple antibody sandwich ELISA and immunocapture RT-PCR diagnostic assays.

PubMed

Choudhary, Nandlal; Roy, Avijit; Leon, M G; Wei, G; Nakhla, M K; Levy, L; Brlansky, R H

2017-05-01

The newly discovered Citrus leprosis virus cytoplasmic type 2 (CiLV-C2) is one of the causal virus of citrus leprosis disease complex; which leads to substantial loss of citrus production in the states of Meta and Casanare of Colombia. Specific and sensitive detection methods are needed to monitor the dissemination of CiLV-C2 in Colombia, and to prevent introduction of CiLV-C2 to other citrus growing countries. Toward this end, putative coat protein gene (CPG) of CiLV-C2 was amplified from CiLV-C2 infected citrus tissues. The CPG was cloned, expressed and purified a recombinant coat protein of ∼31kDa which used to generate monoclonal antibodies and polyclonal antisera. Four monoclonal antibodies and two polyclonal antisera were selected as being specific following Western blotting. The monoclonal antibody MAb E5 and polyclonal antiserum PAb UF715 were selected testing with an extract of CiLV-C2 infected leaves using triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA). In addition, an immunocapture RT-PCR was standardized using MAb E5 for specific and sensitive detection of CiLV-C2. The standardized TAS-ELISA and IC-RT-PCR were able to detect CiLV-C2 in the extracts of symptomatic citrus leprosis tissues up to the dilutions of 1:160 and 1:2580, respectively. Result demonstrated that CiLV-C2 is present in citrus orchards in Meta and Casanare citrus growing areas of Colombia. TAS-ELISA could be used for routine detection of CiLV-C2, epidemiological studies, and for border inspections for quarantine purposes. IC-RT-PCR could be valuable for CiLV-C2 validation and viral genome analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Citrus Functional Genomics and Molecular Modeling in Relation to Citrus sinensis (Sweet Orange) Infection with Xylella fastidiosa (Citrus Variegated Chlorosis).

PubMed

Dwivedi, Upendra N; Tiwari, Sameeksha; Prasanna, Pragya; Awasthi, Manika; Singh, Swati; Pandey, Veda P

2016-08-01

Citrus are among the economically most important fruit tree crops in the world. Citrus variegated chlorosis (CVC), caused by Xylella fastidiosa infection, is a serious disease limiting citrus production at a global scale. With availability of citrus genomic resources, it is now possible to compare citrus expressed sequence tag (EST) data sets and identify single-nucleotide polymorphisms (SNPs) within and among different citrus cultivars that can be exploited for citrus resistance to infections, citrus breeding, among others. We report here, for the first time, SNPs in the EST data sets of X. fastidiosa-infected Citrus sinensis (sweet orange) and their functional annotation that revealed the involvement of eight C. sinensis candidate genes in CVC pathogenesis. Among these genes were xyloglucan endotransglycosylase, myo-inositol-1-phosphate synthase, and peroxidase were found to be involved in plant cell wall metabolism. These have been further investigated by molecular modeling for their role in CVC infection and defense. Molecular docking analyses of the wild and the mutant (SNP containing) types of the selected three enzymes with their respective substrates revealed a significant decrease in the binding affinity of substrates for the mutant enzymes, thus suggesting a decrease in the catalytic efficiency of these enzymes during infection, thereby facilitating a favorable condition for infection by the pathogen. These findings offer novel agrigenomics insights in developing future molecular targets and strategies for citrus fruit cultivation in ways that are resistant to X. fastidiosa infection, and by extension, with greater harvesting efficiency and economic value.

Citrus leprosis research update

USDA-ARS?s Scientific Manuscript database

Citrus leprosis is one of the oldest citrus diseases, but is also one of the most important emerging citrus diseases in South and Central America, and it is apparently spreading northward towards the U.S. Research in our labs and by others has shown that citrus leprosis disease is caused by a compl...

Production of transgenic citrus resistant to citrus canker and Huanglongbing diseases

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the U.S. citrus industry. There are no proven strategies to eliminate HLB disease and no cultivars identified with strong HLB resistance. Citrus canker is also an economically import...

Insect management in deciduous orchard ecosystems: Habitat manipulation

NASA Astrophysics Data System (ADS)

Tedders, W. L.

1983-01-01

Current literature pertaining to habitat manipulation of deciduous fruit and nut orchards for pest control is reviewed. The hypothesis of pesticide-induced pest problems in deciduous orchards as well as the changing pest population dynamics of deciduous orchards is discussed An experimental habitat manipulation program for pecans, utilizing vetch cover crops to enhance lady beetle populations for pecan aphid control is presented

Pollen Competition as a Reproductive Isolation Barrier Represses Transgene Flow between Compatible and Co-Flowering Citrus Genotypes

PubMed Central

Pons, Elsa; Navarro, Antonio; Ollitrault, Patrick; Peña, Leandro

2011-01-01

Background/Objective Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. Methodology/Principal Findings Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17–2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. Conclusions/Significance Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species. PMID:21991359

Pollen competition as a reproductive isolation barrier represses transgene flow between compatible and co-flowering citrus genotypes.

PubMed

Pons, Elsa; Navarro, Antonio; Ollitrault, Patrick; Peña, Leandro

2011-01-01

Despite potential benefits granted by genetically modified (GM) fruit trees, their release and commercialization raises concerns about their potential environmental impact, and the transfer via pollen of transgenes to cross-compatible cultivars is deemed to be the greatest source for environmental exposure. Information compiled from field trials on GM trees is essential to propose measures to minimize the transgene dispersal. We have conducted a field trial of seven consecutive years to investigate the maximum frequency of pollen-mediated crop-to-crop transgene flow in a citrus orchard, and its relation to the genetic, phenological and environmental factors involved. Three different citrus genotypes carrying the uidA (GUS) tracer marker gene (pollen donors) and a non-GM self-incompatible contiguous citrus genotype (recipient) were used in conditions allowing natural entomophilous pollination to occur. The examination of 603 to 2990 seeds per year showed unexpectedly low frequencies (0.17-2.86%) of transgene flow. Paternity analyses of the progeny of subsets of recipient plants using 10 microsatellite (SSR) loci demonstrated a higher mating competence of trees from another non-GM pollen source population that greatly limited the mating chance of the contiguous cross-compatible and flowering-synchronized transgenic pollen source. This mating superiority could be explained by a much higher pollen competition capacity of the non-GM genotypes, as was confirmed through mixed-hand pollinations. Pollen competition strongly contributed to transgene confinement. Based on this finding, suitable isolation measures are proposed for the first time to prevent transgene outflow between contiguous plantings of citrus types that may be extendible to other entomophilous transgenic fruit tree species.

First report of Phyllosticta citricarpa and description of two new species, P. paracapitalensis and P. paracitricarpa, from citrus in Europe.

PubMed

Guarnaccia, V; Groenewald, J Z; Li, H; Glienke, C; Carstens, E; Hattingh, V; Fourie, P H; Crous, P W

2017-06-01

The genus Phyllosticta occurs worldwide, and contains numerous plant pathogenic, endophytic and saprobic species. Phyllosticta citricarpa is the causal agent of Citrus Black Spot disease (CBS), affecting fruits and leaves of several citrus hosts ( Rutaceae ), and can also be isolated from asymptomatic citrus tissues. Citrus Black Spot occurs in citrus-growing regions with warm summer rainfall climates, but is absent in countries of the European Union (EU). Phyllosticta capitalensis is morphologically similar to P. citricarpa , but is a non-pathogenic endophyte, commonly isolated from citrus leaves and fruits and a wide range of other hosts, and is known to occur in Europe. To determine which Phyllosticta spp. occur within citrus growing regions of EU countries, several surveys were conducted (2015-2017) in the major citrus production areas of Greece, Italy, Malta, Portugal and Spain to collect both living plant material and leaf litter in commercial nurseries, orchards, gardens, backyards and plant collections. A total of 64 Phyllosticta isolates were obtained from citrus in Europe, of which 52 were included in a multi-locus (ITS, actA , tef1 , gapdh , LSU and rpb2 genes) DNA dataset. Two isolates from Florida (USA), three isolates from China, and several reference strains from Australia, South Africa and South America were included in the overall 99 isolate dataset. Based on the data obtained, two known species were identified, namely P. capitalensis (from asymptomatic living leaves of Citrus spp.) in Greece, Italy, Malta, Portugal and Spain, and P. citricarpa (from leaf litter of C . sinensis and C . limon ) in Italy, Malta and Portugal. Moreover, two new species were described, namely P. paracapitalensis (from asymptomatic living leaves of Citrus spp.) in Italy and Spain, and P. paracitricarpa (from leaf litter of C . limon ) in Greece. On a genotypic level, isolates of P . citricarpa populations from Italy and Malta (MAT1-2-1) represented a single clone

Microbial inhibitory and radical scavenging activities of cold-pressed terpeneless Valencia orange (Citrus sinensis) oil in different dispersing agents.

PubMed

Chalova, Vesela I; Crandall, Philip G; Ricke, Steven C

2010-04-15

Due to their low solubility in water, oil-based bioactive compounds require dispersion in a surface-active agent or appropriate solvents to ensure maximum contact with microorganisms. These combinations, however, may change their physical and/or chemical characteristics and consequently alter the desired functionality. The objective of this study was to determine the impact of selected dispersing agents, ethanol, dimethyl sulfoxide (DMSO), and Tween-80, on cold-pressed terpeneless (CPT) Valencia orange oil to function as a free radical scavenger and an antimicrobial food additive. When dissolved in ethanol or DMSO, the orange oil fraction had similar minimum inhibitory concentrations (MIC) for Listeria monocytogenes ATCC 19 115 (0.3% and 0.25% v/v respectively), which were significantly lower (P Valencia orange oil should be dispersed in either DMSO or ethanol. (c) 2010 Society of Chemical Industry.

A comparison of groundwater recharge estimation methods in a semi-arid, coastal avocado and citrus orchard (Ventura County, California)

NASA Astrophysics Data System (ADS)

Grismer, Mark E.; Bachman, S.; Powers, T.

2000-10-01

We assess the relative merits of application of the most commonly used field methods (soil-water balance (SWB), chloride mass balance (CMB) and soil moisture monitoring (NP)) to determine recharge rates in micro-irrigated and non-irrigated areas of a semi-arid coastal orchard located in a relatively complex geological environment.Application of the CMB method to estimate recharge rates was difficult owing to the unusually high, variable soil-water chloride concentrations. In addition, contrary to that expected, the chloride concentration distribution at depths below the root zone in the non-irrigated soil profiles was greater than that in the irrigated profiles. The CMB method severely underestimated recharge rates in the non-irrigated areas when compared with the other methods, although the CMB method estimated recharge rates for the irrigated areas, that were similar to those from the other methods, ranging from 42 to 141 mm/year.The SWB method, constructed for a 15-year period, provided insight into the recharge process being driven by winter rains rather than summer irrigation and indicated an average rate of 75 mm/year and 164 mm/year for the 1984 - 98 and 1996 - 98 periods, respectively. Assuming similar soil-water holding capacity, these recharge rates applied to both irrigated and non-irrigated areas. Use of the long period of record was important because it encompassed both drought and heavy rainfall years. Successful application of the SWB method, however, required considerable additional field measurements of orchard ETc, soil-water holding capacity and estimation of rainfall interception - runoff losses.Continuous soil moisture monitoring (NP) was necessary to identify both daily and seasonal seepage processes to corroborate the other recharge estimates. Measured recharge rates during the 1996 - 1998 period in both the orchards and non-irrigated site averaged 180 mm/year. The pattern of soil profile drying during the summer irrigation season, followed

Current seed orchard techniques and innovations

Treesearch

Lawrence K. Miller; Jeffrey DeBell

2013-01-01

As applied forest tree improvement programs in the US Northwest move forward into the third cycle, seed orchards remain as the primary source of genetically improved forest tree seed used for reforestation. The vast majority of seed orchards in this region are coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), consistent with the high economic importance of...

Student Health Services at Orchard Ridge.

ERIC Educational Resources Information Center

Nichols, Don D.

This paper provides a synoptic review of student health services at the community college level while giving a more detailed description of the nature of health services at Orchard Ridge, a campus of Oakland Community College. The present College Health Service program provides for a part-time (24 hrs./wk.) nurse at Orchard Ridge. A variety of…

33 CFR 334.1230 - Port Orchard; naval restricted area.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Port Orchard; naval restricted... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.1230 Port Orchard; naval restricted area. (a) Port Orchard; naval restricted area—(1) The area. Shoreward of a line beginning at a...

33 CFR 334.1230 - Port Orchard; naval restricted area.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Port Orchard; naval restricted... ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.1230 Port Orchard; naval restricted area. (a) Port Orchard; naval restricted area—(1) The area. Shoreward of a line beginning at a...

Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

PubMed

Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

2010-03-24

To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

Field ID guide to citrus relative hosts of Asian citrus psyllid & Huanglongbing

USDA-ARS?s Scientific Manuscript database

The Rutaceae family of plants includes not only species within the genus Citrus, but also several other genera and species that may not be easily recognized as having any relationship to citrus at all. However, many of these citrus relatives are used for ornamental, culinary, or religious purposes. ...

Late Quaternary environmental history of Lake Valencia, Venezuela

USGS Publications Warehouse

Bradbury, J. Platt; Leyden, B.; Baker, M.R.; Lewis, W.M.; Schubert, C.; Binford, M.W.; Whitehead, D.R.; Weibezahn, F.H.

1981-01-01

Chemical, paleontological, and mineralogical analyses of a 7.5-meter core from the middle of Lake Valencia, Venezuela, have provided information on the paleoclimatic history of this low-elevation, low-latitude site for the last 13,000 years. The data show that dry climates existed in this region from 13,000 years before present (B.P.) until about 10,000 years B.P. The Lake Valencia Basin was occupied by intermittent saline marshes at that time. About 10,000 years B.P., a permanent lake of fluctuating salinity formed and arboreal plant communities replaced the earlier dominant xeric herbaceous vegetation and marsh plants. By 8500 years B.P., Lake Valencia reached moderate to low salinities and discharged water; the modern vegetation became established at that time. After 8500 years B.P., the lake twice ceased discharging as a result of reduced watershed moisture. The second of these drying episodes is still in progress and has been aggravated by human activities in the watershed.

Late quaternary environmental history of Lake Valencia, Venezuela

USGS Publications Warehouse

Platt, Bradbury J.; Leyden, B.; Salgado-Labouriau, M.; Lewis, W.M.; Schubert, C.; Binford, M.W.; Frey, D.G.; Whitehead, D.R.; Weibezahn, F.H.

1981-01-01

Chemical, paleontological, and mineralogical analyses of a 7.5-meter core from the middle of Lake Valencia, Venezuela, have provided information on the paleoclimatic history of this low-elevation, low-latitude site for the last 13,000 years. The data show that dry climates existed in this region from 13,000 years before present (B.P.) until about 10,000 years B.P. The Lake Valencia Basin was occupied by intermittent saline marshes at that time. About 10,000 years B.P., a permanent lake of fluctuating salinity formed and arboreal plant communities replaced the earlier dominant xeric herbaceous vegetation and marsh plants. By 8500 years B.P., Lake Valencia reached moderate to low salinities and discharged water; the modern vegetation became established at that time. After 8500 years B.P., the lake twice ceased discharging as a result of reduced watershed moisture. The second of these drying episodes is still in progress and has been aggravated by human activities in the watershed. Copyright ?? 1981 AAAS.

Antioxidant activity of oils extracted from orange (Citrus sinensis) seeds.

PubMed

Jorge, Neuza; Silva, Ana Carolina da; Aranha, Caroline P M

2016-05-31

Due to the increasing production of food in the world with consequent increase of the production of waste, the importance of developing researches for its use is noticed. Thus, the interest in vegetable oils with bioactive compounds, such as the ones extracted from fruit seeds, is growing. Therefore, the present study aims to characterize the oils extracted from seeds of Hamlin, Natal, Pera-rio and Valencia orange varieties (Citrus sinensis), as to the levels of total carotenoids, total phenolic compounds, tocopherols and phytosterols, as well as to determine their antioxidant activity. The orange seed oils presented important content of total carotenoids (19.01 mg/kg), total phenolic compounds (4.43 g/kg), α-tocopherol (135.65 mg/kg) and phytosterols (1304.2 mg/kg). The antioxidant activity ranged from 56.0% (Natal) to 70.2% (Pera-rio). According to the results it is possible to conclude that the orange seed oils can be used as specialty oils in diet, since they contain considerable amounts of bioactive compounds and antioxidants.

Highly erodible terrain in agriculture land against chipped pruned branches. Or how to stop the soil erosion with low investment

NASA Astrophysics Data System (ADS)

Cerdà, A.

2009-04-01

The session on "Soil erosion and sediment control with vegetation and bioengineering on severely eroded terrain" pays special attention to the severe soil erosion suffered on steep slopes and erodible parent materials and soils. Within the last 20 years, in the Mediterranean lands, the citrus orchards were reallocated on steep slopes due to the urban development and better climatic and management conditions of the new plantations. The lack of vegetation cover on the new slope plantations of citrus resulted in high erosion rates. Those non-sustainable soil losses were measured by means of rainfall simulation experiments, Gerlach collectors, geomorphological transect and topographical measurements. The October 2007 and October 2008 rainy periods resulted in sheet, rill and gully erosion. Some recently planted orchards (2005) had the first pruning season in 2008. The pruned chipped branches reduced the soil losses to 50 % of the expected, although the litter (pruned branches) covered 4.67 % of the soil. This is why a research was developed by means of simulated rainfall experiments to determine the vegetation cover (litter, mainly leaves) to protect the soil to reach a sustainable erosion rate. Rainfall simulation experiments at 43 mm h-1 where performed on 1 m2 plots covered with 0, 3, 7, 15, 30, 45, 60, 80 and 100 % litter cover (pruned chipped branches) to determine the sustainable litter cover to avoid the soil losses. The results show that more that 45 % litter cover almost reduces the soil losses to negligible rates. The results confirm that 4 % of vegetation cover reduces the soil losses to 50 %. Key words: Agriculture land, erodible terrain, land management, citrus, erosion, Spain, Valencia, herbicides. Acknowledgements, We thanks the financial support of the Ministerio de Ciencia e Innovación by means of the project CGL2008-02879/BTE, "PERDIDA DE SUELO EN NUEVAS EXPLOTACIONES CITRICOLAS EN PENDIENTE. ESTRATEGIAS PARA EL CONTROL DE LA EROSION HIDRICA"

The WRKY Transcription Factor Family in Citrus: Valuable and Useful Candidate Genes for Citrus Breeding.

PubMed

Ayadi, M; Hanana, M; Kharrat, N; Merchaoui, H; Marzoug, R Ben; Lauvergeat, V; Rebaï, A; Mzid, R

2016-10-01

WRKY transcription factors belong to a large family of plant transcriptional regulators whose members have been reported to be involved in a wide range of biological roles including plant development, adaptation to environmental constraints and response to several diseases. However, little or poor information is available about WRKY's in Citrus. The recent release of completely assembled genomes sequences of Citrus sinensis and Citrus clementina and the availability of ESTs sequences from other citrus species allowed us to perform a genome survey for Citrus WRKY proteins. In the present study, we identified 100 WRKY members from C. sinensis (51), C. clementina (48) and Citrus unshiu (1), and analyzed their chromosomal distribution, gene structure, gene duplication, syntenic relation and phylogenetic analysis. A phylogenetic tree of 100 Citrus WRKY sequences with their orthologs from Arabidopsis has distinguished seven groups. The CsWRKY genes were distributed across all ten sweet orange chromosomes. A comprehensive approach and an integrative analysis of Citrus WRKY gene expression revealed variable profiles of expression within tissues and stress conditions indicating functional diversification. Thus, candidate Citrus WRKY genes have been proposed as potentially involved in fruit acidification, essential oil biosynthesis and abiotic/biotic stress tolerance. Our results provided essential prerequisites for further WRKY genes cloning and functional analysis with an aim of citrus crop improvement.

Does citrus leaf miner impair hydraulics and fitness of citrus host plants?

PubMed

Raimondo, Fabio; Trifilò, Patrizia; Gullo, Maria A Lo

2013-12-01

Gas exchange and hydraulic features were measured in leaves of three different Citrus species (Citrus aurantium L., Citrus limon L., Citrus  ×  paradisii Macfad) infested by Phyllocnistis citrella Staiton, with the aim to quantify the impact of this pest on leaf hydraulics and, ultimately, on plant fitness. Infested leaves were characterized by the presence on the leaf blade of typical snake-shaped mines and, in some cases, of a crumpled leaf blade. Light microscopy showed that leaf crumpling was induced by damage to the cuticular layer. In all three Citrus species examined: (a) the degree of infestation did not exceed 10% of the total surface area of infested plants; (b) control and infested leaves showed similar values of minimum diurnal leaf water potential, leaf hydraulic conductance and functional vein density; and (c) maximum diurnal values of stomatal conductance to water vapour, transpiration rate and photosynthetic rate (An) were similar in both control leaves and the green areas of infested leaves. A strong reduction of An was recorded only in mined leaf areas. Our data suggest that infestation with P. citrella does not cause conspicuous plant productivity reductions in young Citrus plants, at least not in the three Citrus species studied here.

Herpetofaunal assemblages of a lowland broadleaf forest, an overgrown orchard forest and a lime orchard in Stann Creek, Belize

PubMed Central

Gray, Russell; Strine, Colin T.

2017-01-01

Abstract Understanding and monitoring ecological impacts of the expanding agricultural industry in Belize is an important step in conservation action. To compare possible alterations in herpetofaunal communities due to these anthropogenic changes, trapping arrays were set in a manicured orchard, a reclaimed orchard and a lowland broadleaf forest in Stann Creek district at Toucan Ridge Ecology and Education Society (TREES). Trapping efforts were carried out during the rainy season, from June to September, 2016, during which time the study site was hit by a category one hurricane between sampling sessions. Trapping yielded 197 individual herpetofauna and 40 different species overall; 108 reptile captures (30 species) and 88 amphibian captures (ten species). Reptiles and amphibians were more abundant in the lowland broadleaf forest and the manicured orchard area. Amphibian species diversity was relatively similar in each habitat type. Reptile captures were most diverse in the Overgrown Orchard Forest (OGF) and Overgrown Orchard Riparian Forest (OGR) and least diverse in the Lowland Broadleaf Forest (LBF). The findings of this study suggest that reptile and amphibian sensitivity to anthropogenically altered areas is minimal when enveloped by natural habitat buffers, and additionally, that extreme weather events have little impact on herpetofauna communities in the area. PMID:29118630

Avian nesting success and diversity in conventionally and organically managed apple orchards

USGS Publications Warehouse

Fluetsch, K.M.; Sparling, D.W.

1994-01-01

This study examines the effects of operational use of pesticides on avian species inhabiting apple orchards in Pennsylvania. Mourning dove (Zenaida rnacroura) and American robin (Turdus migratorius) nests were monitored in three organic and three conventional apple orchards during 1990 and 1991. In 1991 we surveyed the avian communities of these orchards by using line transects. Organophosphorus (OP) (e.g., azinphos-methyl, phosphamidon, parathion, dimethoate), carbamate (CA) (e.g., methomyl, formetanate, oxamyl), and organochlorine (endosulfan) pesticides, known to be highly toxic to birds, were sprayed individually or in mixtures as part of routine pest management as many as 19 times during peaks in breeding activity. Spray card tests revealed that OP pesticides were deposited on 86% of the nests in conventional orchards. Daily survival rates (DSRs) for nests of both species were higher in the organic orchards than in the conventional orchards for 1991 and for years combined (p < 0.05). Species diversity was greater in the organic orchards (H= 2.43) than in the conventional orchards (H=1.79). Repeated applications of pesticides within the conventional orchards reduced the reproductive success of doves and robins and may have lowered avian species diversity compared with organic orchards.

Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata

PubMed Central

Beloti, Vitor Hugo; Alves, Gustavo Rodrigues; Araújo, Diogo Feliciano Dias; Picoli, Mateus Manara; Moral, Rafael de Andrade; Demétrio, Clarice Garcia Borges; Yamamoto, Pedro Takao

2015-01-01

Huanglongbing (HLB) is a disease associated with the bacteria “Candidatus Liberibacter spp.” and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston), the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1), 12% as slightly harmful (Class 2), 12% as moderately harmful (Class 3) and 56% as harmful (Class 4), according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful) were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless) were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases. PMID:26132327

Citrus Research Board-sponsored review of the University of California Riverside citrus breeding

USDA-ARS?s Scientific Manuscript database

In October 2015 the Citrus Research Board (CRB) assembled a panel of experts to review the Citrus Research Board-sponsored Citrus Research and Genetics Programs at University of California Riverside (UCR). The panel consisted of: Gennaro Fazio, USDA/ARS, Geneva, NY; Maria Angeles Forner-Giner, Insti...

Nematode Community Composition under Various Irrigation Schemes in a Citrus Soil Ecosystem.

PubMed

Porazinska, D L; McSorley, R; Duncan, L W; Graham, J H; Wheaton, T A; Parsons, L R

1998-06-01

Interest in the sustainability of farming practices has increased in response to environmental problems associated with conventional agricultural management often adopted for the production of herbaceous crops, ornamentals, and fruit crops. Availability of measures of the status of the soil ecosystem is of immediate importance, particularly for environmental assessment and monitoring programs. This study investigated the effects of various irrigation regimes (an example of an agricultural management practice) on the structure of the nematode fauna in a citrus orchard in the sandy ridge area of Central Florida. Ecological measures such as community structure indices, diversity indices, and maturity indices were assessed and related to irrigation intensity. Maturity index was an effective measure in distinguishing differences between irrigation regimes, whereas other indices of community structure were not. Of various nematode genera and trophic groups, only omnivores and the omnivore genera. Aporcelaimellus and Eudorylaimus responded to irrigation treatments.

Seasonal population dynamics of Homalodisca vitripennis (Hemiptera: Cicadellidae) in sweet orange trees maintained under continuous deficit irrigation.

PubMed

Krugner, Rodrigo; Groves, Russell L; Johnson, Marshall W; Flores, Arnel P; Hagler, James R; Morse, Joseph G

2009-06-01

A 2-yr study was conducted in a citrus orchard (Citrus sinensis L. Osbeck cultivar Valencia) to determine the influence of plant water stress on the population dynamics of glassy-winged sharpshooter, Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop evapotranspiration rate (ET(c)) and continuous deficit-irrigation regimens at 80 and 60% ET(c). Microclimate and plant conditions monitored included temperature and humidity in the tree canopy, leaf surface temperature, water potential, and fruit quality and yield. Glassy-winged sharpshooter population densities and activity were monitored weekly by a combination of visual inspections, beat net sampling, and trapping. Glassy-winged sharpshooter populations were negatively affected by severe plant water stress; however, population densities were not linearly related to decreasing water availability in plants. Citrus trees irrigated at 60% ET(c) had significantly warmer leaves, lower xylem water potential, and consequently hosted fewer glassy-winged sharpshooter eggs, nymphs, and adults than trees irrigated at 80% ET(c). Citrus trees irrigated at 100% ET(c) hosted similar numbers of glassy-winged sharpshooter stages as trees irrigated at 60% ET(c) and a lower number of glassy-winged sharpshooter nymphs than the 80% ET(c) treatment, specifically during the nymphal density peak in mid-April to early July. Irrigation treatments did not affect populations of monitored natural enemies. Although the adult glassy-winged sharpshooter population was reduced, on average, by 50% in trees under severe water stress, the total number of fruit and number of fruit across several fruit grade categories were significantly lower in the 60% ET(c) than in the 80 and 100% ET(c) irrigation treatments.

Weedy hosts and prevalence of potential leafhopper vectors (Hemiptera: Cicadellidae) of a phytoplasma (16SrIX group) associated with Huanglongbing symptoms in citrus groves.

PubMed

Marques, R N; Teixeira, D C; Yamamoto, P T; Lopes, J R S

2012-04-01

Huanglongbing (HLB) is a severe citrus (Citrus spp.) disease associated with the bacteria genus Candidatus Liberibacter, detected in Brazil in 2004. Another bacterium was found in association with HLB symptoms and characterized as a phytoplasma belonging to the 16SrIX group. The objectives of this study were to identify potential leafhopper vectors of the HLB-associated phytoplasma and their host plants. Leafhoppers were sampled every other week for 12 mo with sticky yellow cards placed at two heights (0.3 and 1.5 m) in the citrus tree canopy and by using a sweep net in the ground vegetation of two sweet orange, Citrus sinensis (L.) Osbeck, groves infected by the HLB-phytoplasma in São Paulo state. Faunistic analyses indicated one Agalliinae (Agallia albidula Uhler) and three Deltocephalinae [Balclutha hebe (Kirkaldy), Planicephalus flavicosta (Stål), and Scaphytopius (Convelinus) marginelineatus (Stål)] species, as the most abundant and frequent leafhoppers (Hemiptera: Cicadellidae). Visual observations indicated an association of leafhopper species with some weeds and the influence of weed species composition on leafhopper abundance in low-lying vegetation. S. marginelineatus and P. flavicosta were more frequent on Sida rhombifolia L. and Althernantera tenella Colla, respectively, whereas A. albidula was observed more often on Conyza bonariensis (L.) Cronq. and B. hebe only occurred on grasses. DNA samples of field-collected S. marginelineatus were positive by polymerase chain reaction and sequencing tests for the presence of the HLB-phytoplasma group, indicating it as a potential vector. The association of leafhoppers with their hosts may be used in deciding which management strategies to adopt against weeds and diseases in citrus orchards.

An investigation of boron-toxicity in leaves of two citrus species differing in boron-tolerance using comparative proteomics.

PubMed

Sang, Wen; Huang, Zeng-Rong; Qi, Yi-Ping; Yang, Lin-Tong; Guo, Peng; Chen, Li-Song

2015-06-18

Limited data are available on boron (B)-toxicity-responsive proteins in plants. We first applied 2-dimensional electrophoresis (2-DE) to compare the effects of B-toxicity on leaf protein profiles in B-tolerant Citrus sinensis and B-intolerant Citrus grandis seedlings, and identified 27 (20) protein species with increased abundances and 23 (25) protein species with decreased abundances from the former (latter). Generally speaking, B-toxicity increased the abundances of protein species involved in antioxidation and detoxification, proteolysis, cell transport, and decreased the abundances of protein species involved in protein biosynthesis in the two citrus species. The higher B-tolerance of C. sinensis might include following several aspects: (a) protein species related to photosynthesis and energy metabolism in C. sinensis leaves were more adaptive to B-toxicity than in C. grandis ones, which was responsible for the higher photosynthesis and for the better maintenance of energy homeostasis in the former; and (b) the increased requirement for detoxification of reactive oxygen species and cytotoxic compounds due to decreased photosynthesis was less in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. B-toxicity-responsive protein species involved in coenzyme biosynthesis differed between the two species, which might also contribute to the higher B-tolerance of C. sinensis. B-toxicity occurs in many regions all over the world, especially in arid and semiarid regions due to the raising of B-rich water tables with high B accumulated in topsoil. In China, B-toxicity often occurs in some citrus orchards. However, the mechanisms of citrus B-tolerance are still not fully understood. Here, we first used 2-DE to identify some new B-toxicity-responsive-proteins involved in carbohydrate and energy metabolism, antioxidation and detoxification, signal transduction and nucleotide metabolism. Our results showed that proteins involved in photosynthesis and energy metabolism

Apple orchard pest control strategies affect bird communities in southeastern France.

PubMed

Bouvier, Jean-Charles; Ricci, Benoît; Agerberg, Julia; Lavigne, Claire

2011-01-01

Birds are regarded as appropriate biological indicators of how changes in agricultural practices affect the environment. They are also involved in the biocontrol of pests. In the present study, we provide an assessment of the impact of pest control strategies on bird communities in apple orchards in southeastern France. We compared the structure (abundance, species richness, and diversity) of breeding bird communities in 15 orchards under conventional or organic pest control over a three-year period (2003-2005). Pest control strategies and their evolution over time were characterized by analyzing farmers' treatment schedules. The landscape surrounding the orchards was characterized using a Geographic Information System. We observed 30 bird species overall. Bird abundance, species richness, and diversity were all affected by pest control strategies, and were highest in organic orchards and lowest in conventional orchards during the three study years. The pest control strategy affected insectivores more than granivores. We further observed a tendency for bird communities in integrated pest management orchards to change over time and become increasingly different from communities in organic orchards, which also corresponded to changes in treatment schedules. These findings indicate that within-orchard bird communities may respond quickly to changes in pesticide use and may, in turn, influence biocontrol of pests by birds. © 2010 SETAC.

Phosmet residues in an orchard and adjacent recreational area.

PubMed

MacNeil, J D; Hikichi, M

1986-10-01

Two cover sprays of phosmet were applied to an orchard adjoining a camping area and a bird sanctuary with a resident goose population. Insecticide residues were monitored on orchard leaves, orchard ground cover, ground cover in the camp-site and along the adjacent lakeshore. Despite attempts to minimize drift, significant spray residues were found outside the target area. Residues on ground cover and leaves were reduced by sprinkler irrigation subsequent to spray application.

Expressed Genes in Asian Citrus Psyllid adults feeding on citrus

USDA-ARS?s Scientific Manuscript database

We created and described the first genetic data set from the Asian citrus psyllid, AsCP, Diaphorina citri, Kuwayama (Hemiptera: Psyllidae). The AsCP spread the plant-infecting bacterium, Candidatus Liberibacter asiaticus, which is associated with the citrus disease Huanglongbing, HLB, known as Citru...

Within-orchard edge effects of the azimuth of the sun on Diaphorina citri adults in mature orchards

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB) has been considered the most devastating disease of citrus. The bacterium and vector associated with HLB in Florida are ‘Candidatus Liberibacter asiaticus’ and Diaphorina citri (Asian citrus psyllid), respectively. D. citri is positively phototropic, and higher populations have b...

PESTICIDE ORCHARD ECOSYSTEM MODEL (POEM): A USER'S GUIDE

EPA Science Inventory

A mathematical model was developed to predict the transport and effects of a pesticide in an orchard ecosystem. The environmental behavior of azinphosmethyl was studied over a two-year period in a Michigan apple orchard. Data were gathered for the model on initial distribution wi...

Orchard nitrogen management: Which nitrogen source is best?

USDA-ARS?s Scientific Manuscript database

Suboptimal management of nitrogen fertility in pecan orchards leads to a loss of nutmeat yield and quality, but also a waste of natural resources and money. This article reviews several basic guiding principles useful to orchard managers when developing nitrogen management strategies, and determini...

Citrus Huanglongbing tolerance in Australian Citrus Relatives, Microcitrus and Eremocirus

USDA-ARS?s Scientific Manuscript database

Tolerance, or resistance to citrus huanglongbing will be important as a long term solution for this disease. In a field trial conducted with over 1000 plants belonging to different genera in the sub-family Aurantioideae, we observed field tolerance in many Australian citrus relatives. To confirm the...

Dualities in Architectural Training: The Architecture School of Valencia (1968-1975)

ERIC Educational Resources Information Center

Domingo-Calabuig, Débora

2018-01-01

The school of Valencia was a singular case study in the architectural training in Spain towards the end of the 60s. Like in Madrid, Barcelona, and Seville, the school also participated in the bustling political and social context, but while in these schools the curriculum of 1964 was extended until 1975, in Valencia the creation of the Instituto…

Effects of open-top chambers on 'Valencia' orange trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olszyk, D.M.; Takemoto, B.K.; Kats, G.

1992-01-01

Young 'Valencia' orange trees (Citrus sinensis(L) Osbeck) were grown for four years in large open-top chambers with ambient (nonfiltered) air or in outside air to determine any effects of the chambers on the air pollutant susceptibility of the trees. Long-term ozone average concentrations (12 hours, growing season) were 8% lower, and cumulative ozone dose (hourly values >0.1 microL/L) was 29% lower in ambient chambers compared to outside air. Fruit yields were much higher (>39%) for ambient chamber trees than for outside trees over three harvests, due at least partly to less fruit drop during the growing season for ambient chambermore » trees. Ambient chamber trees were much larger than outside trees and produced over twice as much leaf material over four years of study. Leaves on ambient chamber trees were larger and less dense than on outside trees. Leaves on ambient chamber trees were under more stress than leaves on outside trees during summer months; with lower stomatal conductances (14% average) and transpiration rates (12%), and more negative leaf water pressure potentials (28%). In contrast, leaves on ambient chamber trees had higher net photosynthetic rates (13%) and higher leaf starch concentrations prior to tree flowering (31%), than leaves on outside trees. While these results indicated large long-term impacts on tree growth which must be considered when using open-top chambers, they did not indicate any net effect of chambers on the air pollutant susceptibility of trees which would limit the usefulness of chamber tree data for air quality impact assessment purposes.« less

Molecular characterization and phylogenetic analysis of Citrus viroid VI variants from citrus in China

USDA-ARS?s Scientific Manuscript database

Citrus viroid VI (CVd-VI) was originally found from citrus and persimmon in Japan. We report here the identification and molecular characterization of CVd-VI from four production regions of China. A total of 90 cDNA clones from nine infected citrus cultivars were sequenced. The sequence homologies o...

The effects of orchard pesticide applications on breeding robins

USGS Publications Warehouse

Johnson, E.V.; Mack, G.L.; Thompson, D.Q.

1976-01-01

From 1966 through 1968, robins reproduced successfully in commercial apple orchards which were periodically sprayed with DDT, dieldrin, and other pesticides. Observations by a Z-man team using walkie-talkies revealed that breeding robins obtained essentially all food for themselves and nestlings from unsprayed areas adjacent to the orchards. Invertebrate trapping in sprayed and unsprayed areas showed that these food items were 5 or 6 times more abundant in unsprayed habitat. Worms forced to live in sprayed orchard soil displayed significantly greater mortality than controls. Mean robin clutch sizes in the study orchards were lower than those reported for robins in other studies, perhaps because of food shortage and/or increased foraging distances. Levels of DDT and its analogs in food items from robin foraging areas did not exceed 8 ppm wet weight basis. From late April to July, adult robins showed small but significant increases in DDE levels in all tissues examined, as well as an increase in dieldrin in brains. Pesticides sprayed on the farm had no direct demonstrable adverse effects on the robins; productivity was high and adult mortality low. The situation was in large measure fortuitous, since any changes in orchard management practices which resulted in the presence or availability of invertebrates under orchard trees would be expected to result in robin mortality and/or reduced breeding success.

Antioxidant Capacity, Anticancer Ability and Flavonoids Composition of 35 Citrus (Citrus reticulata Blanco) Varieties.

PubMed

Wang, Yue; Qian, Jing; Cao, Jinping; Wang, Dengliang; Liu, Chunrong; Yang, Rongxi; Li, Xian; Sun, Chongde

2017-07-05

Citrus ( Citrus reticulate Blanco) is one of the most commonly consumed and widely distributed fruit in the world, which is possessing extensive bioactivities. Present study aimed to fully understand the flavonoids compositions, antioxidant capacities and in vitro anticancer abilities of different citrus resources. Citrus fruits of 35 varieties belonging to 5 types (pummelos, oranges, tangerines, mandarins and hybrids) were collected. Combining li quid chromatography combined with electrospray ionization mass spectrometry (LC-ESI-MS/MS) and ultra-performance liquid chromatography combined with diode array detector (UPLC-DAD), a total of 39 flavonoid compounds were identified, including 4 flavones, 9 flavanones and 26 polymethoxylated flavonoids (PMFs). Each citrus fruit was examined and compared by 4 parts, flavedo, albedo, segment membrane and juice sacs. The juice sacs had the lowest total phenolics, following by the segment membrane. Four antioxidant traits including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) and cupric reducing antioxidant capacity (CUPRAC) were applied for the antioxidant capacities evaluation. Three gastric cancer cell lines, SGC-7901, BGC-823 and AGS were applied for the cytotoxicity evaluation. According to the results of correlation analysis, phenolics compounds might be the main contributor to the antioxidant activity of citrus extracts, while PMFs existing only in the flavedo might be closely related to the gastric cancer cell line cytotoxicity of citrus extracts. The results of present study might provide a theoretical guidance for the utilization of citrus resources.

Great tits (Parus major) reduce caterpillar damage in commercial apple orchards.

PubMed

Mols, Christel M M; Visser, Marcel E

2007-02-07

Alternative ways to control caterpillar pests and reduce the use of pesticides in apple orchards are in the interest of the environment, farmers and the public. Great tits have already been shown to reduce damage under high caterpillar density when breeding in nest boxes in an experimental apple orchard. We tested whether this reduction also occurs under practical conditions of Integrated Pest Management (IPM), as well as Organic Farming (OF), by setting up an area with nest boxes while leaving a comparable area as a control within 12 commercial orchards. We showed that in IPM orchards, but not in OF orchards, in the areas with breeding great tits, apples had 50% of the caterpillar damage of the control areas. Offering nest boxes to attract insectivorous passerines in orchards can thus lead to more limited pesticide use, thereby adding to the natural biological diversity in an agricultural landscape, while also being economically profitable to the fruit growers.

Cultivar evaluation and development for black walnut orchards

Treesearch

William Reid; Mark V. Coggeshall; Kenneth L. Hunt

2004-01-01

Black walnut is an underdeveloped orchard crop. Hundreds of cultivars have been named but a commercial orchard industry has not developed. The horticultural characteristics of currently available black walnut cultivars are reviewed. Important cultivar traits include: leaving date, flowering date, growth habit, disease susceptibility, yield, and nut quality. Breeding...

Science support for evaluating natural recovery of polychlorinated biphenyl concentrations in fish from Crab Orchard Lake, Crab Orchard National Wildlife Refuge, Illinois

USGS Publications Warehouse

Kunz, Bethany K.; Hinck, Jo E.; Calfee, Robin D.; Linder, Greg L.; Little, Edward E.

2018-05-11

IntroductionCrab Orchard Lake in southern Illinois is one of the largest and most popular recreational lakes in the state. Construction of the nearly 7,000-acre reservoir in the late 1930s created employment opportunities through the Works Progress Administration, and the lake itself was intended to supply water, control flooding, and provide recreational opportunities for local communities (Stall, 1954). In 1942, the Department of War appropriated or purchased more than 20,000 acres of land around Crab Orchard Lake and constructed the Illinois Ordnance Plant, which manufactured bombs and anti-tank mines during World War II. After the war, an Act of Congress transferred the property to the U.S. Department of the Interior. Crab Orchard National Wildlife Refuge was established on August 5, 1947, for the joint purposes of wildlife conservation, agriculture, recreation, and industry. Production of explosives continued, but new industries also moved onsite. More than 200 tenants have held leases with Crab Orchard National Wildlife Refuge and have operated a variety of manufacturing plants (electrical components, plated metal parts, ink, machined parts, painted products, and boats) on-site. Soils, water, and sediments in several areas of the refuge were contaminated with hazardous substances from handling and disposal methods that are no longer acceptable environmental practice (for example, direct discharge to surface water, use of unlined landfills).Polychlorinated biphenyl (PCB) contamination at the refuge was identified in the 1970s, and a PCB-based fish-consumption advisory has been in effect since 1988 for Crab Orchard Lake. The present advisory covers common carp (Cyprinus carpio) and channel catfish (Ictalurus punctatus); see Illinois Department of Public Health (2017). Some of the most contaminated areas of the refuge were actively remediated, and natural ecosystem recovery processes are expected to further reduce residual PCB concentrations in the lake. The U

Slight Fermentation with Lactobacillus fermentium Improves the Taste (Sugar:Acid Ratio) of Citrus (Citrus reticulata cv. chachiensis) Juice.

PubMed

Yu, Yuanshan; Xiao, Gengsheng; Xu, Yujuan; Wu, Jijun; Fu, Manqin; Wen, Jing

2015-11-01

The aim of this study was to evaluate the hypothesis that fermentation with Lactobacillus fermentium, which can metabolize citric acid, could be applied in improving the taste (sugar:acid ratio) of citrus juice. During fermentation, the strain of L. fermentium can preferentially utilize citric acid of citrus (Citrus reticulata cv. Chachiensis) juice to support the growth without the consumption of sugar. After 6 h of fermentation with L. fermentium at 30 °C, the sugar:acid ratio of citrus juice increased to 22:1 from 12:1, which resulted in that the hedonic scores of sweetness, acidity and overall acceptability of fermented-pasteurized citrus juice were higher than the unfermented-pasteurized citrus juice. Compared with unfermented-pasteurized citrus juice, the ORAC value and total amino acid showed a reduction, and no significant change (P > 0.05) in the L*, a*, b*, total soluble phenolics and ascorbic acid (Vc) content in the fermented-pasteurized citrus juice was observed as compared with unfermented-pasteurized citrus juice. Hence, slight fermentation with L. fermentium can be used for improving the taste (sugar:acid ratio) of citrus juice with the well retaining of quality. © 2015 Institute of Food Technologists®

The importance of traditional orchards for breeding birds: The preliminary study on Central European example

NASA Astrophysics Data System (ADS)

Kajtoch, Łukasz

2017-01-01

Orchards are parts of agriculture and apart from their economic role they may preserve biodiversity in highly transformed farmlands. An increasing intensity of orchards management is known to be threat for some species, especially pollinators and birds. On the other hand, the biodiversity of abandoned orchards was hardly investigated. Here, I present a survey of orchards in Poland to estimate how bird's diversities differ in response to the intensity of orchards management. In 2014, 66 orchards of three types - abandoned, extensively and intensively managed - were investigated. Bird species' richness and abundance were found to be highest in abandoned orchards but overall bird diversity and species composition in abandoned did not differ from these found in extensively managed orchards. In abandoned and extensively managed orchards, hollow-dwellers and insectivores (with some rare old-forest associated species) dominated, whereas in intensively managed orchards the most diverse were ground-dwellers. Among the several selected environmental features, the highest impact on bird diversity was related to the tree diversity, abundance of older trees, presence of multilayer understory and heterogeneous surrounding. The preliminary study point that traditional orchards could play a important role for wood-dwelling species in agriculture and because of that the removal or replacement of all traditional orchards by intensively managed orchards should be avoided and needs of orchard protection should be implemented into Agri-Environmental Schemes/High Nature Value farming systems and possibly also into habitat directive of EU. Unfortunately, the number of abandoned and extensively managed orchards is declining from agricultural landscapes, and traditional orchards are replaced by conventional fruit plantations.

school in Valencia before the Civil War.

PubMed

Ferrandis, Xavier García; Vidal, Àlvar Martínez

During the first third of the 20th century, the dental profession in Spain was disputed by several groups of healthcare professionals, including surgery practitioners and dental technicians. The most intense conflict was between dentists and stomatologists. In the case of Valencia, this struggle became apparent in the attempt to create a dental school during the first Spanish Republican period. This project was supported by the Faculty of Medicine and by the local authorities but was not implemented due to the special interests of practicing dentists and the School of Dentistry in the Central University of Madrid. The institutionalization of dentistry in Valencia was limited to the teaching of an isolated subject in the Faculty of Medicine, preventing the adoption of a university model that would have encouraged the consolidation of the dental profession in all its aspects, not solely in terms of improvements in dental care. Opposition to the project was largely based on a campaign to discredit its main promoter, Rafael Fiol Vilar (1885-1971). This Valencian doctor and dentist is virtually unknown by historians, but he had an excellent academic background and an extraordinary international projection for that time. He may have been ignored because of his exile after the Spanish Civil War and the failure of his project for the University of Valencia.

An Ecoinformatics Approach to Field-Scale Evaluation of Insecticide Effects in California Citrus: Are Citrus Thrips and Citrus Red Mite Induced Pests?

PubMed

Livingston, George; Hack, Lindsey; Steinmann, Kimberly P; Grafton-Cardwell, Elizabeth E; Rosenheim, Jay A

2018-05-28

Experimental approaches to studying the consequences of pesticide use, including impacts on beneficial insects, are vital; however, they can be limited in scale and realism. We show that an ecoinformatics approach that leverages existing data on pesticides, pests, and beneficials across multiple fields can provide complementary insights. We do this using a multi-year dataset (2002-2013) on pesticide applications and density estimates of two pests, citrus thrips (Scirtothrips citri (Moulton [Thysanoptera: Thripidae])) and citrus red mites (Panonychus citri McGregor [Acari: Tetranychidae]), and a natural enemy (Euseius spp. predatory mites) collected from citrus groves in the San Joaquin Valley of California. Using correlative analyses, we investigated the long-term consequences of pesticide use on S. citri and P. citri population densities to evaluate the hypothesis that the pest status of these species is largely due to the disruption of natural biological control-i.e., these are induced pests. We also evaluated short-term pesticide efficacy (suppression of citrus thrips and citrus red mite populations immediately post-application) and asked if it was correlated with the suppression of Euseius predator populations. Although the short-term efficacy of different pesticides varied significantly, our dataset does not suggest that the use of citrus pesticides suppressed Euseius densities or worsened pest problems. We also find that there is no general trade-off between pesticide efficacy and pesticide risk to Eusieus, such that highly effective and minimally disruptive compounds were available to citrus growers during the studied time period.

Evaluation of resistance to asiatic citrus canker among selections of pera sweet orange (Citrus sinensis)

USDA-ARS?s Scientific Manuscript database

Asiatic citrus canker (ACC, caused by the bacterium Xanthomonas citri subsp. citri) is a destructive disease of citrus in Brazil and in several other citrus-producing countries. ACC management is problematic, and bactericides such as copper can be reasonably efficacious but do not completely control...

Antennal and behavioral response of the Asian citrus psyllid (Diaphorina citri Kuwayama) to degradation products of citrus volatiles

USDA-ARS?s Scientific Manuscript database

Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) vectors the bacterial causal pathogen of the deadly citrus disease, Huanglongbing (citrus greening) which is a major threat to citrus industry worldwide. We studied antennal and behavioral responses to principal components of head...

Intraguild interactions among specialised pollen feeders and generalist phytoseiids and their effect on citrus rust mite suppression.

PubMed

Maoz, Yonatan; Gal, Shira; Argov, Yael; Domeratzky, Sylvie; Coll, Moshe; Palevsky, Eric

2016-05-01

Antagonistic interactions among predators with shared prey are thought to hamper their ability to suppress herbivores. Our aim was to quantify intraguild interactions in omnivorous predatory mite assemblages in the presence of pollen, and assess their effect on pest populations. We focused on the following naturally occurring phytoseiid species in Israeli citrus orchards and their ability to suppress a key pest, the citrus rust mite (CRM) Phyllocoptruta oleivora (Eriophyidae): the generalists Amblyseius swirskii and Typhlodromus athiasae and the specialised pollen feeders Iphiseius degenerans, Euseius scutalis, E. stipulatus and E. victoriensis. Evaluations were performed on two spatial scales, tree seedlings and leaf discs. On seedlings, experiments were conducted to quantify the interactions between predators in the presence of pollen and its effects on CRM suppression. On leaf discs, intraguild interactions were studied between pairs of phytoseiid species in the presence of pollen without CRM. On seedlings, the specialised pollen predators were more effective at suppressing CRM populations than the generalist predators. In most cases, the more aggressive intraguild predator was the specialised pollen feeder. Similarly, leaf-disc experiments suggest that in these interactions the specialised pollen feeders tend to be the intraguild predators more often than the intraguild prey. © 2015 Society of Chemical Industry.

Quantitative distribution of 'Candidatus Liberibacter asiaticus' in citrus plants with citrus huanglongbing.

PubMed

Li, Wenbin; Levy, Laurene; Hartung, John S

2009-02-01

Citrus huanglongbing (HLB), or greening disease, is strongly associated with any of three nonculturable gram-negative bacteria belonging to 'Candidatus Liberibacter spp.' 'Ca. Liberibacter spp.' are transmitted by citrus psyllids to all commercial cultivars of citrus. The diseases can be lethal to citrus and have recently become widespread in both São Paulo, Brazil, and Florida, United States, the locations of the largest citrus industries in the world. Asiatic HLB, the form of the disease found in Florida, is associated with 'Ca. Liberibacter asiaticus' and is the subject of this report. The nonculturable nature of the pathogen has hampered research and little is known about the distribution of 'Ca. L. asiaticus' in infected trees. In this study, we have used a quantitative polymerase chain reaction assay to systematically quantify the distribution of 'Ca. L. asiaticus' genomes in tissues of six species of citrus either identified in the field during survey efforts in Florida or propagated in a greenhouse in Beltsville, MD. The populations of 'Ca. L. asiaticus' inferred from the distribution of 16S rDNA sequences specific for 'Ca. L. asiaticus' in leaf midribs, leaf blades, and bark samples varied by a factor of 1,000 among samples prepared from the six citrus species tested and by a factor of 100 between two sweet orange trees tested. In naturally infected trees, above-ground portions of the tree averaged 10(10) 'Ca. L. asiaticus' genomes per gram of tissue. Similar levels of 'Ca. L. asiaticus' genomes were observed in some but not all root samples from the same plants. In samples taken from greenhouse-inoculated trees, levels of 'Ca. L. asiaticus' genomes varied systematically from 10(4) genomes/g at the graft inoculation site to 10(10) genomes/g in some leaf petioles. Root samples from these trees also contained 'Ca. L. asiaticus' at 10(7) genomes/g. In symptomatic fruit tissues, 'Ca. L. asiaticus' genomes were also readily detected and quantified. The highest

78 FR 8435 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids and Fortunella

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-06

... gnidiella (the honeydew moth) and Gymnandrosoma aurantianum (citrus fruit borer); one fungus (Elsino[euml.... APHIS-2011-0060] RIN 0579-AD59 Importation of Fresh Citrus Fruit From Uruguay, Including Citrus Hybrids... Service, USDA. ACTION: Proposed rule. SUMMARY: We are proposing to amend the fruits and vegetables...

Biology of the Huanglongbing vector Diaphorina citri (Hemiptera: Liviidae) on different host plants.

PubMed

Alves, G R; Diniz, A J F; Parra, J R P

2014-04-01

Although many studies have been conducted on the development and reproductive potential of Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae) in different host species, few have evaluated these parameters on different varieties of the same host species. This study evaluated the influence of five commercial varieties of citrus (Citrus spp. L.)--Hamlin, Natal, Pêra, Ponkan, and Valencia-and orange jasmine [Murraya exotica (L.) Jack] on the development of D. citri. Survival rates for the egg stage were highest on orange jasmine (85.7%) and on Valencia (83.3%). The lowest viability of the nymphal stage was also observed on Hamlin, averaging 57.4%. Values for total viability ranged from 65.9 to 32.6%, and were highest on Valencia. The longest egg-adult development time was on Natal, with a mean of 18.4 d; the shortest total development time was on orange jasmine, with a mean of 17.3 d. Based on the fertility life table, the net reproductive rate (Ro) of D. citri was 2.5 times higher when reared on Valencia than on Hamlin. The other parameters (duration of each generation [T], finite rate of increase [lambda], and innate capacity to increase in number [r(m)]) also demonstrated that Valencia is best suited to this insect. The results obtained for the biological parameters and the fertility life table indicate that Valencia and orange jasmine were the most suitable hosts, whereas Hamlin was least suitable for the development of D. citri. These results provide information for the installation of new citrus groves, especially in the choice of varieties to be planted and the location of different varieties within the groves, with a view toward the management of Huanglongbing or HLB.

[R-ALERGO. Allergy-healthy routes in Valencia].

PubMed

Temes Cordovez, Rafael R; Moya Fuero, Alfonso; Martí Garrido, Jaume; Perales Chordá, Carolina; Díaz Palacios, Miguel; Hernández Fernández de Rojas, Dolores

2016-01-01

R-ALERGO is a project developed by researchers from the Universitat Politècnica de València and the Hospital Universitario La Fe (Valencia, Spain). The main objective of the project is to create a mobile application identifying, within the city of Valencia, the most favorable routes for allergic individuals. The application is developed using nine environmental variables with a potential effect on the development of clinical manifestations in allergic individuals. The application combines the use of spatial analysis based on network technology and implemented with a geographic information system software. The first 01 version is under evaluation for a Healthy app hallmark. The next step in this project is to design a clinical validation process to test its usefulness in allergic individuals. Copyright © 2015 SESPAS. Published by Elsevier Espana. All rights reserved.

Citrus Waste Biomass Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karel Grohman; Scott Stevenson

Renewable Spirits is developing an innovative pilot plant bio-refinery to establish the commercial viability of ehtanol production utilizing a processing waste from citrus juice production. A novel process based on enzymatic hydrolysis of citrus processing waste and fermentation of resulting sugars to ethanol by yeasts was successfully developed in collaboration with a CRADA partner, USDA/ARS Citrus and Subtropical Products Laboratory. The process was also successfully scaled up from laboratory scale to 10,000 gal fermentor level.

Microjets of citrus fruit

NASA Astrophysics Data System (ADS)

Smith, Nicholas; Dickerson, Andrew

2017-11-01

The rupture of oil glands in the citrus exocarp is a common experience to the discerning citrus consumer. When peeled, oil cavities housed with the citrus exocarp often rupture outwardly in response to externally applied bending stresses. Bending of the peel compresses the soft material surrounding the glands, the albedo, increasing fluid pressure. Ultimately, the fluid pressure exceeds the failure strength of the outermost membrane, the flavedo. The ensuing high-velocity discharge of oil and exhaustive emptying of oil glands creates a novel method for jetting small quantities of the aromatic and volatile oil. We compare the jetting behavior across five citrus hybrids through high-speed videography and material testing of exocarps. The jetting oil undergoes an initial acceleration surpassing 5,000 gravities, reaching velocities in excess of 10 m/s. Film of citrus jets and mimicking jets in the lab reveal their high level of instability is caused by irregular and non-circular orifice geometry. Through material characterization and bending simulations, we rationalize the combination of material properties necessary to generate the internal gland pressures required for explosive dispersal.

Simple Genetic Distance-Optimized Field Deployments for Clonal Seed Orchards Based on Microsatellite Markers: As a Case of Chinese Pine Seed Orchard.

PubMed

Yuan, Huwei; Niu, Shihui; El-Kassaby, Yousry A; Li, Yue; Li, Wei

2016-01-01

Chinese pine seed orchards are in a period of transition from first-generation to advanced-generations. How to effectively select populations for second-generation seed orchards and significantly increase genetic gain through rational deployment have become major issues. In this study, we examined open- and control-pollinated progeny of the first-generation Chinese pine seed orchards in Zhengning (Gansu Province, China) and Xixian (Shanxi Province, China) to address issues related to phenotypic selection for high volume growth, genetic diversity analysis and genetic distance-based phylogenetic analysis of the selections by simple sequence repeats (SSRs), and phylogenetic relationship-based field deployment for advanced-generation orchards. In total, 40, 28, 20, and 13 superior individuals were selected from the large-scale no-pedigree open-pollinated progeny of Zhengning (ZN-NP), open-pollinated families of Zhengning (ZN-OP), open-pollinated families of Xixian (XX-OP), and control-pollinated families of Xixian, with mean volume dominance ratios of 0.83, 0.15, 0.25, and 0.20, respectively. Phylogenetic relationship analysis of the ZN-NP and XX-OP populations showed that the 40 superior individuals in the ZN-NP selected population belonged to 23 families and could be further divided into five phylogenetic groups, and that families in the same group were closely related. Similarly, 20 families in the XX-OP population were related to varying degrees. Based on these results, we found that second-generation Chinese pine seed orchards in Zhengning and Xixian should adopt a grouped, unbalanced, complete, fixed block design and an unbalanced, incomplete, fixed block design, respectively. This study will provide practical references for applying molecular markers to establishing advanced-generation seed orchards.

Occurrence of methylmercury in Lake Valencia, Venezuela

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaffe, R.; Cai, Y.; West-Thomas, J.

1997-12-31

The presence of mercury in the environment has received renewed attention during recent years. This is in part due to the known human health and ecological effects of the highly toxic organomercury compounds, and to the fact that novel and improved analytical techniques such as atomic fluorescence spectroscopy (AFS) and capillary chromatography with AFS detection, have enhanced significantly the detection of trace amounts of mercury and organo mercurials in environmental samples. Such techniques have allowed for a better understanding of the biogeochemical cycle of mercury in the aquatic environment. This paper reports on the presence of methylmercury in the watermore » column and sediments of a hyper-eutrophic lake. Lake Valencia is a freshwater lake located in North-Central Venezuela`s Aragua Valley. The lake`s surface area covers approximately 350 km{sup 2}, with a mean depth of 19 m and a maximum depth of 41 m. Due to the discharge of waste waters from the cities of Maracay and Valencia, as well as from other smaller villages and agricultural areas in its watershed, Lake Valencia has become hyper-eutrophic. The population of phytoplankton, particularly of blue-green algae, has increased dramatically during the last two decades resulting in anoxic conditions in the lower part of the water column during most of the year. In addition, concentrations of anthropogenic chemicals, including heavy metals, have increased in the Lake during the last four decades. 15 refs., 2 figs.« less

[Service value assessment of orchard ecosystem: a case of Putian City of Fujian].

PubMed

Chen, Jing; Wu, Duan-wang

2011-09-01

Based on the equivalent weight factor of China terrestrial ecosystem service value, and by using ecosystem service value assessment model, this paper evaluated the orchard ecosystem service value in Putian City. In 2002-2008, the orchard ecosystem service value in the City had an overall increasing trend, among which, the service value of gas regulation and water resource conservation had a fluctuation trend of decreased after an initial increase, and that of other functions increased rapidly in 2002-2006 and then developed mildly. The service value of regulation function was higher than that of direct use function, showing that only on the basis of preserving well the functions of ecosystem, could the orchard ecosystem be claimed and used. As most of the orchards in the City are on hills or mountains, the construction and ecological protection of the orchards are obviously disjointed, making the orchards become bare land or other land-use types, resulting in serious soil erosion and degradation, which not only destroyed the orchard ecology, but also gave negative effects on the production efficiency of agriculture. In the future construction of Putian orchards, it should implement comprehensive planning and management of mountain areas, water regions, farm lands, forest lands, and paths, reduce the orchard construction costs by taking advantage of high and new technologies in light of the local conditions and the demands of domestic and foreign markets, and promote the virtuous circle of ecosystem by comprehensive utilization of resources and regulation of biological interaction to make the structure of the orchard ecosystem approached to scientific and rational.

Different adaptation strategies of two citrus scion/rootstock combinations in response to drought stress

PubMed Central

Coelho Filho, Mauricio Antônio; Morillon, Raphaël; Bonatto, Diego; da Silva Gesteira, Abelmon

2017-01-01

Scion/rootstock interaction is important for plant development and for breeding programs. In this context, polyploid rootstocks presented several advantages, mainly in relation to biotic and abiotic stresses. Here we analyzed the response to drought of two different scion/rootstock combinations presenting different polyploidy: the diploid (2x) and autotetraploid (4x) Rangpur lime (Citrus limonia, Osbeck) rootstocks grafted with 2x Valencia Delta sweet orange (Citrus sinensis) scions, named V/2xRL and V/4xRL, respectively. Based on previous gene expression data, we developed an interactomic approach to identify proteins involved in V/2xRL and V/4xRL response to drought. A main interactomic network containing 3,830 nodes and 97,652 edges was built from V/2xRL and V/4xRL data. Exclusive proteins of the V/2xRL and V/4xRL networks (2,056 and 1,001, respectively), as well as common to both networks (773) were identified. Functional clusters were obtained and two models of drought stress response for the V/2xRL and V/4xRL genotypes were designed. Even if the V/2xRL plant implement some tolerance mechanisms, the global plant response to drought was rapid and quickly exhaustive resulting in a general tendency to dehydration avoidance, which presented some advantage in short and strong drought stress conditions, but which, in long terms, does not allow the plant survival. At the contrary, the V/4xRL plants presented a response which strong impacts on development but that present some advantages in case of prolonged drought. Finally, some specific proteins, which presented high centrality on interactomic analysis were identified as good candidates for subsequent functional analysis of citrus genes related to drought response, as well as be good markers of one or another physiological mechanism implemented by the plants. PMID:28545114

A Climatic Classification for Citrus Winter Survival in China.

NASA Astrophysics Data System (ADS)

Shou, Bo Huang

1991-05-01

The citrus tree is susceptible to frost damage. Winter injury to citrus from freezing weather is the major meteorological problem in the northern pail of citrus growing regions in China. Based on meteorological data collected at 120 stations in southern China and on the extent of citrus freezing injury, five climatic regions for citrus winter survival in China were developed. They were: 1) no citrus tree injury. 2) light injury to mandarins (citrus reticulate) or moderate injury to oranges (citrus sinensis), 3) moderate injury to mandarins or heavy injury to oranges, 4) heavy injury to mandarins, and 5) impossible citrus tree growth. This citrus climatic classification was an attempt to provide guidelines for regulation of citrus production, to effectively utilize land and climatic resources, to chose suitable citrus varieties, and to develop methods to prevent injury by freezing.

L-MEB Model Calibration Over the Valencia Anchor Station Area

NASA Astrophysics Data System (ADS)

Lopez-Baeza, E.

2009-04-01

In the framework of ESA's SMOS (Soil Moisture and Ocean Salinity) Mission, several studies are being carried out over different types of land surfaces to study their microwave L-band emission (1.4 GHz). These studies are being integrated in the SMOS emission model (L-MEB, L-band Microwave Emission of the Biosphere, Wigneron et al. 2007), which is the core of the SMOS algorithm for the retrieval of land surface parameters from SMOS data. To contribute to Cal/Val activities at the Valencia Anchor Station (VAS) area (Caudete de las Fuentes, Valencia, Spain), one of the primary validation areas for SMOS land data and products (ESA SMOS Cal/Val AO, Project ID 3252, Lopez-Baeza et al., 2005), a number of experiments have been carried out to study the vegetation influence over the L-band emission proceeding from the soil surface. In the VAS area, a reduced number of homogeneous units have been defined according to the type and use of the soil, mainly, shrubs, vineyards, orchards (almond-and olive-trees) and Mediterranean pine forests. In order to implement the SMOS algorithm over this reference area, it is necessary to characterize and calibrate the L-MEB model for the different cover types. This work is significantly contributing to the definition of the VAS site as a validation area for SMOS land products of the size of a SMOS pixel (SMOS reference pixel). Shrubs and vineyards are the two most significant vegetation types which cover a large percentage of the area and for which very little information at L-band is available in the literature. These two types of vegetation covers have been studied in two separate dedicated experiments under the common name of MELBEX (Mediterranean Ecosystem L-Band characterisation EXperiment). The first one (MELBEX-I) took place over a shrub area characterised by a significant proportion of bare soil with superficial stones. The second one (MELBEX-II) was carried out from March to December 2007 over a large vineyard area. During the time

Monitoring water stress and fruit quality in an orange orchard under regulated deficit irrigation using narrow-band structural and physiological remote sensing indices

NASA Astrophysics Data System (ADS)

Stagakis, S.; González-Dugo, V.; Cid, P.; Guillén-Climent, M. L.; Zarco-Tejada, P. J.

2012-07-01

This paper deals with the monitoring of water status and the assessment of the effect of stress on citrus fruit quality using structural and physiological remote sensing indices. Four flights were conducted over a citrus orchard in 2009 using an unmanned aerial vehicle (UAV) carrying a multispectral camera with six narrow spectral bands in the visible and near infrared. Physiological indices such as the Photochemical Reflectance Index (PRI570), a new structurally robust PRI formulation that uses the 515 nm as the reference band (PRI515), and a chlorophyll ratio (R700/R670) were compared against the Normalized Difference Vegetation Index (NDVI), Renormalized Difference Vegetation Index (RDVI) and Modified Triangular Vegetation Index (MTVI) canopy structural indices for their performance in tracking water status and the effects of sustained water stress on fruit quality at harvest. The irrigation setup in the commercial orchard was compared against a treatment scheduled to satisfy full requirements (based on estimated crop evapotranspiration) using two regulated deficit irrigation (RDI) strategies. The water status of the trees throughout the experiment was monitored with frequent field measurements of stem water potential (Ψx), while titratable acidity (TA) and total soluble solids (TSS) were measured at harvest on selected trees from each irrigation treatment. The high spatial resolution of the multispectral imagery (30 cm pixel size) enabled identification of pure tree crown components, extracting the tree reflectance from shaded, sunlit and aggregated pixels. The physiological and structural indices were then calculated from each tree at the following levels: (i) pure sunlit tree crown, (ii) entire crown, aggregating the within-crown shadows, and (iii) simulating a lower resolution pixel, including tree crown, sunlit and shaded soil pixels. The resulting analysis demonstrated that both PRI formulations were able to track water status, except when water stress

Overexpression of a modified plant thionin enhances disease resistance to citrus canker and huanglongbing (HLB, citrus greening)

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized e...

Tertiary sedimentary history and structure of the Valencia trough (western Mediterranean)

NASA Astrophysics Data System (ADS)

Maillard, A.; Mauffret, A.; Watts, A. B.; Torné, M.; Pascal, G.; Buhl, P.; Pinet, B.

1992-03-01

We present here main results of the Common Depth Point (CDP) data acquired during the Valsis 2 Cruise in 1988 in the Valencia trough. The profiles are tied in with industrial well data and this correlation allows the sedimentary and structural history of the region to be deduced. The Valsis Cruise seismic profiles have been supplemented by a very dense grid of industrial seismic lines and these data permit us to establish an accurate depth to basement map. The formation of the initial grabens, coeval with those of the Gulf of Lions, is related to the Early Miocene opening of the northwestern Mediterranean basin and the Barcelona graben is filled by the same sedimentary layers, including evaporites, as that of the Provençal region. Nevertheless, the Valencia-Catalan grabens have been reactivated by young extensional tectonics which could be a consequence of the convergence of Africa relative to Europe. The Valencia trough is segmented by transfer faults which trend NW-SE. These faults, which have a more accentuated structural expression than the Valencia and Catalonia grabens, may act as transform faults separating the individual Balearic Islands. The transfer faults are in strike with volcanic ridges which have been sampled during the DSDP Leg 13. The dense seismic grid allows us to delineate several widespread volcanic features in the Valencia trough which have been active from the Early Miocene to the Pleistocene. However, we note that the volcanic features are mainly Miocene in age whereas the recent volcanism is restricted to a narrow zone (Columbretes Islands). The compressional tectonics which deformed the Balearic Islands does not appear to extend far towards the North. We delineate the compressional front north of Ibiza, but we failed to determine any thrust or fold north of Mallorca, whereas an extensional tectonics is evident.

Citrus Inventory

NASA Technical Reports Server (NTRS)

1994-01-01

An aerial color infrared (CIR) mapping system developed by Kennedy Space Center enables Florida's Charlotte County to accurately appraise its citrus groves while reducing appraisal costs. The technology was further advanced by development of a dual video system making it possible to simultaneously view images of the same area and detect changes. An image analysis system automatically surveys and photo interprets grove images as well as automatically counts trees and reports totals. The system, which saves both time and money, has potential beyond citrus grove valuation.

Citrus Inventory

NASA Technical Reports Server (NTRS)

1986-01-01

Florida's Charlotte County Property Appraiser is using an aerial color infrared mapping system for inventorying citrus trees for valuation purposes. The ACIR system has significantly reduced the time and manpower required for appraisal. Aerial photographs are taken and interpreted by a video system which makes it possible to detect changes from previous years. Potential problems can be identified. KSC's TU Office has awarded a contract to the Citrus Research and Education Center to adapt a prototype system which would automatically count trees and report totals.

Carnivore use of avocado orchards across an agricultural-wildland gradient

USGS Publications Warehouse

Nogeire, Theresa M.; Davis, Frank W.; Duggan, Jennifer M.; Crooks, Kevin R.; Boydston, Erin E.

2013-01-01

Wide-ranging species cannot persist in reserves alone. Consequently, there is growing interest in the conservation value of agricultural lands that separate or buffer natural areas. The value of agricultural lands for wildlife habitat and connectivity varies as a function of the crop type and landscape context, and quantifying these differences will improve our ability to manage these lands more effectively for animals. In southern California, many species are present in avocado orchards, including mammalian carnivores. We examined occupancy of avocado orchards by mammalian carnivores across agricultural-wildland gradients in southern California with motion-activated cameras. More carnivore species were detected with cameras in orchards than in wildland sites, and for bobcats and gray foxes, orchards were associated with higher occupancy rates. Our results demonstrate that agricultural lands have potential to contribute to conservation by providing habitat or facilitating landscape connectivity.

Weeping dragon, a unique ornamenal citrus

USDA-ARS?s Scientific Manuscript database

‘Weeping Dragon’ is a new ornamental citrus cultivar developed by intercrossing of two unusual and unique citrus types, Poncirus trifoliata cultivated variety (cv.) Flying Dragon, and Citrus sinensis cv. ‘Cipo’. This new hybrid cultivar combines strongly contorted and weeping growth traits in a smal...

Antimicrobial nanoemulsion formulation with improved penetration of foliar spray through citrus leaf cuticles to control citrus Huanglongbing

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB) is one of the most serious citrus diseases that threaten citrus industry worldwide. Because Candidatus Liberibacter asiaticus (Las) resides in citrus phloem, it is difficult to deliver an effective chemical compound into the phloem for control of HLB. In this study, a transcuticu...

Combined use of a new SNP-based assay and multilocus SSR markers to assess genetic diversity of Xylella fastidiosa subsp. pauca infecting citrus and coffee plants.

PubMed

Montes-Borrego, Miguel; Lopes, Joao R S; Jiménez-Díaz, Rafael M; Landa, Blanca B

2015-03-01

Two haplotypes of Xylella fastidiosa subsp. pauca (Xfp) that correlated with their host of origin were identified in a collection of 90 isolates infecting citrus and coffee plants in Brazil, based on a single-nucleotide polymorphism in the gyrB sequence. A new single-nucleotide primer extension (SNuPE) protocol was designed for rapid identification of Xfp according to the host source. The protocol proved to be robust for the prediction of the Xfp host source in blind tests using DNA from cultures of the bacterium, infected plants, and insect vectors allowed to feed on Xfp-infected citrus plants. AMOVA and STRUCTURE analyses of microsatellite data separated most Xfp populations on the basis of their host source, indicating that they were genetically distinct. The combined use of the SNaPshot protocol and three previously developed multilocus SSR markers showed that two haplotypes and distinct isolates of Xfp infect citrus and coffee in Brazil and that multiple, genetically different isolates can be present in a single orchard or infect a single tree. This combined approach will be very useful in studies of the epidemiology of Xfp-induced diseases, host specificity of bacterial genotypes, the occurrence of Xfp host jumping, vector feeding habits, etc., in economically important cultivated plants or weed host reservoirs of Xfp in Brazil and elsewhere. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

78 FR 41259 - Importation of Fresh Citrus Fruit From Uruguay, Including Citrus

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-10

... net increase in the U.S. supply of fresh citrus varieties, as well as some displacement of the... statement in the economic analysis that ``any product displacement that may occur because of the proposed... share (product displacement) for current foreign suppliers of fresh citrus to the United States. U.S...

Evaluation of fumigation and surface seal methods on fumigant emissions in an orchard replant field.

PubMed

Gao, Suduan; Trout, Thomas J; Schneider, Sally

2008-01-01

Soil fumigation is an important management practice for controlling soil pests and enabling successful replanting of orchards. Reducing emissions is required to minimize the possible worker and bystander risk and the contribution of fumigants to the atmosphere as volatile organic compounds that lead to the formation of ground-level ozone. A field trial was conducted in a peach orchard replant field to investigate the effects of fumigation method (shank-injection vs. subsurface drip-application treatments) and surface treatments (water applications and plastic tarps) on emissions of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) from shank-injection of Telone C-35 and drip application of InLine. Treatments included control (no water or soil surface treatment); standard high-density polyethylene (HDPE) tarp, virtually impermeable film (VIF) tarp, and pre-irrigation, all over shank injection; and HDPE tarp over and irrigation with micro-sprinklers before and after the drip application. The highest 1,3-D and CP emission losses over a 2-wk monitoring period were from the control (36% 1,3-D and 30% CP) and HDPE tarp (43% 1,3-D and 17% CP) over shank injection. The pre-irrigation 4 d before fumigation and VIF tarp over shank injection had similar total emission losses (19% 1,3-D and 8-9% CP). The HDPE tarp and irrigations over subsurface drip-application treatments resulted in similar and the lowest emission losses (12-13% 1,3-D, and 2-3% CP). Lower fumigant concentrations in the soil-gas phase were observed with drip-application than in the shank-injection treatments; however, all treatments provided 100% kill to citrus nematodes in bags buried from 30 to 90 cm depth. Pre-irrigation and drip application seem to be effective to minimize emissions of 1,3-D and CP.

Green synthesis of gold nanoparticles using Citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) aqueous extract and its characterization.

PubMed

Sujitha, Mohanan V; Kannan, Soundarapandian

2013-02-01

This study reports the biological synthesis of gold nanoparticles by the reduction of HAuCl(4) by using citrus fruits (Citrus limon, Citrus reticulata and Citrus sinensis) juice extract as the reducing and stabilizing agent. A various shape and size of gold nanoparticles were formed when the ratio of the reactants were altered with respect to 1.0mM chloroauric acid solution. The gold nanoparticles obtained were characterized by UV-visible spectra, transmission electron microscopy (TEM) and X-ray diffraction (XRD). TEM studies showed the particles to be of various shapes and sizes and particle size ranges from 15 to 80 nm. Selected-area electron diffraction (SAED) pattern confirmed fcc phase and crystallinity of the particles. The X-ray diffraction analysis revealed the distinctive facets (111, 200, 220 and 222 planes) of gold nanoparticles. Dynamic light scattering (DLS) studies revealed that the average size for colloid gp(3) of C. limon, C. reticulata and C. sinensis are 32.2 nm, 43.4 nm and 56.7 nm respectively. The DLS graph showed that the particles size was larger and more polydispersed compared to the one observed by TEM due to the fact that the measured size also includes the bio-organic compounds enveloping the core of the Au NPs. Zeta potential value for gold nanoparticles obtained from colloid gp(3) of C. limon, C. reticulata and C. sinensis are -45.9, -37.9 and -31.4 respectively indicating the stability of the synthesized nanoparticles. Herein we propose a novel, previously unexploited method for the biological syntheses of polymorphic gold nanoparticles with potent biological applications. Copyright © 2012 Elsevier B.V. All rights reserved.

[Variation characteristics of soil moisture in apple orchards of Luochuan County, Shaanxi Province of Northwest China].

PubMed

Wang, Yan-Ping; Han, Ming-Yu; Zhang, Lin-Sen; Dang, Yong-Jian; Qu, Jun-Tao

2012-03-01

To have an overall understanding on the soil moisture characteristics in the apple orchards of Luochuan County can not only provide theoretical basis for selecting apple orchard sites, choosing the best root-stock combination, and improving the soil water management, but also has reference importance in increasing the productive efficiency of our apple orchards. In this study, a fixed-point continuous monitoring was conducted on the overall soil moisture environment and the variation characteristics of soil moisture in the County apple orchards differed in age class, stand type, and tree type (standard or dwarfed). For the apple orchards in the County, the rhizosphere (0-200 cm) soils of most apple trees were water-deficient, and the deficit in 0-60 cm soil layer was less than that in 60-200 cm layer. During growth season, the water storage in 0-60 cm soil layer had the same variation trend as the rainfall pattern. The relative soil moisture content in most orchards was less than 60% , and seasonal drought was quite severe. The coefficient of variation of soil moisture content decreased with soil depth. With the increasing age of the orchards, soil water storage decreased. At the same planting density, the orchards with dwarfed trees had more water storage in 0-5 m soil layer than the orchards with standard trees. However, when the orchards were planted with dwarfed trees at a higher density, the soil water storage in the orchards with dwarfed trees was lesser than that in the standard orchards. The mature orchards on highland had the highest soil moisture content, followed by the mature orchards on flat land, and on terraced land. Tree density had great effects on the soil moisture content. When the tree density was the same, planting dwarfed trees could decrease the water consumption, and increase the soil moisture content significantly. To decrease the planting density through the removal of trees would be an effective way to maintain the soil water balance of

Seasonal Population Dynamics of Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) in Sweet Orange Trees Maintained under Continuous Deficit Irrigation

USDA-ARS?s Scientific Manuscript database

A two-year study was conducted in a citrus orchard [Citrus sinensis (L.) Osbeck cv. ‘Valencia’] to determine influence of plant water stress on population dynamics of glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar). Experimental treatments included irrigation at 100% of the crop...

[Climatic suitability of citrus in subtropical China].

PubMed

Duan, Hai-Lai; Qian, Huai-Sui; Li, Ming-Xia; Du, Yao-Dong

2010-08-01

By applying the theories of ecological suitability and the methods of fuzzy mathematics, this paper established a climatic suitability model for citrus, calculated and evaluated the climatic suitability and its spatiotemporal differences for citrus production in subtropical China, and analyzed the climatic suitability of citrus at its different growth stages and the mean climatic suitability of citrus in different regions of subtropical China. The results showed that the citrus in subtropical China had a lower climatic suitability and a higher risk at its flower bud differentiation stage, budding stage, and fruit maturity stage, but a higher climatic suitability and a lower risk at other growth stages. Cold damage and summer drought were the key issues affecting the citrus production in subtropical China. The citrus temperature suitability represented a latitudinal zonal pattern, i. e., decreased with increasing latitude; its precipitation suitability was high in the line of "Sheyang-Napo", medium in the southeast of the line, low in the northwest of the line, and non in high mountainous area; while the sunlight suitability was in line with the actual duration of sunshine, namely, higher in high-latitude areas than in low-latitude areas, and higher in high-altitude areas than in plain areas. Limited by temperature factor, the climatic suitability was in accordance with temperature suitability, i. e., south parts had a higher suitability than north parts, basically representing latitudinal zonal pattern. From the analysis of the inter-annual changes of citrus climatic suitability, it could be seen that the citrus climatic suitability in subtropical China was decreasing, and had obvious regional differences, suggesting that climate change could bring about the changes in the regions suitable for citrus production and in the key stages of citrus growth.

Work, rice and malaria in Valencia in the XVIIIth century.

PubMed

Riera Palmero, J

1994-01-01

This study, prepared with documentary sources from archives, focuses on one of the most serious health problems in Spain in the age of Enlightenment; that is, the pernicious endemics of malaria in the humid Mediterranean zones. Based on material from the General Archives of Simancas, the author studies the health polemic between the partisans and detractors of rice cultivation in the swampy bogs of the Turia and Júcar river areas. To these considerations on Valencia's agricultural expansion in the 18th century is added a documented study on malaria in the ancient kingdom of Valencia, a theme which underlies this historiographic contribution.

NuMex-02- A High oleic Valencia peanut with partial resistance to Sclerotinia blight

USDA-ARS?s Scientific Manuscript database

NuMex-02 is a high oleic Valencia peanut (Arachis hypogaea L., subsp. fastigiata var. fastigiata) cultivar developed by the New Mexico Agricultural Experiment Station, Clovis, New Mexico. NuMex-02 originated from a cross made between NM Valencia A and OLin. Pedigree selection was practiced based on...

Carbon sequestration by fruit trees--Chinese apple orchards as an example.

PubMed

Wu, Ting; Wang, Yi; Yu, Changjiang; Chiarawipa, Rawee; Zhang, Xinzhong; Han, Zhenhai; Wu, Lianhai

2012-01-01

Apple production systems are an important component in the Chinese agricultural sector with 1.99 million ha plantation. The orchards in China could play an important role in the carbon (C) cycle of terrestrial ecosystems and contribute to C sequestration. The carbon sequestration capability in apple orchards was analyzed through identifying a set of potential assessment factors and their weighting factors determined by a field model study and literature. The dynamics of the net C sink in apple orchards in China was estimated based on the apple orchard inventory data from 1990s and the capability analysis. The field study showed that the trees reached the peak of C sequestration capability when they were 18 years old, and then the capability began to decline with age. Carbon emission derived from management practices would not be compensated through C storage in apple trees before reaching the mature stage. The net C sink in apple orchards in China ranged from 14 to 32 Tg C, and C storage in biomass from 230 to 475 Tg C between 1990 and 2010. The estimated net C sequestration in Chinese apple orchards from 1990 to 2010 was equal to 4.5% of the total net C sink in the terrestrial ecosystems in China. Therefore, apple production systems can be potentially considered as C sinks excluding the energy associated with fruit production in addition to provide fruits.

Phagostimulants for the Asian citrus psyllid also elicit volatile release from citrus leaves

USDA-ARS?s Scientific Manuscript database

Chemical cues that elicit orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. We identified an optimal blend ratio of formic and acetic acids that stimulate...

Yield and quality responses of citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to compound fertilizers*

PubMed Central

Wang, Rui; Shi, Xue-gen; Wei, You-zhang; Yang, Xiao-e; Uoti, Juhani

2006-01-01

Experiments were carried out with citrus (Citrus reticulate) and tea (Podocarpus fleuryi Hickel.) to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P, K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51, 0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea. Optimal rates of compound fertilizers were recommended for both crops. PMID:16909469

Spectral sensitivity of the Asian citrus psyllid, Diaphorina citri

USDA-ARS?s Scientific Manuscript database

The Asian Citrus psyllid, Diaphorina citri, as a vector of the bacteria causing citrus greening, is considered one of the most important citrus pests globally. Movement of infected psyllids onto uninfected young citrus remains a key concern for the maintenance of citrus production. Attraction of d...

Citrus breeding, genetics and genomics in Japan

PubMed Central

Omura, Mitsuo; Shimada, Takehiko

2016-01-01

Citrus is one of the most cultivated fruits in the world, and satsuma mandarin (Citrus unshiu Marc.) is a major cultivated citrus in Japan. Many excellent cultivars derived from satsuma mandarin have been released through the improvement of mandarins using a conventional breeding method. The citrus breeding program is a lengthy process owing to the long juvenility, and it is predicted that marker-assisted selection (MAS) will overcome the obstacle and improve the efficiency of conventional breeding methods. To promote citrus molecular breeding in Japan, a genetic mapping was initiated in 1987, and the experimental tools and resources necessary for citrus functional genomics have been developed in relation to the physiological analysis of satsuma mandarin. In this paper, we review the progress of citrus breeding and genome researches in Japan and report the studies on genetic mapping, expression sequence tag cataloguing, and molecular characterization of breeding characteristics, mainly in terms of the metabolism of bio-functional substances as well as factors relating to, for example, fruit quality, disease resistance, polyembryony, and flowering. PMID:27069387

Comparison of antifungal activities of Vietnamese citrus essential oils.

PubMed

Van Hung, Pham; Chi, Pham Thi Lan; Phi, Nguyen Thi Lan

2013-03-01

Citrus essential oils (EOs) are volatile compounds from citrus peels and widely used in perfumes, cosmetics, soaps and aromatherapy. In this study, inhibition of citrus EOs extracted from Vietnamese orange (Citrus sinensis), mandarin (Citrus reticulata Blanco), pomelo (Citrus grandis Osbeck) and lime (Citrus aurantifolia Swingle) on the growth of plant pathogenic fungi, Mucor hiemalis, Penicillium expansum and Fusarium proliferatum was investigated. The EOs of the citrus peels were obtained by cold-pressing method and the antifungal activity of EOs was evaluated using the agar dilution method. The results show that the EOs had significant antifungal activity. Lime EO was the best inhibitor of M. hiemalis and F. proliferatum while pomelo EO was the most effective against P. expansum. These results indicate that citrus EOs can be used as antifungal natural products in the food, pharmaceutical and cosmetic industries.

Brain cancer and pesticide relationship in orchard farmers of Kashmir

PubMed Central

Bhat, Abdul Rashid; Wani, Muhammed Afzal; Kirmani, A. R.

2010-01-01

Background: The increasing trend in the incidence of primary malignant brain tumors in orchard farmers and their families in Kashmir. Aim: To determine the relationship between the patients of primary malignant brain tumors and their occupation. Materials and Methods: Retrospectively, case files along with death certificates of 432 patients of primary malignant brain tumors and 457 controls (non-tumor neurologic diseases), admitted for treatment simultaneously over a period of 4 years from January 2005 to December 2008, to the Neurosurgery, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Kashmir, were studied. Follow-up and family interaction was established. Results: Analysis revealed that 90.04% (389 out of 432) patients were orchard farm workers, orchard residents and orchard playing children exposed to the high levels of multiple types of neurotoxic and carcinogenic (chlorpyriphos, dimethoate, mancozeb and captan) chemicals for more than 10 years [relative risk (RR) = 10.6; odds ratio (OR) = >10; 95% confidence interval (CI) = >25-40]. The 9.96% (43 out of 432) patients were not exposed to pesticides. On the other hand, only 19 patients out of 457 controls had recorded history of pesticide exposure and 438 were unrelated to pesticides. Out of 389 patients, 71.7% (279 out of 389) were males and 28.3% (110 out of 389), including six members of three families, were females (one male child). Conclusion: All orchard-related 389 patients had high-grade tumors as compared to the non-pesticide tumors. Mortality in pesticide-exposed tumors was 12%. The higher or upper-normal levels of serum cholinesterase (AChE) were observed in 54.7% (213 out of 389) patients and decreased levels were found in only 45.3% (176 out of 389) orchard-related patients (RR = 19.4; OR = >5; 95% CI = >1-10). Although serum AChE levels were a routine investigation in malignant brain tumors, this was not a routine in other neurological conditions (hospitalized controls). The familial

Brain cancer and pesticide relationship in orchard farmers of Kashmir.

PubMed

Bhat, Abdul Rashid; Wani, Muhammed Afzal; Kirmani, A R

2010-09-01

The increasing trend in the incidence of primary malignant brain tumors in orchard farmers and their families in Kashmir. To determine the relationship between the patients of primary malignant brain tumors and their occupation. Retrospectively, case files along with death certificates of 432 patients of primary malignant brain tumors and 457 controls (non-tumor neurologic diseases), admitted for treatment simultaneously over a period of 4 years from January 2005 to December 2008, to the Neurosurgery, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Kashmir, were studied. Follow-up and family interaction was established. Analysis revealed that 90.04% (389 out of 432) patients were orchard farm workers, orchard residents and orchard playing children exposed to the high levels of multiple types of neurotoxic and carcinogenic (chlorpyriphos, dimethoate, mancozeb and captan) chemicals for more than 10 years [relative risk (RR) = 10.6; odds ratio (OR) = >10; 95% confidence interval (CI) = >25-40]. The 9.96% (43 out of 432) patients were not exposed to pesticides. On the other hand, only 19 patients out of 457 controls had recorded history of pesticide exposure and 438 were unrelated to pesticides. Out of 389 patients, 71.7% (279 out of 389) were males and 28.3% (110 out of 389), including six members of three families, were females (one male child). All orchard-related 389 patients had high-grade tumors as compared to the non-pesticide tumors. Mortality in pesticide-exposed tumors was 12%. The higher or upper-normal levels of serum cholinesterase (AChE) were observed in 54.7% (213 out of 389) patients and decreased levels were found in only 45.3% (176 out of 389) orchard-related patients (RR = 19.4; OR = >5; 95% CI = >1-10). Although serum AChE levels were a routine investigation in malignant brain tumors, this was not a routine in other neurological conditions (hospitalized controls). The familial gliomas have shown an emerging trend in the orchard residents of

Plant water stress effects on the net dispersal rate of the insect vector Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) and movement of its egg parasitoid, Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae)

USDA-ARS?s Scientific Manuscript database

Homalodisca vitripennis, one of the main vectors of Xylella fastidiosa, is associated with citrus plantings in California, USA. Infested citrus orchards act as a source of vectors to adjacent vineyards where X. fastidiosa causes Pierce’s disease (PD). An analysis of the pattern and rate of movement ...

Changes in Anthocyanin Production during Domestication of Citrus.

PubMed

Butelli, Eugenio; Garcia-Lor, Andrés; Licciardello, Concetta; Las Casas, Giuseppina; Hill, Lionel; Recupero, Giuseppe Reforgiato; Keremane, Manjunath L; Ramadugu, Chandrika; Krueger, Robert; Xu, Qiang; Deng, Xiuxin; Fanciullino, Anne-Laure; Froelicher, Yann; Navarro, Luis; Martin, Cathie

2017-04-01

Mandarin ( Citrus reticulata ), citron ( Citrus medica ), and pummelo ( Citrus maxima ) are important species of the genus Citrus and parents of the interspecific hybrids that constitute the most familiar commercial varieties of Citrus : sweet orange, sour orange, clementine, lemon, lime, and grapefruit. Citron produces anthocyanins in its young leaves and flowers, as do species in genera closely related to Citrus , but mandarins do not, and pummelo varieties that produce anthocyanins have not been reported. We investigated the activity of the Ruby gene, which encodes a MYB transcription factor controlling anthocyanin biosynthesis, in different accessions of a range of Citrus species and in domesticated cultivars. A white mutant of lemon lacks functional alleles of Ruby , demonstrating that Ruby plays an essential role in anthocyanin production in Citrus Almost all the natural variation in pigmentation by anthocyanins in Citrus species can be explained by differences in activity of the Ruby gene, caused by point mutations and deletions and insertions of transposable elements. Comparison of the allelic constitution of Ruby in different species and cultivars also helps to clarify many of the taxonomic relationships in different species of Citrus , confirms the derivation of commercial varieties during domestication, elucidates the relationships within the subgenus Papeda , and allows a new genetic classification of mandarins. © 2017 American Society of Plant Biologists. All Rights Reserved.

Primary and secondary pesticide drift profiles from a peach orchard.

PubMed

Zivan, Ohad; Bohbot-Raviv, Yardena; Dubowski, Yael

2017-06-01

Atmospheric drift is considered a major loss path of pesticide from target areas, but there is still a large gap of knowledge regarding this complex phenomenon. Pesticide drift may occur during application (Primary drift) and after it (Secondary drift). The present study focuses on primary and secondary drift from ground applications in peach orchard (tree height of 3 m), under Mediterranean climate. Detailed and prolonged vertical drift profiles at close proximity to orchard are presented, together with detailed measurements of key meteorological parameters. The effect of volatility on drift was also studied by simultaneously applying two pesticides that differ in their volatility. Drifting airborne pesticides were detected both during and after applications at sampling distances of 7 and 20 m away from orchard edge. Concentrations ranged between hundreds ng m -3 to a few μg m -3 and showed clear decrease with time and with upwind conditions. Almost no decline in concentrations with height was observed up to thrice canopy height (i.e., 10 m). These homogeneous profiles indicate strong mixing near orchard and are in line with the unstable atmospheric conditions that prevailed during measurements. While air concentrations during pesticide application were higher than after it, overall pesticide load drifted from the orchard during primary and secondary drift are comparable. To the best of our knowledge this is the first work to show such large vertical dispersion and long duration of secondary drift following ground application in orchards. The obtained information indicates that secondary drift should not be neglected in exposure and environmental impact estimations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enumerative and binomial sampling plans for citrus mealybug (Homoptera: pseudococcidae) in citrus groves.

PubMed

Martínez-Ferrer, María Teresa; Ripollés, José Luís; Garcia-Marí, Ferran

2006-06-01

The spatial distribution of the citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae), was studied in citrus groves in northeastern Spain. Constant precision sampling plans were designed for all developmental stages of citrus mealybug under the fruit calyx, for late stages on fruit, and for females on trunks and main branches; more than 66, 286, and 101 data sets, respectively, were collected from nine commercial fields during 1992-1998. Dispersion parameters were determined using Taylor's power law, giving aggregated spatial patterns for citrus mealybug populations in three locations of the tree sampled. A significant relationship between the number of insects per organ and the percentage of occupied organs was established using either Wilson and Room's binomial model or Kono and Sugino's empirical formula. Constant precision (E = 0.25) sampling plans (i.e., enumerative plans) for estimating mean densities were developed using Green's equation and the two binomial models. For making management decisions, enumerative counts may be less labor-intensive than binomial sampling. Therefore, we recommend enumerative sampling plans for the use in an integrated pest management program in citrus. Required sample sizes for the range of population densities near current management thresholds, in the three plant locations calyx, fruit, and trunk were 50, 110-330, and 30, respectively. Binomial sampling, especially the empirical model, required a higher sample size to achieve equivalent levels of precision.

Carbon Sequestration by Fruit Trees - Chinese Apple Orchards as an Example

PubMed Central

Wu, Ting; Wang, Yi; Yu, Changjiang; Chiarawipa, Rawee; Zhang, Xinzhong; Han, Zhenhai; Wu, Lianhai

2012-01-01

Apple production systems are an important component in the Chinese agricultural sector with 1.99 million ha plantation. The orchards in China could play an important role in the carbon (C) cycle of terrestrial ecosystems and contribute to C sequestration. The carbon sequestration capability in apple orchards was analyzed through identifying a set of potential assessment factors and their weighting factors determined by a field model study and literature. The dynamics of the net C sink in apple orchards in China was estimated based on the apple orchard inventory data from 1990s and the capability analysis. The field study showed that the trees reached the peak of C sequestration capability when they were 18 years old, and then the capability began to decline with age. Carbon emission derived from management practices would not be compensated through C storage in apple trees before reaching the mature stage. The net C sink in apple orchards in China ranged from 14 to 32 Tg C, and C storage in biomass from 230 to 475 Tg C between 1990 and 2010. The estimated net C sequestration in Chinese apple orchards from 1990 to 2010 was equal to 4.5% of the total net C sink in the terrestrial ecosystems in China. Therefore, apple production systems can be potentially considered as C sinks excluding the energy associated with fruit production in addition to provide fruits. PMID:22719974

Contamination of apple orchard soils and fruit trees with copper-based fungicides: sampling aspects.

PubMed

Wang, Quanying; Liu, Jingshuang; Liu, Qiang

2015-01-01

Accumulations of copper in orchard soils and fruit trees due to the application of Cu-based fungicides have become research hotspots. However, information about the sampling strategies, which can affect the accuracy of the following research results, is lacking. This study aimed to determine some sampling considerations when Cu accumulations in the soils and fruit trees of apple orchards are studied. The study was conducted in three apple orchards from different sites. Each orchard included two different histories of Cu-based fungicides usage, varying from 3 to 28 years. Soil samples were collected from different locations varying with the distances from tree trunk to the canopy drip line. Fruits and leaves from the middle heights of tree canopy at two locations (outer canopy and inner canopy) were collected. The variation in total soil Cu concentrations between orchards was much greater than the variation within orchards. Total soil Cu concentrations had a tendency to increase with the increasing history of Cu-based fungicides usage. Moreover, total soil Cu concentrations had the lowest values at the canopy drip line, while the highest values were found at the half distances between the trunk and the canopy drip line. Additionally, Cu concentrations of leaves and fruits from the outer parts of the canopy were significantly higher than from the inner parts. Depending on the findings of this study, not only the between-orchard variation but also the within-orchard variation should be taken into consideration when conducting future soil and tree samplings in apple orchards.

Degradation products of citrus volatile organic compounds (VOCs) acting as phagostimulants that increase probing behavior of Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

Volatile phytochemicals play a role in orientation by phytophagous insects. We studied antennal and behavioral responses of the Asian citrus psyllid, Diaphorina citri Kuwayama, vector of the citrus greening disease pathogen. Little or no response to citrus leaf volatiles was detected by electroanten...

Optimal Path Planning Program for Autonomous Speed Sprayer in Orchard Using Order-Picking Algorithm

NASA Astrophysics Data System (ADS)

Park, T. S.; Park, S. J.; Hwang, K. Y.; Cho, S. I.

This study was conducted to develop a software program which computes optimal path for autonomous navigation in orchard, especially for speed sprayer. Possibilities of autonomous navigation in orchard were shown by other researches which have minimized distance error between planned path and performed path. But, research of planning an optimal path for speed sprayer in orchard is hardly founded. In this study, a digital map and a database for orchard which contains GPS coordinate information (coordinates of trees and boundary of orchard) and entity information (heights and widths of trees, radius of main stem of trees, disease of trees) was designed. An orderpicking algorithm which has been used for management of warehouse was used to calculate optimum path based on the digital map. Database for digital map was created by using Microsoft Access and graphic interface for database was made by using Microsoft Visual C++ 6.0. It was possible to search and display information about boundary of an orchard, locations of trees, daily plan for scattering chemicals and plan optimal path on different orchard based on digital map, on each circumstance (starting speed sprayer in different location, scattering chemicals for only selected trees).

Profiling of bioactive compounds in cultivars of Runner and Valencia peanut market-types using liquid chromatography/APCI mass spectrometry.

PubMed

Chukwumah, Yvonne; Walker, Lloyd; Vogler, Bernhard; Verghese, Martha

2012-05-01

Peanuts are classified into four market-types (Runners, Spanish, Virginia and Valencia). Studies on their phytochemical composition have focused mainly on market-types other than Valencia. The objectives of this study are to evaluate the phytochemical composition of cultivars of Valencia and Runner market-types. Extracts of 25 peanut cultivars of Runner and Valencia market-types were analysed using HPLC-DAD-MS analysis. Results showed major differences in UV profile of the market-types. A major peak with m/z 317 identified as isorhamnetin was present only in Valencia cultivars while its glycoside (isorhamnetin-3-O-rutinoside) having m/z 625 was identified in both market-types. Genistein, daidzein, rutin, quercetin and trans-resveratrol were also identified and quantified. Genistein and daidzein concentrations (0.03mg/100g) were similar in both market-types. trans-Resveratrol and rutin were significantly (p<0.05) higher in Runner cultivars while quercetin was 10-fold higher (0.60±0.04mg/100g) in Valencia cultivars making them a better source of this phytochemical. Copyright © 2011 Elsevier Ltd. All rights reserved.

Mapping the genetic and tissular diversity of 64 phenolic compounds in Citrus species using a UPLC–MS approach

PubMed Central

Durand-Hulak, Marie; Dugrand, Audray; Duval, Thibault; Bidel, Luc P. R.; Jay-Allemand, Christian; Froelicher, Yann; Bourgaud, Frédéric; Fanciullino, Anne-Laure

2015-01-01

Background and Aims Phenolic compounds contribute to food quality and have potential health benefits. Consequently, they are an important target of selection for Citrus species. Numerous studies on this subject have revealed new molecules, potential biosynthetic pathways and linkage between species. Although polyphenol profiles are correlated with gene expression, which is responsive to developmental and environmental cues, these factors are not monitored in most studies. A better understanding of the biosynthetic pathway and its regulation requires more information about environmental conditions, tissue specificity and connections between competing sub-pathways. This study proposes a rapid method, from sampling to analysis, that allows the quantitation of multiclass phenolic compounds across contrasting tissues and cultivars. Methods Leaves and fruits of 11 cultivated citrus of commercial interest were collected from adult trees grown in an experimental orchard. Sixty-four phenolic compounds were simultaneously quantified by ultra-high-performance liquid chromatography coupled with mass spectrometry. Key Results Combining data from vegetative tissues with data from fruit tissues improved cultivar classification based on polyphenols. The analysis of metabolite distribution highlighted the massive accumulation of specific phenolic compounds in leaves and the external part of the fruit pericarp, which reflects their involvement in plant defence. The overview of the biosynthetic pathway obtained confirmed some regulatory steps, for example those catalysed by rhamnosyltransferases. The results suggest that three other steps are responsible for the different metabolite profiles in ‘Clementine’ and ‘Star Ruby’ grapefruit. Conclusions The method described provides a high-throughput method to study the distribution of phenolic compounds across contrasting tissues and cultivars in Citrus, and offers the opportunity to investigate their regulation and physiological

Patterns and Drivers of Scattered Tree Loss in Agricultural Landscapes: Orchard Meadows in Germany (1968-2009)

PubMed Central

Plieninger, Tobias; Levers, Christian; Mantel, Martin; Costa, Augusta; Schaich, Harald; Kuemmerle, Tobias

2015-01-01

Scattered trees support high levels of farmland biodiversity and ecosystem services in agricultural landscapes, but they are threatened by agricultural intensification, urbanization, and land abandonment. This study aimed to map and quantify the decline of orchard meadows (scattered fruit trees of high nature conservation value) for a region in Southwestern Germany for the 1968 2009 period and to identify the driving forces of this decline. We derived orchard meadow loss from 1968 and 2009 aerial images and used a boosted regression trees modelling framework to assess the relative importance of 18 environmental, demographic, and socio-economic variables to test five alternative hypothesis explaining orchard meadow loss. We found that orchard meadow loss occurred in flatter areas, in areas where smaller plot sizes and fragmented orchard meadows prevailed, and in areas near settlements and infrastructure. The analysis did not confirm that orchard meadow loss was higher in areas where agricultural intensification was stronger and in areas of lower implementation levels of conservation policies. Our results demonstrated that the influential drivers of orchard meadow loss were those that reduce economic profitability and increase opportunity costs for orchards, providing incentives for converting orchard meadows to other, more profitable land uses. These insights could be taken up by local- and regional-level conservation policies to identify the sites of persistent orchard meadows in agricultural landscapes that would be prioritized in conservation efforts. PMID:25932914

Comparison of carotenoid accumulation and biosynthetic gene expression between Valencia and Rohde Red Valencia sweet oranges.

PubMed

Wei, Xu; Chen, Chunxian; Yu, Qibin; Gady, Antoine; Yu, Yuan; Liang, Guolu; Gmitter, Frederick G

2014-10-01

Carotenoid accumulation and biosynthetic gene expression levels during fruit maturation were compared between ordinary Valencia (VAL) and its more deeply colored mutant Rohde Red Valencia orange (RRV). The two cultivars exhibited different carotenoid profiles and regulatory mechanisms in flavedo and juice sacs, respectively. In flavedo, there was uncoordinated carotenoid accumulation and gene expression in RRV during green stages, which might be related to the expression of certain gene(s) in the MEP (methylerythritol phosphate) pathway. The carotenoid biosynthesis pathway shifting from α,β-xanthophylls to β,β-xanthophylls synthesis occurred in RRV earlier than VAL during orange stages. In juice sacs, the low carotenoid content in both cultivars coincided with low expression of LCYE-Contig03 and LCYE-Contig24 during green stages, suggesting LCYE might be a limiting step for carotenoid accumulation. VAL mainly accumulated violaxanthin, but RRV accumulated β-cryptoxanthin and violaxanthin during orange stages, which corresponded to differences in juice color. Several upstream genes (PDS-Contig17, LCYB-Contig19, and ZDS members) and a downstream gene (ZEP) were expressed at higher levels in RRV than VAL, which might be responsible for greater accumulation of β-cryptoxanthin and violaxanthin in RRV, respectively. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The aconitate hydratase family from Citrus

PubMed Central

2010-01-01

Background Research on citrus fruit ripening has received considerable attention because of the importance of citrus fruits for the human diet. Organic acids are among the main determinants of taste and organoleptic quality of fruits and hence the control of fruit acidity loss has a strong economical relevance. In citrus, organic acids accumulate in the juice sac cells of developing fruits and are catabolized thereafter during ripening. Aconitase, that transforms citrate to isocitrate, is the first step of citric acid catabolism and a major component of the citrate utilization machinery. In this work, the citrus aconitase gene family was first characterized and a phylogenetic analysis was then carried out in order to understand the evolutionary history of this family in plants. Gene expression analyses of the citrus aconitase family were subsequently performed in several acidic and acidless genotypes to elucidate their involvement in acid homeostasis. Results Analysis of 460,000 citrus ESTs, followed by sequencing of complete cDNA clones, identified in citrus 3 transcription units coding for putatively active aconitate hydratase proteins, named as CcAco1, CcAco2 and CcAco3. A phylogenetic study carried on the Aco family in 14 plant species, shows the presence of 5 Aco subfamilies, and that the ancestor of monocot and dicot species shared at least one Aco gene. Real-time RT-PCR expression analyses of the three aconitase citrus genes were performed in pulp tissues along fruit development in acidic and acidless citrus varieties such as mandarins, oranges and lemons. While CcAco3 expression was always low, CcAco1 and CcAco2 genes were generally induced during the rapid phase of fruit growth along with the maximum in acidity and the beginning of the acid reduction. Two exceptions to this general pattern were found: 1) Clemenules mandarin failed inducing CcAco2 although acid levels were rapidly reduced; and 2) the acidless "Sucreña" orange showed unusually high levels

Louisa May Alcott's Orchard House

Science.gov Websites

and Her Father! Buy the book from Orchard House Read more about John Matteson's award here Louisa May comments about this site, click to use our Online Guest Book All archival photographs © Louisa May Online Guest Book

Phytophagous mite populations on Tahiti lime, Citrus latifolia, under induced drought conditions.

PubMed

Quiros-Gonzalez, M

2000-01-01

In the north-western region of Venezuela, Phyllocoptruta oleivora, Tetranychus mexicanus and Brevipalpus phoenicis are common plant-feeding mites on leaves, fruits and branches of Tahiti lime, Citrus latifolia. The population dynamics of these herbivores are affected by many factors, such as weekly treatments with wettable sulphur, particularly during the wet season, maintenance pruning of plants, irrigation with microsprinklers, induction of water stress by withholding irrigation and biotic and abiotic environmental factors. During October 1994-January 1995, 31 trees in a commercial orchard were sampled weekly in order to describe population fluctuations of plant-feeding mites (mean number of mites per leaf or fruit), before (4 weeks) and after (4 weeks) a period of 6 weeks of drought stress (no irrigation). The population density of P. oleivora increased progressively during the last 3 weeks of the irrigation period and reached a maximum of 24 mites per fruit. In contrast, the populations of the other two species, T. mexicanus and B. phoenicis, remained at the same low density as before the withholding-irrigation period. After 6 weeks without irrigation, only T. mexicanus increased, to a high mean value of 11 mites per leaf. The withholding-irrigation practice appears to affect the population size of P. oleivora towards the end of this period and that of T. mexicanus at the beginning of the re-establishment of the water supply. The highest proportion of trees (32%) was infested by T. mexicanus after the withholding-irrigation period, when irrigation was resumed, whereas the highest levels of infestation of trees by P. oleivora and B. phoenicis were 16 and 10%, respectively, during the last week of the water-stress period. Although factors affecting the dynamics of the mites in the orchard are likely to be complex, irrigation management apparently plays an important role.

Recent introduction and recombination in Colletotrichum acutatum populations associated with citrus postbloom fruit drop epidemics in São Paulo, Brazil.

PubMed

Ciampi-Guillardi, Maisa; Baldauf, Cristina; Souza, Anete Pereira; Silva-Junior, Geraldo José; Amorim, Lilian

2014-07-01

Citrus crops in São Paulo State, Brazil, have been severely affected by postbloom fruit drop disease (PFD), which is caused by Colletotrichum acutatum. This disease leads to the drop of up to 100% of young fruits. Previous studies have assumed that this pathogen exhibits a clonal reproductive mode, although no population genetic studies have been conducted so far. Thus, the genetic structure of six C. acutatum populations from sweet orange orchards showing PFD symptoms was determined using nine microsatellite markers, enabling inference on predominant mode of reproduction. C. acutatum populations exhibit a nearly panmictic genetic structure and a high degree of admixture, indicating either ongoing contemporary gene flow at a regional scale or a recent introduction from a common source, since this pathogen was introduced in Brazil only very recently. Sharing haplotypes among orchards separated by 400 km suggests the natural dispersal of fungal propagules, with the possible involvement of pollinators. A significant population expansion was detected, which was consistent with an increase in host density associated with crop expansion toward new areas across the state. Findings of moderate to high levels of haplotypic diversity and gametic equilibrium suggest that recombination might play an important role in these pathogen populations, possibly via parasexual reproduction or a cryptic sexual cycle. This study provides additional tools for epidemiological studies of C. acutatum to improve prevention and management strategies for this disease.

Valencia Community College Educational Technology Plan, 2000-2004.

ERIC Educational Resources Information Center

Valencia Community Coll., Orlando, FL.

The purpose of the Educational Technology Plan is to provide a collaborative framework to address the institutional assessment, prioritization, implementation, and resource allocation associated with technology issues at Valencia Community College (Florida). The plan has been integrated with the college's Comprehensive Strategic Plan goals and…

Wildflower Plantings Do Not Compete With Neighboring Almond Orchards for Pollinator Visits.

PubMed

Lundin, Ola; Ward, Kimiora L; Artz, Derek R; Boyle, Natalie K; Pitts-Singer, Theresa L; Williams, Neal M

2017-06-01

The engineering of flowering agricultural field borders has emerged as a research and policy priority to mitigate threats to pollinators. Studies have, however, rarely addressed the potential that flowering field borders might compete with neighboring crops for pollinator visits if they both are in bloom at the same time, despite this being a concern expressed by growers. We evaluated how wildflower plantings added to orchard borders in a large (512 ha) commercial almond orchard affected honey bee and wild bee visitation to orchard borders and the crop. The study was conducted over two consecutive seasons using three large (0.48 ha) wildflower plantings paired with control orchard borders in a highly simplified agricultural landscape in California. Honey bee (Apis mellifera L.) and wild bee visitation to wildflower plots were at least an order of magnitude higher than to control plots, but increased honey bee visitation to wildflower plots did not lead to any detectable shifts in honey bee visitation to almond flowers in the neighboring orchard. Wild bees were rarely observed visiting almond flowers irrespective of border treatment, indicating a limited short-term potential for augmenting crop pollination using wild bees in highly simplified agricultural landscapes. Although further studies are warranted on bee visitation and crop yield from spatially independent orchards, this study indicates that growers can support bees with alternative forage in almond orchards without risking competition between the wildflower plantings and the crop. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Widespread applications of citrus cryopreservation

USDA-ARS?s Scientific Manuscript database

Citrus genetic resources can now be successfully cryopreserved, which means that they can be placed into long-term storage at liquid nitrogen temperatures. This cryopreservation technology was specifically developed to address the immediate need to have secure long-term back-up storage for citrus co...

The flavor of citrus fruit

USDA-ARS?s Scientific Manuscript database

Citrus is the largest cultivated fruit tree crop in the world, with total production of more than 100 million tons per year. The genus Citrus consists of different species, including several producing economically important crops, such as oranges, mandarins, grapefruit, pummelo, lemons and limes, c...

Genome wide selection in Citrus breeding.

PubMed

Gois, I B; Borém, A; Cristofani-Yaly, M; de Resende, M D V; Azevedo, C F; Bastianel, M; Novelli, V M; Machado, M A

2016-10-17

Genome wide selection (GWS) is essential for the genetic improvement of perennial species such as Citrus because of its ability to increase gain per unit time and to enable the efficient selection of characteristics with low heritability. This study assessed GWS efficiency in a population of Citrus and compared it with selection based on phenotypic data. A total of 180 individual trees from a cross between Pera sweet orange (Citrus sinensis Osbeck) and Murcott tangor (Citrus sinensis Osbeck x Citrus reticulata Blanco) were evaluated for 10 characteristics related to fruit quality. The hybrids were genotyped using 5287 DArT_seq TM (diversity arrays technology) molecular markers and their effects on phenotypes were predicted using the random regression - best linear unbiased predictor (rr-BLUP) method. The predictive ability, prediction bias, and accuracy of GWS were estimated to verify its effectiveness for phenotype prediction. The proportion of genetic variance explained by the markers was also computed. The heritability of the traits, as determined by markers, was 16-28%. The predictive ability of these markers ranged from 0.53 to 0.64, and the regression coefficients between predicted and observed phenotypes were close to unity. Over 35% of the genetic variance was accounted for by the markers. Accuracy estimates with GWS were lower than those obtained by phenotypic analysis; however, GWS was superior in terms of genetic gain per unit time. Thus, GWS may be useful for Citrus breeding as it can predict phenotypes early and accurately, and reduce the length of the selection cycle. This study demonstrates the feasibility of genomic selection in Citrus.

Rock fragment cover controls the sediment detachment in citrus plantations

NASA Astrophysics Data System (ADS)

Cerdà, Artemi; Keesstra, Saskia; Hamidreza Sadeghi, Seyed; Brevik, Eric; Giménez Morera, Antonio; Novara, Agata; Masto, Reginald E.; Jordán, Antonio; Wang, Juan

2016-04-01

Citrus orchards are seen as a source of sediments and water due to the lack of vegetation cover, the widespread use of herbicides, the compaction due to the use of heavy machinery, the lack of organic amendments and the removal of the pruned branches (Cerdà and Jurgensen, 2008; Cerdà et al., 2009; Cerdà and Jurgensen, 2011; Li et al, 2011). This is not unusual in agriculture, where high soil erosion losses are found in the orchards (Dai et al., 2015; Erkossa et al., 2015; Ochoa-Cueva et al., 2015). Therefore, there is a need to reduce the sediment delivery, and to achieve a sustainable situation with lower and renewable soil erosion rates (Cerdà et al., 2015; Nanko et al., 2015; Mwango et al., 2016). Vegetation cover is the most efficient strategy to control soil and water losses at different scales (Cerdà, 1999; Keesstra, 2007; Zhao et al., 2014), but farmers in the Mediterranean Regions prefer bare soils as this reduces the amount of water used by the plants, and also because of aesthetic concerns, as bare soils are perceived as tidy and therefore seen by farmers as the way their orchards should look. So therefore, there is a need to find an efficient strategy that reduces soil losses and will be accepted by the farmers also. One potential option for this may be to use rock fragments (stones) as a mulch to reduce the soil losses. Other researchers already found rock fragments to be an effective tool to reduce erosion (Poesen et al., 1994; Poesen and Lavee, 1994; Cerdà, 2001; Jomaa et al., 2012; Martínez Zavala and Jordán, 2008; Jordán and Martínez Zavala, 2008; Jordán et al., 2009; Zavala et al., 2010). Furthermore, rock fragments can improve soil quality and contribute to the restoration of ecosystems (Jiménez et al., 2015). However, most previous research on soil erosion and rock fragment cover was done under laboratory conditions or in forest soils. Meanwhile, little is known about the role of rock fragments in agriculture land under field

Horsfall-Barratt recalibration and replicated severity estimates of citrus canker

USDA-ARS?s Scientific Manuscript database

Citrus canker is a serious disease of citrus in tropical and subtropical citrus growing regions. Accurate and precise assessment of citrus canker and other plant pathogens is needed to obtain good quality data. Citrus canker assessment data were used to ascertain some of the mechanics of the Horsfal...

Phenology of Asian citrus psyllid (Hemiptera: Liviidae) and associated parasitoids on two species of Citrus, kinnow mandarin and sweet orange, in Punjab Pakistan.

PubMed

Khan, Shouket Zaman; Arif, Muhammad Jalal; Hoddle, Christina D; Hoddle, Mark S

2014-10-01

The population phenology of Asian citrus psyllid, Diaphorina citri Kuwayama, was monitored weekly for 110 wk on two species of Citrus, kinnow mandarin and sweet orange, at two different research sites in Faisalabad, Punjab Pakistan. Citrus flush growth patterns were monitored and natural enemy surveys were conducted weekly. Flush patterns were similar for kinnow and sweet orange. However, flush on sweet orange was consistently more heavily infested with Asian citrus psyllid than kinnow flush; densities of Asian citrus psyllid eggs, nymphs, and adults were higher on sweet orange when compared with kinnow. When measured in terms of mean cumulative insect or Asian citrus psyllid days, eggs, nymphs, and adults were significantly higher on sweet orange than kinnow. Two parasitoids were recorded attacking Asian citrus psyllid nymphs, Tamarixia radiata (Waterston) and Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal). The dominant parasitoid species attacking Asian citrus psyllid nymphs on kinnow and sweet orange was T. radiata, with parasitism averaging 26%. D. aligarhensis parasitism averaged 17%. Generalist predators such as coccinellids and chrysopids were collected infrequently and were likely not important natural enemies at these study sites. Immature spiders, in particular, salticids and yellow sac spiders, were common and may be important predators of all Asian citrus psyllid life stages. Low year round Asian citrus psyllid densities on kinnow and possibly high summer temperatures, may, in part, contribute to the success of this cultivar in Punjab where Candidatus Liberibacter asiaticus, the putative causative agent of huanglongbing, a debilitating citrus disease, is widespread and vectored by Asian citrus psyllid.

Arsenic Recovery by Stinging Nettle From Lead-Arsenate Contaminated Orchard Soils

USDA-ARS?s Scientific Manuscript database

Soil contamination with arsenic (As) is common in orchards with a history of lead-arsenate pesticide application. This problem is prevalent in the U.S. Northeast where lead-arsenate foliar sprays were used to control codling moth (Cydia pomonella) in apple orchards. Arsenic is not easily biodegrad...

Integrated Management of Citrus Canker

USDA-ARS?s Scientific Manuscript database

Fruit losses due to citrus canker, caused by Xanthomonas citri subsp. citri (Xcc), vary each crop season depending on citrus variety, tree age, flushing condition, leafminer control, and coincidence of weather events with occurrence of susceptible fruit and foliage. In 2012, crop losses in Hamlin f...

H NMR analyses of Citrus macrophylla subjected to Asian citrus psyllid (Diaphorina citri Kuwayama) feeding

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid (ACP) is a phloem feeding insect that can host and transmit the bacterium Candidatus Liberibacter asiaticus (CLas), which is the putative causative agent of the economically important citrus disease, Huanglongbing (HLB). ACP are widespread in Florida, and are spreading in Ca...

Microbial communities and soil fertility in flood irrigated orchards under different management systems in eastern spain

NASA Astrophysics Data System (ADS)

Morugán-Coronado, Alicia; García-Orenes, Fuensanta; Caravaca, Fuensanta; Roldán, Antonio

2016-04-01

Unsuitable land management such as the excessive use of herbicides can lead to a loss of soil fertility and a drastic reduction in the abundance of microbial populations and their functions related to nutrient cycling. Microbial communities are the most sensitive and rapid indicators of perturbations in agroecosystems. A field experiment was performed in an orange-trees orchard (Citrus sinensis) to assess the long-term effect of three different management systems on the soil microbial community biomass, structure and composition (phospholipid fatty acids (PLFAs) total, pattern, and abundance). The three agricultural systems assayed were established 30 years ago: herbicides (Glyphosate (N-(phosphonomethyl)glycine) with inorganic fertilizers (H), intensive ploughing and inorganic fertilizers (NPK 15%) (P) and organic farming (chipped pruned branches and weeds, manure from sheep and goats) (O). Nine soil samples were taken from each system. The results showed that the management practices including herbicides and intensive ploughing had similar results on soil microbial properties, while organic fertilization significantly increased microbial biomass, shifted the structure and composition of the soil microbial community, and stimulated microbial activity, when compared to inorganic fertilization systems; thus, enhancing the sustainability of this agroecosystem under semiarid conditions.

RNAi-based strategy for Asian citrus psyllid (Diaphorina citri) Control: A method to reduce the spread of citrus greening disease

USDA-ARS?s Scientific Manuscript database

Citrus greening disease is a serious bacterial disease of citrus worldwide and is vectored by the Asian citrus pysllid (Diaphorina Citri). The only effective control strategy includes vigorous control of the psyllid, primarily through heavy reliance on pesticides. As a more sustainable and environm...

Development of SSR markers from Citrus clementina (Rutaceae) BAC end sequences and interspecific transferability in Citrus.

PubMed

Ollitrault, Frédérique; Terol, Javier; Pina, Jose Antonio; Navarro, Luis; Talon, Manuel; Ollitrault, Patrick

2010-11-01

Microsatellite primers were developed from bacterial artificial chromosome (BAC) end sequences of Citrus clementina and their transferability and polymorphism tested in the genus Citrus for future anchorage of physical and genetic maps and comparative interspecific genetic mapping. • Using PAGE and DNA silver staining, 79 primer pairs were selected for their transferability and polymorphism among 526 microsatellites mined in BES. A preliminary diversity study in Citrus was conducted with 18 of them, in C. reticulata, C. maxima, C. medica, C. sinensis, C. aurantium, C. paradisi, C. lemon, C. aurantifolia, and some papedas (wild citrus), using a capillary electrophoresis fragment analyzer. Intra- and interspecific polymorphism was observed, and heterozygous markers were identified for the different genotypes to be used for genetic mapping. • These results indicate the utility of the developed primers for comparative mapping studies and the integration of physical and genetic maps.

Cost-benefit trade-offs of bird activity in apple orchards.

PubMed

Peisley, Rebecca K; Saunders, Manu E; Luck, Gary W

2016-01-01

Birds active in apple orchards in south-eastern Australia can contribute positively (e.g., control crop pests) or negatively (e.g., crop damage) to crop yields. Our study is the first to identify net outcomes of these activities, using six apple orchards, varying in management intensity, in south-eastern Australia as a study system. We also conducted a predation experiment using real and artificial codling moth (Cydia pomonella) larvae (a major pest in apple crops). We found that: (1) excluding birds from branches of apple trees resulted in an average of 12.8% more apples damaged by insects; (2) bird damage to apples was low (1.9% of apples); and (3) when trading off the potential benefits (biological control) with costs (bird damage to apples), birds provided an overall net benefit to orchard growers. We found that predation of real codling moth larvae was higher than for plasticine larvae, suggesting that plasticine prey models are not useful for inferring actual predation levels. Our study shows how complex ecological interactions between birds and invertebrates affect crop yield in apples, and provides practical strategies for improving the sustainability of orchard systems.

Cost-benefit trade-offs of bird activity in apple orchards

PubMed Central

Saunders, Manu E.; Luck, Gary W.

2016-01-01

Birds active in apple orchards in south–eastern Australia can contribute positively (e.g., control crop pests) or negatively (e.g., crop damage) to crop yields. Our study is the first to identify net outcomes of these activities, using six apple orchards, varying in management intensity, in south–eastern Australia as a study system. We also conducted a predation experiment using real and artificial codling moth (Cydia pomonella) larvae (a major pest in apple crops). We found that: (1) excluding birds from branches of apple trees resulted in an average of 12.8% more apples damaged by insects; (2) bird damage to apples was low (1.9% of apples); and (3) when trading off the potential benefits (biological control) with costs (bird damage to apples), birds provided an overall net benefit to orchard growers. We found that predation of real codling moth larvae was higher than for plasticine larvae, suggesting that plasticine prey models are not useful for inferring actual predation levels. Our study shows how complex ecological interactions between birds and invertebrates affect crop yield in apples, and provides practical strategies for improving the sustainability of orchard systems. PMID:27413639

[Diversity of Hemiptera Auchenorrhyncha in citrus, coffee and a fragment of native forest of the state of São Paulo].

PubMed

Giustolin, Teresinha A; Lopes, João R S; Querino, Ranyse B; Cavichioli, Rodney R; Zanol, Kety; Azevedo Filho, Wilson S; Mendes, Miguel A

2009-01-01

The population of Hemiptera Auchenorrhyncha was studied in sweet citrus groves (Citrus sinensis), coffee plantations (Coffea arabica) and a semi-deciduous seasonal forest with shrub physiognomy in Bebedouro, SP, to evaluate the influence of the natural ecosystem on the species composition of the agroecosystems. Monitoring was carried out by using yellow stick cards, which were replaced every 15 days and all Auchenorrhyncha collected were counted and identified. Seven families, 11 subfamilies and 98 species were collected, with Cicadellidae being the most abundant. The native forest presented larger wealth, diversity and equitability of Auchenorrhyncha species, demonstrating to be more stable than the other habitats. The high values of similarities obtained between the agroecosystems and the forest demonstrated that great part of Auchenorrhyncha species occurring in the agricultural habitats was also occurring at the forest, indicating that the last may serve as reservoir of species. The abundance of the taxonomic groups of Auchenorrhyncha collected varied with the evaluated habitats, with Proconiini being the most abundant in the coffee plantation next to the forest, Athysanini, Scaphytopiini, Neocoelidiinae and Coelidiinae in the orange orchard and coffee plantation distant from the forest; Cicadellinae and Agalliinae were not related to any of the habitats. The presence of vector insects and possible vectors of plant diseases in the appraised habitats indicate the need of the implementation of strategies for landscape management.

Effects of High Toxic Boron Concentration on Protein Profiles in Roots of Two Citrus Species Differing in Boron-Tolerance Revealed by a 2-DE Based MS Approach

PubMed Central

Sang, Wen; Huang, Zeng-Rong; Yang, Lin-Tong; Guo, Peng; Ye, Xin; Chen, Li-Song

2017-01-01

Citrus are sensitive to boron (B)-toxicity. In China, B-toxicity occurs in some citrus orchards. So far, limited data are available on B-toxicity-responsive proteins in higher plants. Thirteen-week-old seedlings of “Sour pummelo” (Citrus grandis) and “Xuegan” (Citrus sinensis) was fertilized every other day until dripping with nutrient solution containing 10 μM (control) or 400 μM (B-toxicity) H3BO3 for 15 weeks. The typical B-toxic symptom only occurred in 400 μM B-treated C. grandis leaves, and that B-toxicity decreased root dry weight more in C. grandis seedlings than in C. sinensis ones, demonstrating that C. sinensis was more tolerant to B-toxicity than C. grandis. Using a 2-dimensional electrophoresis (2-DE) based MS approach, we identified 27 up- and four down-accumulated, and 28 up- and 13 down-accumulated proteins in B-toxic C. sinensis and C. grandis roots, respectively. Most of these proteins were isolated only from B-toxic C. sinensis or C. grandis roots, only nine B-toxicity-responsive proteins were shared by the two citrus species. Great differences existed in B-toxicity-induced alterations of protein profiles between C. sinensis and C. grandis roots. More proteins related to detoxification were up-accumulated in B-toxic C. grandis roots than in B-toxic C. sinensis roots to meet the increased requirement for the detoxification of the more reactive oxygen species and other toxic compounds such as aldehydes in the former. For the first time, we demonstrated that the active methyl cycle was induced and repressed in B-toxic C. sinensis and C. grandis roots, respectively, and that C. sinensis roots had a better capacity to keep cell wall and cytoskeleton integrity than C. grandis roots in response to B-toxicity, which might be responsible for the higher B-tolerance of C. sinensis. In addition, proteins involved in nucleic acid metabolism, biological regulation and signal transduction might play a role in the higher B-tolerance of C. sinensis

Enhanced Acquisition Rates of 'Candidatus Liberibacter asiaticus' by the Asian Citrus Psyllid (Hemiptera: Liviidae) in the Presence of Vegetative Flush Growth in Citrus.

PubMed

Sétamou, Mamoudou; Alabi, Olufemi J; Kunta, Madhurababu; Jifon, John L; da Graça, John V

2016-10-01

The Asian citrus psyllid preferentially feeds and exclusively reproduces on young, newly emerged flush shoots of citrus. Asian citrus psyllid nymphs feed and complete their life stages on these flush shoots. Recent studies conducted under greenhouse conditions have shown that the transmission rates of 'Candidatus Liberibacter asiaticus' (CLas), the putative causal agent of huanglongbing disease of citrus, are enhanced when flush shoots are present. However, it is unclear if CLas acquisition by migrant adult Asian citrus psyllids is similarly enhanced. To address this knowledge gap, cohorts of Asian citrus psyllid adults were allowed 1-wk acquisition access period (AAP) on flushing and nonflushing shoots of qPCR-tested symptomatic (CLas+) and asymptomatic (CLas-) 10-yr-old sweet orange trees under field conditions. After the AAP, they were tested for CLas by qPCR. Progeny Asian citrus psyllid adults that emerged 4 wk post-AAP were similarly retrieved and tested. Eighty percent of flushing and 30% of nonflushing CLas+ trees produced infective Asian citrus psyllid adults, indicating that flush shoots have greater potential to be inoculum sources for CLas acquisition. Concomitantly, 21.1% and 6.0% infective adults were retrieved, respectively, from flushing and nonflushing CLas+ trees, indicating that Asian citrus psyllid adults acquire CLas more efficiently from flush shoots relative to mature shoots. In addition, 12.1% of infective Asian citrus psyllid adult progeny were obtained from 70% of flushing CLas+ trees. Significantly lower mean Ct values were also obtained from infective adults retrieved from flushing relative to nonflushing trees. The results underscore the role of flush shoots in CLas acquisition and the need to protect citrus trees from Asian citrus psyllid infestations during flush cycles. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email

Biological Indexing of Graft Transmissible Diseases of Citrus

USDA-ARS?s Scientific Manuscript database

Biological indexing for the detection of graft transmissible diseases of citrus is essential for maintaining a citrus certification program. Many of the graft transmissible diseases of citrus are harbored as latent infections in the scions, but when propagated on a susceptible rootstock that allow...

Sclerenchymatous ring as a barrier to phloem feeding by Asian citrus psyllid: Evidence from electrical penetration graph and visualization of stylet pathways

PubMed Central

George, Justin; Ammar, El-Desouky; Hall, David G.

2017-01-01

Asian citrus psyllid (Diaphorina citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Sustained phloem ingestion by D. citri on CLas infected plants is required for pathogen acquisition and transmission. Recent studies have shown a fibrous ring of thick-walled sclerenchyma around the phloem in mature, fully expanded citrus leaves that is more prominent on the abaxial compared with the adaxial side. The composition and thickness of this fibrous ring may have an important role in selection of feeding sites by D. citri based on leaf age and leaf surface, which in turn can affect pathogen acquisition and transmission. We measured feeding behavior using electrical penetration graph (EPG) recordings of individual D. citri adults placed on abaxial or adaxial surfaces of young or mature Valencia orange leaves to study the role of the sclerenchymatous ring in modifying D. citri feeding behavior. Feeding sites on the same leaf tissues were then sectioned and examined by epifluorescence microscopy. The duration of phloem ingestion (E2 waveform) by psyllids was significantly reduced on mature compared with young leaves, and on abaxial compared with adaxial leaf surfaces. The longest duration of phloem ingestion was observed from psyllids placed on the adaxial side of young leaves that had the least developed sclerenchyma. Bouts of phloem salivation (E1 waveform), however, were significantly longer on mature leaves compared with young leaves. D. citri adults made consecutive phloem feeding attempts (bouts) on the abaxial side of mature leaves and those bouts resulted in unsuccessful or shorter periods of phloem ingestion. Adults also made more frequent and longer bouts of xylem ingestion on mature leaves compared with adult psyllids placed on young leaves. Epifluorescence microscopy showed that the fibrous ring in young

Sclerenchymatous ring as a barrier to phloem feeding by Asian citrus psyllid: Evidence from electrical penetration graph and visualization of stylet pathways.

PubMed

George, Justin; Ammar, El-Desouky; Hall, David G; Lapointe, Stephen L

2017-01-01

Asian citrus psyllid (Diaphorina citri) feeding behaviors play a significant role in the transmission of the phloem-limited Candidatus Liberibacter asiaticus (CLas) bacterium that causes the economically devastating citrus greening disease. Sustained phloem ingestion by D. citri on CLas infected plants is required for pathogen acquisition and transmission. Recent studies have shown a fibrous ring of thick-walled sclerenchyma around the phloem in mature, fully expanded citrus leaves that is more prominent on the abaxial compared with the adaxial side. The composition and thickness of this fibrous ring may have an important role in selection of feeding sites by D. citri based on leaf age and leaf surface, which in turn can affect pathogen acquisition and transmission. We measured feeding behavior using electrical penetration graph (EPG) recordings of individual D. citri adults placed on abaxial or adaxial surfaces of young or mature Valencia orange leaves to study the role of the sclerenchymatous ring in modifying D. citri feeding behavior. Feeding sites on the same leaf tissues were then sectioned and examined by epifluorescence microscopy. The duration of phloem ingestion (E2 waveform) by psyllids was significantly reduced on mature compared with young leaves, and on abaxial compared with adaxial leaf surfaces. The longest duration of phloem ingestion was observed from psyllids placed on the adaxial side of young leaves that had the least developed sclerenchyma. Bouts of phloem salivation (E1 waveform), however, were significantly longer on mature leaves compared with young leaves. D. citri adults made consecutive phloem feeding attempts (bouts) on the abaxial side of mature leaves and those bouts resulted in unsuccessful or shorter periods of phloem ingestion. Adults also made more frequent and longer bouts of xylem ingestion on mature leaves compared with adult psyllids placed on young leaves. Epifluorescence microscopy showed that the fibrous ring in young

Site Plan & Site Section of Citrus Landscape (Showing Relationship ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Site Plan & Site Section of Citrus Landscape (Showing Relationship of Victoria Avenue to Citrus Groves) - Arlington Heights Citrus Landscape, Southwestern portion of city of Riverside, Riverside, Riverside County, CA

[Effects of fertilizing regime and planting age on soil calcium decline in Luochuan apple orchards].

PubMed

Li, Peng; Li, Chun Yue; Wang, Yi Quan; Jiao, Cai Qiang

2017-05-18

This study was conducted to assess the effects of fertilizing regime and orchard planting age on soil calcium contents and stocks in the apple orchards on the Loess Plateau. The apple orchards in Luochuan County, one of the best regions for apple plantation in the world, were selec-ted in this study. The contents of calcium carbonate,water-soluble calcium and exchangeable cal-cium at 0-100 cm soil layer under different fertilizing regimes and various planting ages were mea-sured, their stocks were calculated and their variation features were analyzed. The results showed that soil in the apple orchards in the study region was characterized by the decline in calcium contents. The decline was more serious in apple orchards with long-term application of chemical fertili-zer than in those with combined application of chemical fertilizer and farmyard manure. The average contents of calcium carbonate, water-soluble calcium and exchangeable calcium at 0-100 cm soil layer in apple orchards with long-term application of chemical fertilizer decreased by 38.8%, 25.4% and 5.6% respectively than those in the apple orchards with long-term application of both chemical fertilizer and farmyard manure. The stocks of calcium carbonate, water-soluble calcium and exchangeable calcium decreased by 36.4%, 26.0% and 4.3%, respectively. The decline of soil cal-cium was aggravated with the increase of orchard planting age. The contents of calcium carbonate, water-soluble calcium and exchangeable calcium at 0-100 cm soil layer in orchards of more than 25 years of planting age decreased by 48.8%, 69.4% and 39.5% respectively, compared with orchards of less than 10 years of planting age, and the stocks decreased by 40.8%, 64.1% and 33.0%, respectively. These results indicated that either long-term application of chemical fertilizer or long-term plantation of apple trees obviously depleted soil calcium carbonate, water-soluble calcium and exchangeable calcium. Therefore, it was recommended that

ACP and Citrus: Plant Responses to Psyllid Feeding

USDA-ARS?s Scientific Manuscript database

Progress is reported on the Citrus Research Board funded project: 5300-150 Biomarkers for the detection of Liberibacter infection in citrus through H-NMR-based metabolomics. Proton nuclear magnetic resonance (H-NMR) was used to determine the effects of Asian citrus psyllid (ACP) feeding on leaf meta...

A comparison of plant species for rearing Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

Five plant genotypes were compared with respect to Asian citrus psyllid (ACP) reproduction potential: Bergera koenigii, Citrus aurantiifolia, C. macrophylla, C. taiwanica and Murraya paniculata. Asian citrus psyllid reproduction is dependent on young flush and thus Asian citrus psyllid production po...

Citrus tristeza virus-based RNAi in citrus plants induces gene silencing in Diaphorina citri, a phloem-sap sucking insect vector of citrus greening disease (Huanglongbing).

PubMed

Hajeri, Subhas; Killiny, Nabil; El-Mohtar, Choaa; Dawson, William O; Gowda, Siddarame

2014-04-20

A transient expression vector based on Citrus tristeza virus (CTV) is unusually stable. Because of its stability it is being considered for use in the field to control Huanglongbing (HLB), which is caused by Candidatus Liberibacter asiaticus (CLas) and vectored by Asian citrus psyllid, Diaphorina citri. In the absence of effective control strategies for CLas, emphasis has been on control of D. citri. Coincident cohabitation in phloem tissue by CLas, D. citri and CTV was exploited to develop a novel method to mitigate HLB through RNA interference (RNAi). Since CTV has three RNA silencing suppressors, it was not known if CTV-based vector could induce RNAi in citrus. Yet, expression of sequences targeting citrus phytoene desaturase gene by CTV-RNAi resulted in photo-bleaching phenotype. CTV-RNAi vector, engineered with truncated abnormal wing disc (Awd) gene of D. citri, induced altered Awd expression when silencing triggers ingested by feeding D. citri nymphs. Decreased Awd in nymphs resulted in malformed-wing phenotype in adults and increased adult mortality. This impaired ability of D. citri to fly would potentially limit the successful vectoring of CLas bacteria between citrus trees in the grove. CTV-RNAi vector would be relevant for fast-track screening of candidate sequences for RNAi-mediated pest control. Copyright © 2014. Published by Elsevier B.V.

Analysis of full-length sequences of two Citrus yellow mosaic badnavirus isolates infecting Citrus jambhiri (Rough Lemon) and Citrus sinensis L. Osbeck (Sweet Orange) from a nursery in India.

PubMed

Anthony Johnson, A M; Borah, B K; Sai Gopal, D V R; Dasgupta, I

2012-12-01

Citrus yellow mosaic badna virus (CMBV), a member of the Family Caulimoviridae, Genus Badnavirus is the causative agent of mosaic disease among Citrus species in southern India. Despite its reported prevalence in several citrus species, complete information on clear functional genomics or functional information of full-length genomes from all the CMBV isolates infecting citrus species are not available in publicly accessible databases. CMBV isolates from Rough Lemon and Sweet Orange collected from a nursery were cloned and sequenced. The analysis revealed high sequence homology of the two CMBV isolates with previously reported CMBV sequences implying that they represent new variants. Based on computational analysis of the predicted secondary structures, the possible functions of some CMBV proteins have been analyzed.

A comparison of the nesting success of mourning doves and American robins in conventionally managed and organic orchards

USGS Publications Warehouse

Fluetsch, K.M.

1992-01-01

A comparative study was undertaken to document more closely the effects of operational pesticide use on non-target avian species. Mourning Dove (Zenaida macroura) and American Robin (Turdus migratorius) nesting activity was monitored in three organic and three conventional orchards during two breeding seasons. Surveys were conducted to characterize the avian community within orchards under both management practices. Organophosphorus (OP) and carbamate pesticides, known to be extremely toxic to birds, were repeatedly sprayed during the peaks in dove and robin breeding activity. Spray card tests revealed that OP pesticides were deposited on 85.5% of the nests tested during routine spray operations. The threat of direct pesticide exposure to eggs, nestlings, and adult birds was considerable. Nest daily survival rates (DSRs) for both doves and robins, were significantly higher in the organic orchards than in the conventional orchards in 1991 and years combined (P < 0.05). Species diversity was significantly greater in the organic orchards (H = 2.43) than in the conventional orchards (H = 1.79). Results suggest that repeated applications of pesticides, within the conventional orchards, directly or indirectly, affected the reproductive success of doves and robins, as well as influenced species diversity within the treated orchards. Organic orchards appear to provide more favorable nesting and foraging habitat for birds than conventional orchards.

Chemical control of the Asian citrus psyllid and of huanglongbing disease in citrus.

PubMed

Boina, Dhana Raj; Bloomquist, Jeffrey R

2015-06-01

By 2014, huanglongbing (HLB), the most destructive disease of citrus, and its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama), became established in all major citrus-growing regions of the world, including the United States, with the exception of California. At present, application of insecticides is the most widely followed option for reducing ACP populations, while application of antibiotics for suppressing HLB disease/symptoms is being practiced in some citrus-growing regions. Application of insecticides during the dormant winter season, along with cultivation of HLB-free seedlings and early detection and removal of symptomatic and asymptomatic trees, has been very effective in managing ACP. Area-wide management of ACP by application of insecticides at low volume in large areas of citrus cultivation has been shown to be effective in managing HLB and reducing management costs. As insecticide resistance is a major problem in sustainable management of ACP, rotation/alternation of insecticides with different chemistries and modes of action needs to be followed. Besides control of the insect vector, use of antibiotics has temporarily suppressed the symptoms of HLB in diseased trees. Recent efforts to discover and screen existing as well as new compounds for their antibiotic and antimicrobial activities have identified some promising molecules for HLB control. There is an urgent need to find a sustainable solution to the HLB menace through chemical control of ACP populations and within HLB-infected trees through the judicious use of labeled insecticides (existing and novel chemistries) and antibiotics in area-wide management programs with due consideration to the insecticide resistance problem. © 2014 Society of Chemical Industry.

Real-Time Variable Rate Spraying in Orchards and Vineyards: A Review

NASA Astrophysics Data System (ADS)

Wandkar, Sachin Vilas; Bhatt, Yogesh Chandra; Jain, H. K.; Nalawade, Sachin M.; Pawar, Shashikant G.

2018-06-01

Effective and efficient use of pesticides in the orchards is of concern since many years. With the conventional constant rate sprayers, equal dose of pesticide is applied to each tree. Since, there is great variation in size and shape of each tree in the orchard, trees gets either oversprayed or undersprayed. Real-time variable rate spraying technology offers pesticide application in accordance with tree size. With the help of suitable sensors, tree characteristics such as canopy volume, foliage density, etc. can be acquired and with the micro-processing unit coupled with proper algorithm, flow of electronic proportional valves can be controlled thus, controlling the flow rate of nozzles according to tree characteristics. Also, sensors can help in the detection of spaces in-between trees which allows to control the spray in spaces. Variable rate spraying helps in achieving precision in spraying operation especially inside orchards. This paper reviews the real-time variable rate spraying technology and efforts made by the various researchers for real-time variable application in the orchards and vineyards.

Real-Time Variable Rate Spraying in Orchards and Vineyards: A Review

NASA Astrophysics Data System (ADS)

Wandkar, Sachin Vilas; Bhatt, Yogesh Chandra; Jain, H. K.; Nalawade, Sachin M.; Pawar, Shashikant G.

2018-02-01

Effective and efficient use of pesticides in the orchards is of concern since many years. With the conventional constant rate sprayers, equal dose of pesticide is applied to each tree. Since, there is great variation in size and shape of each tree in the orchard, trees gets either oversprayed or undersprayed. Real-time variable rate spraying technology offers pesticide application in accordance with tree size. With the help of suitable sensors, tree characteristics such as canopy volume, foliage density, etc. can be acquired and with the micro-processing unit coupled with proper algorithm, flow of electronic proportional valves can be controlled thus, controlling the flow rate of nozzles according to tree characteristics. Also, sensors can help in the detection of spaces in-between trees which allows to control the spray in spaces. Variable rate spraying helps in achieving precision in spraying operation especially inside orchards. This paper reviews the real-time variable rate spraying technology and efforts made by the various researchers for real-time variable application in the orchards and vineyards.

Determination of polymethoxylated flavones in peels of selected Jamaican and Mexican citrus (Citrus spp.) cultivars by high-performance liquid chromatography.

PubMed

Green, Curtis O; Wheatley, Andrew O; Osagie, Anthony U; St A Morrison, Errol Y; Asemota, Helen N

2007-01-01

The concentrations of the polymethoxylated flavones (PMFs) in peels of selected citrus cultivars grown in Jamaica and Mexico were determined. The PMFs were extracted from sun-dried citrus peels with reagent-grade methanol. Analyses were carried out by reverse-phase HPLC and UV detection. The column used was a C(18) 5 microm (150 x 4.6 mm) Discovery column. Elution was in the gradient mode, using a ternary mobile phase. The results showed that all the citrus cultivars used contained at least three of the six major PMFs quantified. Ortanique peel contained the highest quantity of PMFs (34,393 +/- 272 ppm), followed by tangerine (28,389 +/- 343 ppm) and Mexican sweet orange (sample 1; 21,627 +/- 494 ppm). The major PMFs, i.e. sinensetin, nobiletin, tangeretin, heptamethoxyflavone, tetramethylscutellarein and hexamethyl-o-quercetagetin, present in the peels of 20 citrus cultivars, was quantified. The results were compared with those of Florida citrus peels. A large amount of citrus peels and byproducts are produced in the Caribbean which could provide a cheap and convenient source of PMFs. Copyright 2006 John Wiley & Sons, Ltd.

Orchard Management: Horticultural Practices for Peace Corps Volunteers. Appropriate Technologies for Development. Reprint R-31.

ERIC Educational Resources Information Center

Development and Resources Corp.

This manual is intended for use by Peace Corps volunteers as a resource for gaining an understanding and knowledge of basic horticultural principles and practices of orchard management. Addressed in the individual units of instructional text are orchard soils; botany of horticultural plants; insect and disease control in orchards; pome, stone,…

Comparison of evapotranspiration rates for flatwoods and ridge citrus

USGS Publications Warehouse

Jia, X.; Swancar, A.; Jacobs, J.M.; Dukes, M.D.; Morgan, K.

2007-01-01

Florida citrus groves are typically grown in two regions of the state: flatwoods and ridge. The southern flatwoods citrus area has poorly drained fine textured sands with low organic matter in the shallow root zone. Ridge citrus is located in the northern ridge citrus zone and has fine to coarse textured sands with low water-holding capacity. Two commercial citrus groves, selected from each region, were studied from 15 July 2004 to 14 July 2005. The flatwoods citrus (FC) grove had a grass cover and used drainage ditches to remove excess water from the root zone. The ridge citrus (RC) grove had a bare soil surface with weeds periodically eliminated by tillage. Citrus crop evapotranspiration (ETc) rates at the two citrus groves were measured by the eddy correlation method, and components in the energy balance were also examined and compared. The study period had higher than average rainfall, and as a result, the two locations had similar annual ETc rates (1069 and 1044 mm for RC and FC, respectively). The ETc rates were 59% (RC) and 47% (FC) of the rainfall amounts during the study period. The annual reference crop evapotranspiration (ETo) rates were 1180 mm for RC and 1419 mm for FC, estimated using the standardized reference evapotranspiration equation. The citrus crop coefficients (Kc, ratio of ETc to ET o) were different between the two locations because of differences in latitude, ground cover, and rainfall amounts. The Kc values ranged from 0.70 between December and March to 1.05 between July and November for RC, and from 0.65 between November and May to 0.85 between June and October for FC. The results are consistent with other Kc values reported from field studies on citrus in both Florida and elsewhere using these and alternate methods.

Changes in Anthocyanin Production during Domestication of Citrus1[OPEN

PubMed Central

Garcia-Lor, Andrés; Licciardello, Concetta; Las Casas, Giuseppina; Ramadugu, Chandrika; Krueger, Robert; Fanciullino, Anne-Laure; Froelicher, Yann

2017-01-01

Mandarin (Citrus reticulata), citron (Citrus medica), and pummelo (Citrus maxima) are important species of the genus Citrus and parents of the interspecific hybrids that constitute the most familiar commercial varieties of Citrus: sweet orange, sour orange, clementine, lemon, lime, and grapefruit. Citron produces anthocyanins in its young leaves and flowers, as do species in genera closely related to Citrus, but mandarins do not, and pummelo varieties that produce anthocyanins have not been reported. We investigated the activity of the Ruby gene, which encodes a MYB transcription factor controlling anthocyanin biosynthesis, in different accessions of a range of Citrus species and in domesticated cultivars. A white mutant of lemon lacks functional alleles of Ruby, demonstrating that Ruby plays an essential role in anthocyanin production in Citrus. Almost all the natural variation in pigmentation by anthocyanins in Citrus species can be explained by differences in activity of the Ruby gene, caused by point mutations and deletions and insertions of transposable elements. Comparison of the allelic constitution of Ruby in different species and cultivars also helps to clarify many of the taxonomic relationships in different species of Citrus, confirms the derivation of commercial varieties during domestication, elucidates the relationships within the subgenus Papeda, and allows a new genetic classification of mandarins. PMID:28196843

Gap probability - Measurements and models of a pecan orchard

NASA Technical Reports Server (NTRS)

Strahler, Alan H.; Li, Xiaowen; Moody, Aaron; Liu, YI

1992-01-01

Measurements and models are compared for gap probability in a pecan orchard. Measurements are based on panoramic photographs of 50* by 135 view angle made under the canopy looking upwards at regular positions along transects between orchard trees. The gap probability model is driven by geometric parameters at two levels-crown and leaf. Crown level parameters include the shape of the crown envelope and spacing of crowns; leaf level parameters include leaf size and shape, leaf area index, and leaf angle, all as functions of canopy position.

Field validation of a system for autodissemination of an entomopathogenic fungus, Isaria fumosorosea, to control the Asian citrus psyllid on residential citrus

USDA-ARS?s Scientific Manuscript database

The citrus industries of California and Texas share a pressing problem with the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) and huanglongbing (HLB) spreading in residential citrus near commercial groves. Insecticidal treatment of residential trees for the psyllid is problem...

Local Plant Diversity Across Multiple Habitats Supports a Diverse Wild Bee Community in Pennsylvania Apple Orchards.

PubMed

Kammerer, Melanie A; Biddinger, David J; Rajotte, Edwin G; Mortensen, David A

2016-02-01

Wild pollinators supply essential, historically undervalued pollination services to crops and other flowering plant communities with great potential to ensure agricultural production against the loss of heavily relied upon managed pollinators. Local plant communities provision wild bees with crucial floral and nesting resources, but the distribution of floristic diversity among habitat types in North American agricultural landscapes and its effect on pollinators are diverse and poorly understood, especially in orchard systems. We documented floristic diversity in typical mid-Atlantic commercial apple (Malus domestica Borkh.) orchards including the forest and orchard-forest edge ("edge") habitats surrounding orchards in a heterogeneous landscape in south-central Pennsylvania, USA. We also assessed the correlation between plant richness and orchard pollinator communities. In this apple production region, edge habitats are the most species rich, supporting 146 out of 202 plant species recorded in our survey. Plant species richness in the orchard and edge habitats were significant predictors of bee species richness and abundance in the orchard, as well as landscape area of the forest and edge habitats. Both the quantity and quality of forest and edges close to orchards play a significant role in provisioning a diverse wild bee community in this agroecosystem. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of yellow sticky traps for monitoring the population of thrips (Thysanoptera) in a mango orchard.

PubMed

Aliakbarpour, Hamaseh; Rawi, Che Salmah Md

2011-08-01

Populations of several thrips species were estimated using yellow sticky traps in an orchard planted with mango, Mangifera indica L. during the dry and wet seasons beginning in late 2008-2009 on Penang Island, Malaysia. To determine the efficacy of using sticky traps to monitor thrips populations, we compared weekly population estimates on yellow sticky traps with thrips population sizes that were determined (using a CO(2) method) directly from mango panicles. Dispersal distance and direction of thrips movement out of the orchard also were studied using yellow sticky traps placed at three distances from the edge of the orchard in four cardinal directions facing into the orchard. The number of thrips associated with the mango panicles was found to be correlated with the number of thrips collected using the sticky trap method. The number of thrips captured by the traps decreased with increasing distance from the mango orchard in all directions. Density of thrips leaving the orchard was related to the surrounding vegetation. Our results demonstrate that sticky traps have the potential to satisfactorily estimate thrips populations in mango orchards and thus they can be effectively employed as a useful tactic for sampling thrips.

Epidemiology of Usher syndrome in Valencia and Spain.

PubMed

Espinós, C; Millán, J M; Beneyto, M; Nájera, C

1998-01-01

To obtain epidemiological data on the prevalence of the different types of Usher syndrome (US) in Spain, since these data were missing; to estimate the proportion of sporadic cases among simplex families, and calculate the prevalence of the Usher syndrome in a homogeneous population from Eastern Spain (3,875,234 inhabitants) that is representative of the Spanish population. Otological, ophthalmological and genetic studies were performed in 89 US patients from 46 families and subjected to statistical and segregation analysis. 41.6% of them suffered US type I, 46.1% type II, and in 12.3% the classification remains unclear. The estimated prevalence for the Province of Valencia was 4.2/100,000. There was a notable excess of male-only affected multiplex sibships in our sample that could be attributable to an X-linked inheritance. The number of families with USI type was similar to that of families with USII type. The estimated prevalence for the Province of Valencia is in agreement with other reports in which the estimate for the prevalence of US ranges from 1.8 to 6.2/100,000.

Monoclonal antibody-based serological methods for detecting Citrus tristeza virus in citrus groves.

PubMed

Liu, Zhen; Chen, Zhe; Hong, Jian; Wang, Xuefeng; Zhou, Changyong; Zhou, Xueping; Wu, Jianxiang

2016-08-01

Citrus tristeza virus (CTV) is one of the most economically important citrus viruses and harms the citrus industry worldwide. To develop reliable and effective serological detection assays of CTV, the major capsid protein (CP) gene of CTV was expressed in Escherichia coli BL21 (DE3) using the expression vector pET-28a and purified through Ni+-NTA affinity chromatography. The recombinant protein was used to immunize BALB/c mice. Four hybridoma cell lines (14B10, 14H11, 20D5, and 20G12) secreting monoclonal antibodies (MAbs) against CTV were obtained through conventional hybridoma technology. The titers of MAb-containing ascitic fluids secreted by the four hybridoma lines ranged from 10(-6) to 10(-7) in indirect enzyme-linked immunosorbent assay (ELISA). Western blots showed that all four MAbs could specifically react with CTV CP. Using the prepared MAbs, dot-ELISA, Tissue print-ELISA, and triple antibody sandwich (TAS)-ELISA were developed to detect CTV in tree nurseries and epidemiological studies. The developed dot-ELISA and TAS-ELISA methods could detect CTV in crude extracts of infected citrus leaves with dilutions of 1:2560 and 1:10, 240 (w/v, g/mL), respectively. Tissue print-ELISA was particularly useful for large-scale field sample detection, mainly owing to its simplicity and lack of sample preparation requirements. The field survey revealed that CTV is prevalent on citrus trees in the Chongqing Municipality, Jiangxi Province, and Zhejiang Province of China. The coincidence rate of serological and RT-PCR test results reached more than 99.5%. The prepared MAbs against CTV and established sensitive and specific serological assays have a significant role in the detection and prevention and control of CTV in our country.

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM).

PubMed

Fletcher, Evelyn; Morgan, Kelly T; Qureshi, Jawwad A; Leiva, Jorge A; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0-45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4-8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and the

Imidacloprid soil movement under micro-sprinkler irrigation and soil-drench applications to control Asian citrus psyllid (ACP) and citrus leafminer (CLM)

PubMed Central

Fletcher, Evelyn; Qureshi, Jawwad A.; Leiva, Jorge A.; Nkedi-Kizza, Peter

2018-01-01

Imidacloprid (IM) is used to control the Asian Citrus Psyllid (ACP) and citrus leafminer (CLM), which are related to the spread of huanglongbing (HLB or citrus greening) and citrus canker diseases, respectively. In Florida citrus, imidacloprid is mainly soil-drenched around the trees for proper root uptake and translocation into plant canopy to impact ACP and CLM. The objective of this study was to determine the effect of imidacloprid rate, and irrigate amount on concentration of imidacloprid in the soil following drench application to citrus trees in three age classes. The plots were established at the Southwest Florida Research and Education Center, Immokalee, using a randomized complete-block design for three age classes of trees: one-year-old trees (B1), three to five-year-old trees (B2), and eight-year-old trees (B3). The treatments were a combination of two rates each of imidacloprid (1D, 2D) and micro-sprinkling irrigation (1I, 2I). Imidacloprid and bromide (Br-) used as tracer were applied simultaneously. Soil moisture and concentrations of imidacloprid and Br were monitored using soil cores from hand held augers. Soil moisture content (θV) did not differ under two irrigation rates at any given observation day or depth, except following heavy rainfall events. Br- was lost from the observation depths (0–45 cm) about two weeks after soil-drench. Contrarily, imidacloprid persisted for a much longer time (4–8 weeks) at all soil depths, regardless of treatment combinations. The higher retardation of imidacloprid was related to the predominantly unsaturated conditions of the soil (which in turn reduced soil hydraulic conductivities by orders of magnitude), the imidacloprid sorption on soil organic matter, and the citrus root uptake. Findings of this study are important for citrus growers coping with the citrus greening and citrus canker diseases because they suggest that imidacloprid soil drenches can still be an effective control measure of ACP and CLM, and

Evaluation of the atoxigenic Aspergillus flavus strain AF36 in pistachio orchards

USDA-ARS?s Scientific Manuscript database

The atoxigenic strain Aspergillus flavus AF36, which has been extensively used as a biocontrol agent in commercial corn and cotton fields to reduce aflatoxin contamination, was applied in research pistachio orchards from 2002 to 2005 and in commercial pistachio orchards from 2008 to 2011. AF36 was a...

Citrus Flavonoids as Regulators of Lipoprotein Metabolism and Atherosclerosis.

PubMed

Mulvihill, Erin E; Burke, Amy C; Huff, Murray W

2016-07-17

Citrus flavonoids are polyphenolic compounds with significant biological properties. This review summarizes recent advances in understanding the ability of citrus flavonoids to modulate lipid metabolism, other metabolic parameters related to the metabolic syndrome, and atherosclerosis. Citrus flavonoids, including naringenin, hesperitin, nobiletin, and tangeretin, have emerged as potential therapeutics for the treatment of metabolic dysregulation. Epidemiological studies reveal an association between the intake of citrus flavonoid-containing foods and a decreased incidence of cardiovascular disease. Studies in cell culture and animal models, as well as a limited number of clinical studies, reveal the lipid-lowering, insulin-sensitizing, antihypertensive, and anti-inflammatory properties of citrus flavonoids. In animal models, supplementation of rodent diets with citrus flavonoids prevents hepatic steatosis, dyslipidemia, and insulin resistance primarily through inhibition of hepatic fatty acid synthesis and increased fatty acid oxidation. Citrus flavonoids blunt the inflammatory response in metabolically important tissues including liver, adipose, kidney, and the aorta. The mechanisms underlying flavonoid-induced metabolic regulation have not been completely established, although several potential targets have been identified. In mouse models, citrus flavonoids show marked suppression of atherogenesis through improved metabolic parameters as well as through direct impact on the vessel wall. Recent studies support a role for citrus flavonoids in the treatment of dyslipidemia, insulin resistance, hepatic steatosis, obesity, and atherosclerosis. Larger human studies examining dose, bioavailability, efficacy, and safety are required to promote the development of these promising therapeutic agents.

Rapid cyling plant breeding in citrus

USDA-ARS?s Scientific Manuscript database

Resistance or tolerance to huanglongbing (HLB) and other important traits have been identified in several citrus types and relatives and associated markers should be identified soon. What is urgently needed in addition is an accelerated strategy for citrus variety breeding. Identification and use of...

Pesticides and brain cancer linked in orchard farmers of Kashmir.

PubMed

Bhat, Abdul Rashid; Wani, Muhammed Afzal; Kirmani, A R; Raina, T H

2010-10-01

The atmosphere of valley of Kashmir is ideal for fresh and dry fruit production. Millions of tons of pesticides, insecticides and fungicides (chemicals like chlorpyriphos, mancozeb, captan, dimethoate, phosalone, etc.) are being used by the orchard farmers to spray the plants, fruits and the leaves every year. The increasing trend in the incidence of primary malignant brain tumors in orchard farmers of Kashmir is alarming. To determine the relationship between the patients of primary malignant brain tumors and their occupation. Retrospectively case files along with death certificates of 432 patients of primary malignant brain tumors and 457 controls (non-tumor neurologic diseases), admitted for treatment simultaneously over a period of 4 years from January 2005 to December 2008, to the Department of Neurosurgery, Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Kashmir, were studied. Follow-up and family contact was established. The serum cholinesterase activity was measured by kinetic/DGKC calorimetric method and ethylenediaminetetraacetic acid (EDTA) samples were sent to the laboratory. The results are expressed in U/l which is U/l×1000. The laboratory at SKIMS, Srinagar, and Dr Lal PathLabs at New Delhi used a reference range for serum cholinesterase as 3167-6333 U/l. Analysis revealed that 90.04% (389 out of 432) patients were orchard-farm workers, orchard residents and orchard playing children exposed to the high levels of multiple types of neurotoxic and carcinogenic (chlorpyriphos, dimethoate, mancozeb and captan) chemicals for more than 10-20 years. About 31.9% (124 out of 389) of these from both sexes were younger than 40 years beginning exposure at an early age and had higher (<6334 U/l) serum cholinesterase (SCE) levels. The 9.96% (43 out of 432) patients were not exposed to pesticides. On the other hand, only 119 patients out of 457 controls had recorded history of pesticide exposure and 338 were unrelated to pesticides. Out of 389 patients, 71

76 FR 2112 - Peach Orchard Road Groundwater Plume Site, Augusta, Richmond County, GA; Notice of Settlement

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... ENVIRONMENTAL PROTECTION AGENCY [Docket EPA-RO4-SFUND-2010-0965 FRL-9251-5] Peach Orchard Road... Orchard Road Groundwater Plume Site located in Augusta, Richmond County, Georgia for publication. DATES..., identified by Docket ID No. EPA-RO4- SFUND-2010-0965 or Site name Peach Orchard Road Groundwater Plume...

Photographic Remote Sensing of Sick Citrus Trees

NASA Technical Reports Server (NTRS)

Gausman, H. W.

1971-01-01

Remote sensing with infrared color aerial photography (Kodak Ektachrome Infrared Aero 8443 film) for detecting citrus tree anomalies is described. Illustrations and discussions are given for detecting nutrient toxicity symptoms, for detecting foot rot and sooty mold fungal diseases, and for distinguishing among citrus species. Also, the influence of internal leaf structure on light reflectance, transmittance, and absorptance are considered; and physiological and environmental factors that affect citrus leaf light reflectance are reviewed briefly and illustrated.

Deep Sequencing Analysis of RNAs from Citrus Plants Grown in a Citrus Sudden Death-Affected Area Reveals Diverse Known and Putative Novel Viruses.

PubMed

Matsumura, Emilyn E; Coletta-Filho, Helvecio D; Nouri, Shahideh; Falk, Bryce W; Nerva, Luca; Oliveira, Tiago S; Dorta, Silvia O; Machado, Marcos A

2017-04-24

Citrus sudden death (CSD) has caused the death of approximately four million orange trees in a very important citrus region in Brazil. Although its etiology is still not completely clear, symptoms and distribution of affected plants indicate a viral disease. In a search for viruses associated with CSD, we have performed a comparative high-throughput sequencing analysis of the transcriptome and small RNAs from CSD-symptomatic and -asymptomatic plants using the Illumina platform. The data revealed mixed infections that included Citrus tristeza virus (CTV) as the most predominant virus, followed by the Citrus sudden death-associated virus (CSDaV), Citrus endogenous pararetrovirus (CitPRV) and two putative novel viruses tentatively named Citrus jingmen-like virus (CJLV), and Citrus virga-like virus (CVLV). The deep sequencing analyses were sensitive enough to differentiate two genotypes of both viruses previously associated with CSD-affected plants: CTV and CSDaV. Our data also showed a putative association of the CSD-symptomatic plants with a specific CSDaV genotype and a likely association with CitPRV as well, whereas the two putative novel viruses showed to be more associated with CSD-asymptomatic plants. This is the first high-throughput sequencing-based study of the viral sequences present in CSD-affected citrus plants, and generated valuable information for further CSD studies.

Pest Control and Related Orchard Practices in Commercial Fruit Plantings. Circular 1151.

ERIC Educational Resources Information Center

Ries, S. M.; And Others

This circular brings together suggestions from the Illinois Agricultural Experiment Station and the Illinois State Natural History Survey relating to orchard practices and pest control. It provides some basic steps in pest control and discusses some specific orchard pests such as grasshoppers, mites, mice, and rabbits. In addition, it gives some…

Evaluation of monitoring traps with novel bait for navel orangeworm (Lepidoptera: Pyralidae) in California almond and pistachio orchards.

PubMed

Nay, Justin E; Peterson, Elonce M; Boyd, Elizabeth A

2012-08-01

Experiments conducted in three almond, Prunus dulcis (Rosales: Rosaceae), orchards and three pistachio, Pistacia vera (Sapindales: Anicardiaceae), orchards in 2009 and 2010, and determined that sticky bottom wing traps baited with ground pistachio mummies, or a combination of ground pistachio plus ground almond mummies, trapped more adult female navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), than did traps baited with ground almond mummies alone. During both years of this study, 2.9 and 1.8 more moths were caught in traps baited with pistachio mummies compared with traps baited with almond mummies in almond orchards and pistachio orchards, respectively. Also, traps located in pistachio orchards caught 5.9 and 8.3 times more navel orangeworm than were trapped from almond orchards in 2009 and 2010, respectively. Implications for use of this novel baited trap in almond and pistachio orchard integrated pest management programs are discussed.

Anatomical and Physiological Responses of Citrus Trees to Varying Boron Availability Are Dependent on Rootstock.

PubMed

Mesquita, Geisa L; Zambrosi, Fernando C B; Tanaka, Francisco A O; Boaretto, Rodrigo M; Quaggio, José A; Ribeiro, Rafael V; Mattos, Dirceu

2016-01-01

In Citrus, water, nutrient transport and thereby fruit production, are influenced among other factors, by the interaction between rootstock and boron (B) nutrition. This study aimed to investigate how B affects the anatomical structure of roots and leaves as well as leaf gas exchange in sweet orange trees grafted on two contrasting rootstocks in response to B supply. Plants grafted on Swingle citrumelo or Sunki mandarin were grown in a nutrient solution of varying B concentration (deficient, adequate, and excessive). Those grafted on Swingle were more tolerant to both B deficiency and toxicity than those on Sunki, as revealed by higher shoot and root growth. In addition, plants grafted on Sunki exhibited more severe anatomical and physiological damages under B deficiency, showing thickening of xylem cell walls and impairments in whole-plant leaf-specific hydraulic conductance and leaf CO2 assimilation. Our data revealed that trees grafted on Swingle sustain better growth under low B availablitlity in the root medium and still respond positively to increased B levels by combining higher B absorption and root growth as well as better organization of xylem vessels. Taken together, those traits improved water and B transport to the plant canopy. Under B toxicity, Swingle rootstock would also favor plant growth by reducing anatomical and ultrastructural damage to leaf tissue and improving water transport compared with plants grafted on Sunki. From a practical point of view, our results highlight that B management in citrus orchards shall take into account rootstock varieties, of which the Swingle rootstock was characterized by its performance on regulating anatomical and ultrastructural damages, improving water transport and limiting negative impacts of B stress conditions on plant growth.

Homologues of CsLOB1 in citrus function as disease susceptibility genes in citrus canker.

PubMed

Zhang, Junli; Huguet-Tapia, Jose Carlos; Hu, Yang; Jones, Jeffrey; Wang, Nian; Liu, Sanzhen; White, Frank F

2017-08-01

The lateral organ boundary domain (LBD) genes encode a group of plant-specific proteins that function as transcription factors in the regulation of plant growth and development. Citrus sinensis lateral organ boundary 1 (CsLOB1) is a member of the LBD family and functions as a disease susceptibility gene in citrus bacterial canker (CBC). Thirty-four LBD members have been identified from the Citrus sinensis genome. We assessed the potential for additional members of LBD genes in citrus to function as surrogates for CsLOB1 in CBC, and compared host gene expression on induction of different LBD genes. Using custom-designed transcription activator-like (TAL) effectors, two members of the same clade as CsLOB1, named CsLOB2 and CsLOB3, were found to be capable of functioning similarly to CsLOB1 in CBC. RNA sequencing and quantitative reverse transcription-polymerase chain reaction analyses revealed a set of cell wall metabolic genes that are associated with CsLOB1, CsLOB2 and CsLOB3 expression and may represent downstream genes involved in CBC. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Effect of Nigerian citrus (Citrus sinensis Osbeck) honey on ethanol metabolism.

PubMed

Onyesom, I

2004-12-01

The effect of Nigerian citrus (Citrus sinensis Osbeck) honey on ethanol metabolism was tested using 45 consenting individuals in apparent good health and between the ages of 25 and 35 years. The subjects were moderate social drinkers matched in terms of body weight and build. The results obtained showed that on average, honey significantly (p < 0.05) increased the blood ethanol clearance rate by 68% and decreased the intoxication period by 43%, but insignificantly (p > 0.05) reduced the degree of intoxication by 9%. Honey could be a promising anti-intoxicating agent, but its long-term biochemical evaluation, possibly as a complement in the management of alcohol intoxication, deserves further study.

The Distribution of Coumarins and Furanocoumarins in Citrus Species Closely Matches Citrus Phylogeny and Reflects the Organization of Biosynthetic Pathways

PubMed Central

Dugrand-Judek, Audray; Olry, Alexandre; Hehn, Alain; Costantino, Gilles; Ollitrault, Patrick; Froelicher, Yann; Bourgaud, Frédéric

2015-01-01

Citrus plants are able to produce defense compounds such as coumarins and furanocoumarins to cope with herbivorous insects and pathogens. In humans, these chemical compounds are strong photosensitizers and can interact with medications, leading to the “grapefruit juice effect”. Removing coumarins and furanocoumarins from food and cosmetics imply additional costs and might alter product quality. Thus, the selection of Citrus cultivars displaying low coumarin and furanocoumarin contents constitutes a valuable alternative. In this study, we performed ultra-performance liquid chromatography coupled with mass spectrometry analyses to determine the contents of these compounds within the peel and the pulp of 61 Citrus species representative of the genetic diversity all Citrus. Generally, Citrus peel contains larger diversity and higher concentrations of coumarin/furanocoumarin than the pulp of the same fruits. According to the chemotypes found in the peel, Citrus species can be separated into 4 groups that correspond to the 4 ancestral taxa (pummelos, mandarins, citrons and papedas) and extended with their respective secondary species descendants. Three of the 4 ancestral taxa (pummelos, citrons and papedas) synthesize high amounts of these compounds, whereas mandarins appear practically devoid of them. Additionally, all ancestral taxa and their hybrids are logically organized according to the coumarin and furanocoumarin pathways described in the literature. This organization allows hypotheses to be drawn regarding the biosynthetic origin of compounds for which the biogenesis remains unresolved. Determining coumarin and furanocoumarin contents is also helpful for hypothesizing the origin of Citrus species for which the phylogeny is presently not firmly established. Finally, this work also notes favorable hybridization schemes that will lead to low coumarin and furanocoumarin contents, and we propose to select mandarins and Ichang papeda as Citrus varieties for use in

Population Dynamics and Flight Phenology Model of Codling Moth Differ between Commercial and Abandoned Apple Orchard Ecosystems.

PubMed

Joshi, Neelendra K; Rajotte, Edwin G; Naithani, Kusum J; Krawczyk, Greg; Hull, Larry A

2016-01-01

Apple orchard management practices may affect development and phenology of arthropod pests, such as the codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae), which is a serious internal fruit-feeding pest of apples worldwide. Estimating population dynamics and accurately predicting the timing of CM development and phenology events (for instance, adult flight, and egg-hatch) allows growers to understand and control local populations of CM. Studies were conducted to compare the CM flight phenology in commercial and abandoned apple orchard ecosystems using a logistic function model based on degree-days accumulation. The flight models for these orchards were derived from the cumulative percent moth capture using two types of commercially available CM lure baited traps. Models from both types of orchards were also compared to another model known as PETE (prediction extension timing estimator) that was developed in 1970s to predict life cycle events for many fruit pests including CM across different fruit growing regions of the United States. We found that the flight phenology of CM was significantly different in commercial and abandoned orchards. CM male flight patterns for first and second generations as predicted by the constrained and unconstrained PCM (Pennsylvania Codling Moth) models in commercial and abandoned orchards were different than the flight patterns predicted by the currently used CM model (i.e., PETE model). In commercial orchards, during the first and second generations, the PCM unconstrained model predicted delays in moth emergence compared to current model. In addition, the flight patterns of females were different between commercial and abandoned orchards. Such differences in CM flight phenology between commercial and abandoned orchard ecosystems suggest potential impact of orchard environment and crop management practices on CM biology.

Population Dynamics and Flight Phenology Model of Codling Moth Differ between Commercial and Abandoned Apple Orchard Ecosystems

PubMed Central

Joshi, Neelendra K.; Rajotte, Edwin G.; Naithani, Kusum J.; Krawczyk, Greg; Hull, Larry A.

2016-01-01

Apple orchard management practices may affect development and phenology of arthropod pests, such as the codling moth (CM), Cydia pomonella (L.) (Lepidoptera: Tortricidae), which is a serious internal fruit-feeding pest of apples worldwide. Estimating population dynamics and accurately predicting the timing of CM development and phenology events (for instance, adult flight, and egg-hatch) allows growers to understand and control local populations of CM. Studies were conducted to compare the CM flight phenology in commercial and abandoned apple orchard ecosystems using a logistic function model based on degree-days accumulation. The flight models for these orchards were derived from the cumulative percent moth capture using two types of commercially available CM lure baited traps. Models from both types of orchards were also compared to another model known as PETE (prediction extension timing estimator) that was developed in 1970s to predict life cycle events for many fruit pests including CM across different fruit growing regions of the United States. We found that the flight phenology of CM was significantly different in commercial and abandoned orchards. CM male flight patterns for first and second generations as predicted by the constrained and unconstrained PCM (Pennsylvania Codling Moth) models in commercial and abandoned orchards were different than the flight patterns predicted by the currently used CM model (i.e., PETE model). In commercial orchards, during the first and second generations, the PCM unconstrained model predicted delays in moth emergence compared to current model. In addition, the flight patterns of females were different between commercial and abandoned orchards. Such differences in CM flight phenology between commercial and abandoned orchard ecosystems suggest potential impact of orchard environment and crop management practices on CM biology. PMID:27713702

7 CFR 301.75-5 - Commercial citrus-producing areas.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Commercial citrus-producing areas. 301.75-5 Section... and Regulations § 301.75-5 Commercial citrus-producing areas. (a) The following are designated as commercial citrus-producing areas: American Samoa Arizona California Florida Guam Hawaii Louisiana Northern...

7 CFR 301.75-5 - Commercial citrus-producing areas.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 5 2014-01-01 2014-01-01 false Commercial citrus-producing areas. 301.75-5 Section... and Regulations § 301.75-5 Commercial citrus-producing areas. (a) The following are designated as commercial citrus-producing areas: American Samoa Arizona California Florida Guam Hawaii Louisiana Northern...

Expression and functional analysis of citrus carotene hydroxylases: unravelling the xanthophyll biosynthesis in citrus fruits.

PubMed

Ma, Gang; Zhang, Lancui; Yungyuen, Witchulada; Tsukamoto, Issei; Iijima, Natsumi; Oikawa, Michiru; Yamawaki, Kazuki; Yahata, Masaki; Kato, Masaya

2016-06-29

Xanthophylls are oxygenated carotenoids and fulfill critical roles in plant growth and development. In plants, two different types of carotene hydroxylases, non-heme di-iron and heme-containing cytochrome P450, were reported to be involved in the biosynthesis of xanthophyll. Citrus fruits accumulate a high amount of xanthophylls, especially β,β-xanthophylls. To date, however, the roles of carotene hydroxylases in regulating xanthophyll content and composition have not been elucidated. In the present study, the roles of four carotene hydroxylase genes (CitHYb, CitCYP97A, CitCYP97B, and CitCYP97C) in the biosynthesis of xanthophyll in citrus fruits were investigated. Phylogenetic analysis showed that the four citrus carotene hydroxylases presented in four distinct clusters which have been identified in higher plants. CitHYb was a non-heme di-iron carotene hydroxylase, while CitCYP97A, CitCYP97B, and CitCYP97C were heme-containing cytochrome P450-type carotene hydroxylases. Gene expression results showed that the expression of CitHYb increased in the flavedo and juice sacs during the ripening process, which was well consistent with the accumulation of β,β-xanthophyll in citrus fruits. The expression of CitCYP97A and CitCYP97C increased with a peak in November, which might lead to an increase of lutein in the juice sacs during the ripening process. The expression level of CitCYP97B was much lower than that of CitHYb, CitCYP97A, and CitCYP97C in the juice sacs during the ripening process. Functional analysis showed that the CitHYb was able to catalyze the hydroxylation of the β-rings of β-carotene and α-carotene in Escherichia coli BL21 (DE3) cells. Meanwhile, when CitHYb was co-expressed with CitCYP97C, α-carotene was hydroxylated on the β-ring and ε-ring sequentially to produce lutein. CitHYb was a key gene for β,β-xanthophyll biosynthesis in citrus fruits. CitCYP97C functioned as an ε-ring hydroxylase to produce lutein using zeinoxanthin as a substrate

Development of a simple and rapid reverse transcription-loop mediated isothermal amplification (RT-LAMP) assay for sensitive detection of Citrus tristeza virus.

PubMed

Warghane, Ashish; Misra, Pragati; Bhose, Sumit; Biswas, Kajal Kumar; Sharma, Ashwani Kumar; Reddy, M Krishna; Ghosh, Dilip Kumar

2017-12-01

Tristeza is a devastating disease of citrus and reported to be present in almost all countries where it is cultivated as a commercial crop. The etiological agent of this disease is Citrus tristeza virus (CTV), a member of the genus Closterovirus with in the family Closteroviridae. The pathogen is restricted to the phloem tissue of the infected citrus plant and has a monopartite ss (+) RNA genome of ∼20kb size. Till date, there is no effective control measure available for this virus. Management of tristeza depends on destruction of CTV infected field plants, production of virus-free planting material for new orchard establishment and controlling viruliferous aphid vectors responsible for field spread of the pathogen. Availability of rapid diagnostic assay is essential for rapid and efficient detection of the pathogen. In the present investigation, RT-LAMP (reverse transcription-loop mediated isothermal amplification), a highly sensitive, robust and low cost assay has been developed for rapid detection of CTV in infected citrus plant samples. Based on conserved nucleotide sequences available in GenBank and specific to p25 gene (major coat protein gene) of predominant CTV isolates of India, four primer sets (CTV-F3, CTV-B3, CTV-FIP and CTV-BIP) ware designed and custom synthesized. The amplified LAMP products obtained after maintaining isothermal condition of 65°C for 60min duration could be visible easily with necked eyes in presence of SYBR Green I (100X). Subsequently, LAMP products were verified by electrophoresis run in 1.5% agarose gel. The RT-LAMP results obtained with known CTV isolates maintained in screen house of CCRI, Nagpur were validated using field samples and thereafter it was further confirmed by conventional RT-PCR (reveres transcription-polymerase chain reaction) assay. The sensitivity of CTV-RT-LAMP protocol standardized in the present study was 100 times more than conventional one step RT-PCR assay. It also has maximum detection limit up to 0

Evaluating citrus germplasm for huanglongbing (HLB) resistance: USDA-ARS Inoculation Program

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it vectors bacteria responsible for a serious disease of citrus known as huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program for screening citrus germplasm for resistance to the di...

Mechanical Damage Detection of Indonesia Local Citrus Based on Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Siregar, T. H.; Ahmad, U.; Sutrisno; Maddu, A.

2018-05-01

Citrus experienced physical damage in peel will produce essential oils that contain polymethoxylated flavone. Polymethoxylated flavone is fluorescence substance; thus can be detected by fluorescence imaging. This study aims to study the fluorescence spectra characteristic and to determine the damage region in citrus peel based on fluorescence image. Pulung citrus from Batu district, East Java, as a famous citrus production area in Indonesia, was used in the experiment. It was observed that the image processing could detect the mechanical damage region. Fluorescence imaging can be used to classify the citrus into two categories, sound and defect citruses.

Huanglongbing increases Diplodia Stem End Rot in Citrus sinensis

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB), one of the most devastating diseases of citrus is caused by the a-Proteobacteria Candidatus Liberibacter. Diplodia natalensis Pole-Evans is a fungal pathogen which has been known to cause a postharvest stem-end rot of citrus, the pathogen infects citrus fruit under the calyx, an...

Mechanisms of copper stress alleviation in Citrus trees after metal uptake by leaves or roots.

PubMed

Hippler, Franz Walter Rieger; Petená, Guilherme; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Azevedo, Ricardo Antunes; Mattos-Jr, Dirceu

2018-05-01

Nutritional disorders caused by copper (Cu) have affected citrus orchards. Since Cu is foliar sprayed as a pesticide to control citrus diseases, this metal accumulates in the soil. Thereby, we evaluated the effects of Cu leaf absorption after spray of different metal sources, as well as roots absorption on growth, nutritional status, and oxidative stress of young sweet orange trees. Two experiments were carried out under greenhouse conditions. The first experiment was set up with varying Cu levels to the soil (nil Cu, 0.5, 2.0, 4.0 and 8.0 g of Cu per plant as CuSO 4 .5H 2 O), whereas the second experiment with Cu application via foliar sprays (0.5 and 2.0 g of Cu per plant) and comparing two metal sources (CuSO 4 .5H 2 O or Cu(OH) 2 ). Copper was mainly accumulated in roots with soil supply, but an increase of oxidative stress levels was observed in leaves. On the other hand, Cu concentrations were higher in leaves that received foliar sprays, mainly as Cu(OH) 2 . However, when sulfate was foliar sprayed, plants exhibited more symptoms of injuries in the canopy with decreased chlorophyll contents and increased hydrogen peroxide and lipid peroxidation levels. Copper toxicity was characterized by sap leakage from the trunk and twigs, which is the first report of this specific Cu excess symptom in woody trees. Despite plants with 8.0 g of Cu soil-applied exhibiting the sap leakage, growth of new plant parts was more vigorous with lower oxidative stress levels and injuries compared to those with 4.0 g of Cu soil-applied (without sap leakage). With the highest level of Cu applied via foliar as sulfate, Cu was eliminated by plant roots, increasing the rhizospheric soil metal levels. Despite citrus likely exhibiting different mechanisms to reduce the damages caused by metal toxicity, such as responsive enzymatic antioxidant system, metal accumulation in the roots, and metal exclusion by roots, excess Cu resulted in damages on plant growth and metabolism when the

Pesticides and brain cancer linked in orchard farmers of Kashmir

PubMed Central

Bhat, Abdul Rashid; Wani, Muhammed Afzal; Kirmani, A. R.; Raina, T. H.

2010-01-01

Background: The atmosphere of valley of Kashmir is ideal for fresh and dry fruit production. Millions of tons of pesticides, insecticides and fungicides (chemicals like chlorpyriphos, mancozeb, captan, dimethoate, phosalone, etc.) are being used by the orchard farmers to spray the plants, fruits and the leaves every year. The increasing trend in the incidence of primary malignant brain tumors in orchard farmers of Kashmir is alarming. Aim: To determine the relationship between the patients of primary malignant brain tumors and their occupation. Materials and Methods: Retrospectively case files along with death certificates of 432 patients of primary malignant brain tumors and 457 controls (non-tumor neurologic diseases), admitted for treatment simultaneously over a period of 4 years from January 2005 to December 2008, to the Department of Neurosurgery, Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Kashmir, were studied. Follow-up and family contact was established. The serum cholinesterase activity was measured by kinetic/DGKC calorimetric method and ethylenediaminetetraacetic acid (EDTA) samples were sent to the laboratory. The results are expressed in U/l which is U/l×1000. The laboratory at SKIMS, Srinagar, and Dr Lal PathLabs at New Delhi used a reference range for serum cholinesterase as 3167–6333 U/l. Results: Analysis revealed that 90.04% (389 out of 432) patients were orchard-farm workers, orchard residents and orchard playing children exposed to the high levels of multiple types of neurotoxic and carcinogenic (chlorpyriphos, dimethoate, mancozeb and captan) chemicals for more than 10–20 years. About 31.9% (124 out of 389) of these from both sexes were younger than 40 years beginning exposure at an early age and had higher (<6334 U/l) serum cholinesterase (SCE) levels. The 9.96% (43 out of 432) patients were not exposed to pesticides. On the other hand, only 119 patients out of 457 controls had recorded history of pesticide exposure and 338

Quantitation of flavonoid constituents in citrus fruits.

PubMed

Kawaii, S; Tomono, Y; Katase, E; Ogawa, K; Yano, M

1999-09-01

Twenty-four flavonoids have been determined in 66 Citrus species and near-citrus relatives, grown in the same field and year, by means of reversed phase high-performance liquid chromatography analysis. Statistical methods have been applied to find relations among the species. The F ratios of 21 flavonoids obtained by applying ANOVA analysis are significant, indicating that a classification of the species using these variables is reasonable to pursue. Principal component analysis revealed that the distributions of Citrus species belonging to different classes were largely in accordance with Tanaka's classification system.

Evaluation of Daily Evapotranspiration Over Orchards Using METRIC Approach and Landsat Satellite Observations

NASA Astrophysics Data System (ADS)

He, R.; Jin, Y.; Daniele, Z.; Kandelous, M. M.; Kent, E. R.

2016-12-01

The pistachio and almond acreage in California has been rapidly growing in the past 10 years, raising concerns about competition for limited water resources in California. A robust and cost-effective mapping of crop water use, mostly evapotranspiration (ET), by orchards, is needed for improved farm-level irrigation management and regional water planning. METRIC™, a satellite-based surface energy balance approach, has been widely used to map field-scale crop ET, mostly over row crops. We here aim to apply METRIC with Landsat satellite observations over California's orchards and evaluate the ET estimates by comparing with field measurements in South San Joaquin Valley, California. Reference ET of grass (ETo) from California Irrigation Management Information system (CIMIS) stations was used to estimate daily ET of commercial almond and pistachio orchards. Our comparisons showed that METRIC-Landsat ET daily estimates agreed well with ET measured by the eddy covariance and surface renewal stations, with a RMSE of 1.25 and a correlation coefficient of 0.84 for the pistachio orchard. A slight high bias of satellite based ET estimates was found for both pistachio and almond orchards. We also found time series of NDVI was highly correlated with ET temporal dynamics within each field, but the correlation was reduced to 0.56 when all fields were pooled together. Net radiation, however, remained highly correlated with ET across all the fields. The METRIC ET was able to distinguish the differences in ET among salt- and non-salt affected pistachio orchards, e.g., mean daily ET during growing season in salt-affected orchards was lower than that of non-salt affected one by 0.87 mm/day. The remote sensing based ET estimate will support a variety of state and local interests in water use and management, for both planning and regulatory/compliance purposes, and provide the farmers observation-based guidance for site-specific and time-sensitive irrigation management.

Enhancement of β-Carotene Synthesis by Citrus Products

PubMed Central

Ciegler, Alex; Nelson, George E. N.; Hall, Harlow H.

1963-01-01

β-Ionone, a stimulatory compound in the microbiological production of β-carotene by mated cultures of Blakeslea trispora, could be replaced with low-cost agricultural by-products (citrus oils, citrus pulp, or citrus molasses) with as good or better carotene yields. Peak yields (81 to 129 mg of carotene per g of dry solids) were achieved in 5 days. The various citrus products tested did not change the pigments produced; all trans-β-carotene remained the pre-dominant pigment. The acid-hydrolyzed soybean meal and corn used in previous production media could be replaced with unhydrolyzed cottonseed embryo meal and corn in a medium that also contained a natural lipid, deodorized kerosene, nonionic detergent, and a precursor. PMID:14021337

Citrus peel extract incorporated ice cubes to protect the quality of common pandora: Fish storage in ice with citrus.

PubMed

Yerlikaya, Pinar; Ucak, Ilknur; Gumus, Bahar; Gokoglu, Nalan

2015-12-01

The objective of this study was to investigate the effects of ice with albedo and flavedo fragments of Citrus (Grapefruit (Citrus paradisi) and Bitter orange (Citrus aurantium L.)) extracts on the quality of common pandora (Pagellus erythrinus). Concentrated citrus extracts were diluted with distilled water (1/100 w/v) before making of ice. The ice cubes were spread on each layer of fishes and stored at 0 °C for 15 days. The pH value showed a regular increase in all samples. TVB-N levels of bitter orange treatment groups were recorded lower than the other groups reaching to 25.11 ± 0.02 mg/100 g at the end of the storage. The TMA-N values of bitter orange treatment groups were lower than that of control and grapefruit treatment groups. In terms of TBARS value, alteration was observed in the control samples and this value significantly (p < 0.01) increased from 0.101 ± 0.011 mg MA/kg to 0.495 ± 0.083 mg MA/kg, while remained lower in the citrus extracts treatment groups at the end of storage since their antioxidant capacity. The oxidation was suppressed in citrus extracts treatment groups, especially in bitter orange flavedo treatment. The results showed the bitter orange albedo and bitter orange flavedo extracts in combination with ice storage have more effectiveness in controlling the biochemical indices in common pandora.

Immunoblotting Quantification Approach for Identifying Potential Hypoallergenic Citrus Cultivars.

PubMed

Wu, Jinlong; Deng, Wenjun; Lin, Dingbo; Deng, Xiuxin; Ma, Zhaocheng

2018-02-28

The inherent allergens of citrus fruits, such as Cit s 1, Cit s 2, Cit s 3 can cause allergic reactions. A better understanding of the genetic factors (cultivar to cultivar) affecting the allergenic potential of citrus fruits would be beneficial for further identification of hypoallergenic genotypes. In the present study, an immunoblotting quantification approach was adopted to assess the potential allergenicity of 21 citrus cultivars, including nine subgroups (tangerine, satsuma, orange, pummelo, grapefruit, lemon, kumquat, tangor, and tangelo). To prepare highly sensitive and specific rabbit polyclonal antibodies, antigenicity of purified rCit s 1.01, rCit s 2.01, and rCit s 3.01 peptides were enhanced with high epitope density in a single protein molecule. The data integration of three citrus allergen quantifications demonstrated that the four pummelo cultivars (Kao Phuang Pummelo, Wanbai Pummelo, Shatian Pummelo, and Guanxi Pummelo) were potential hypoallergenic, compared with other 8 subgroups. Moreover, the immunological analyses with sera of allergic subjects revealed that Shatian Pummelo and Guanxi Pummelo showed the lowest immunoreactivity in 8 representative citrus cultivars. These potential hypoallergenic genotypes are of great significance to not only allergic consumers but also citrus breeders in the genetic improvement of hypoallergenic citrus as breeding resources.

Bioavailable Citrus sinensis Extract: Polyphenolic Composition and Biological Activity.

PubMed

Pepe, Giacomo; Pagano, Francesco; Adesso, Simona; Sommella, Eduardo; Ostacolo, Carmine; Manfra, Michele; Chieppa, Marcello; Sala, Marina; Russo, Mariateresa; Marzocco, Stefania; Campiglia, Pietro

2017-04-15

Citrus plants contain large amounts of flavonoids with beneficial effects on human health. In the present study, the antioxidant and anti-inflammatory potential of bioavailable polyphenols from Citrus sinensis was evaluated in vitro and ex vivo, using the murine macrophages cell line J774A.1 and primary peritoneal macrophages. Following simulated gastro-intestinal digestion, the in vitro bioavailability of Citrus sinensis polyphenolic extract was assessed using the human cell line Caco-2 grown as monolayers on a transwell membrane. Data demonstrated a relative permeation of its compounds (8.3%). Thus, the antioxidant and anti-inflammatory effect of polyphenolic Citrus sinensis fraction (Cs) was compared to the bioavailable one (CsB). Results revealed that Citrus extract were able to reduce macrophages pro-inflammatory mediators, including nitric oxide, iNOS, COX-2 and different cytokines. Moreover, the effect of Citrus sinensis polyphenols was associated with antioxidant effects, such as a reduction of reactive oxygen species (ROS) and heme-oxygenase-1 (HO-1) increased expression. Our results provide evidence that the bioavailable polyphenolic constituents of the Citrus sinensis extract accumulate prevalently at intestinal level and could reach systemic circulation exerting their effect. The bioavailable fraction showed a higher anti-inflammatory and antioxidant potential compared to the initial extract, thus highlighting its potential nutraceutical value.

Assessment of the soil water balance by the combination of cosmic ray neutron sensing and eddy covariance technique in an irrigated citrus orchard (Marrakesh, Morocco)

NASA Astrophysics Data System (ADS)

Mroos, Katja; Baroni, Gabriele; Er-Raki, Salah; Francke, Till; Khabba, Said; Jarlan, Lionel; Hanich, Lahoucine; Oswald, Sascha E.

2014-05-01

Irrigation water requirement plays a crucial role in many agricultural areas and especially in arid and semi-arid landscapes. Improvements in the water management and the performance of the irrigation systems require a correct evaluation of the hydrological processes involved. However, some difficulties can arise due to the heterogeneity of the soil-plant system and of the irrigation scheme. To overcome these limitations, in this study, the soil water balance is analyzed by the combination of the Eddy Covariance technique (EC) and Cosmic Ray neutron Sensing (CRS). EC provides the measurement of the actual evapotranspiration over the area as it was presented in many field conditions. Moreover CRS showed to be a valuable approach to measure the root zone soil moisture integrated in a footprint of ~30 ha. In this way, the combination of the two methodologies should provide a better analysis of the soil water balance at field scale, as opposed to point observations, e.g. by TDR, evaporimeter and fluxmeter. Then, this could increase the capability to assess the irrigation efficiency and the agricultural water management. The study is conducted in a citrus orchard situated in a semi-arid region, 30 km southwest of Marrakesh (Morocco). The site is flat and planted with trees of same age growing in parallel rows with drip irrigation lines and application of fertilizer and pesticides. The original soil seems modified on the surface by the agricultural use, creating differences between trees, rows and lines. In addition, the drip irrigation creates also a spatial variability of the water flux distribution in the field, making this site an interesting area to test the methodology. Particular attention is given to the adaptation of the standard soil sampling campaign used for the calibration of the CRS and the introduction of a weighing function. Data were collected from June to December 2013, which corresponds to the high plant transpiration. Despite the intention of the

Costs and benefits of insecticide and foliar nutrient applications to huanglongbing-infected citrus trees.

PubMed

Tansey, James A; Vanaclocha, Pilar; Monzo, Cesar; Jones, Moneen; Stansly, Philip A

2017-05-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Psyllidae), vectors Candidatus Liberibacter asiaticus, which causes huanglongbing (HLB). In Florida, HLB incidence is approaching 100% statewide. Yields have decreased and production costs have increased since 2005. Despite this, some growers are maintaining a level of production and attribute this in part to aggressive psyllid control and foliar nutrition sprays. However, the value of these practices is debated. A replicated field study was initiated in 2008 in a commercial block of 'Valencia' sweet orange trees to evaluate individual and combined effects of foliar nutrition and ACP control. Results from 2012-2016 are presented. Insecticides consistently reduced ACP populations. However, neither insecticide nor nutrition applications significantly influenced HLB incidence or PCR copy number in mature trees. In reset trees, infection continued to build and reached 100% in all treatments. Greatest yields (kg fruit ha -1 ) and production (kg solids ha -1 ) were obtained from trees receiving both insecticides and foliar nutrition. All treatments resulted in production and financial gains relative to controls. However, material and application costs associated with the nutrition component offset these gains, resulting in lesser benefits than insecticides applied alone. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Dietary citrus pulp reduces lipid oxidation in lamb meat.

PubMed

Inserra, L; Priolo, A; Biondi, L; Lanza, M; Bognanno, M; Gravador, R; Luciano, G

2014-04-01

This study investigated the effect of replacing cereal concentrates with high levels of dried citrus pulp in the diet on lamb meat oxidative stability. Over 56 days, lambs were fed a barley-based concentrate (Control) or concentrates in which 24% and 35% dried citrus pulp were included to partially replace barley (Citrus 24% and Citrus 35%, respectively). Meat was aged under vacuum for 4 days and subsequently stored aerobically at 4 °C. The Control diet increased the redness, yellowness and saturation of meat after blooming (P<0.01). Regardless of the level of supplementation, dietary dried citrus pulp strongly reduced meat lipid oxidation over 6 days of aerobic storage (P<0.001), while colour parameters did not change noticeably over storage and their variation rate was not affected by the diet. In conclusion, replacing cereals with dried citrus pulp in concentrate-based diets might represent a feasible strategy to naturally improve meat oxidative stability and to promote the exploitation of this by-product. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cotyledon density measurements on valencia peanuts grown in the Southwest United States as a tool for developing food products

USDA-ARS?s Scientific Manuscript database

Valencia peanuts (Arachis hypogaea L. ssp. fastigiata) are able to complete seed development in an environment where extreme temperature variation and water deficit are common and growing season is short. Valencia seed can command a premium in food products as consumers like special properties like...

Expression patterns of flowering genes in leaves of 'Pineapple' sweet orange [Citrus sinensis (L.) Osbeck] and pummelo (Citrus grandis Osbeck).

PubMed

Pajon, Melanie; Febres, Vicente J; Moore, Gloria A

2017-08-30

In citrus the transition from juvenility to mature phase is marked by the capability of a tree to flower and fruit consistently. The long period of juvenility in citrus severely impedes the use of genetic based strategies to improve fruit quality, disease resistance, and responses to abiotic environmental factors. One of the genes whose expression signals flower development in many plant species is FLOWERING LOCUS T (FT). In this study, gene expression levels of flowering genes CiFT1, CiFT2 and CiFT3 were determined using reverse-transcription quantitative real-time PCR in citrus trees over a 1 year period in Florida. Distinct genotypes of citrus trees of different ages were used. In mature trees of pummelo (Citrus grandis Osbeck) and 'Pineapple' sweet orange (Citrus sinensis (L.) Osbeck) the expression of all three CiFT genes was coordinated and significantly higher in April, after flowering was over, regardless of whether they were in the greenhouse or in the field. Interestingly, immature 'Pineapple' seedlings showed significantly high levels of CiFT3 expression in April and June, while CiFT1 and CiFT2 were highest in June, and hence their expression induction was not simultaneous as in mature plants. In mature citrus trees the induction of CiFTs expression in leaves occurs at the end of spring and after flowering has taken place suggesting it is not associated with dormancy interruption and further flower bud development but is probably involved with shoot apex differentiation and flower bud determination. CiFTs were also seasonally induced in immature seedlings, indicating that additional factors must be suppressing flowering induction and their expression has other functions.

CsPLDalpha1 and CsPLDgamma1 are differentially induced during leaf and fruit abscission and diurnally regulated in Citrus sinensis.

PubMed

Malladi, Anish; Burns, Jacqueline K

2008-01-01

Understanding leaf and fruit abscission is essential in order to develop strategies for controlling the process in fruit crops. Mechanisms involved in signalling leaf and fruit abscission upon induction by abscission agents were investigated in Citrus sinensis cv. 'Valencia'. Previous studies have suggested a role for phospholipid signalling; hence, two phospholipase D cDNA sequences, CsPLDalpha1 and CsPLDgamma1, were isolated and their role was examined. CsPLDalpha1 expression was reduced in leaves but unaltered in fruit peel tissue treated with an ethylene-releasing compound (ethephon), or a fruit-specific abscission agent, 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP). By contrast, CsPLDgamma1 expression was up-regulated within 6 h (leaves) and 24 h (fruit peel) after treatment with ethephon or CMNP, respectively. CsPLDalpha1 expression was diurnally regulated in leaf blade but not fruit peel. CsPLDgamma1 exhibited strong diurnal oscillation in expression in leaves and fruit peel with peak expression around midday. While diurnal fluctuation in CsPLDalpha1 expression appeared to be light-entrained in leaves, CsPLDgamma1 expression was regulated by light and the circadian clock. The diurnal expression of both genes was modulated by ethylene-signalling. The ethephon-induced leaf abscission and the ethephon- and CMNP-induced decrease in fruit detachment force were enhanced by application during rising diurnal expression of CsPLDgamma1. The results indicate differential regulation of CsPLDalpha1 and CsPLDgamma1 in leaves and fruit, and suggest possible roles for PLD-dependent signalling in regulating abscission responses in citrus.

Resistance and tolerance to Huanglongbing in citrus

USDA-ARS?s Scientific Manuscript database

The Stover-led research team focuses on developing improved citrus scion varieties, through both conventional breeding and transgenics, with special attention to confronting the threat of citrus huanglongbing (HLB). Collaborations are underway with more than 20 research groups around the world to ha...

Guiding Classical Biological Control of an Invasive Mealybug Using Integrative Taxonomy

PubMed Central

Beltrà, Aleixandre; Addison, Pia; Ávalos, Juan Antonio; Crochard, Didier; Garcia-Marí, Ferran; Guerrieri, Emilio; Giliomee, Jan H.; Malausa, Thibaut; Navarro-Campos, Cristina; Palero, Ferran; Soto, Antonia

2015-01-01

Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is a mealybug of Southern African origin that has recently been introduced into Eastern Spain. It causes severe distortions on young citrus fruits and represents a growing threat to Mediterranean citrus production. So far, biological control has proven unsatisfactory due to the absence of efficient natural enemies in Spain. Hence, the management of this pest currently relies only on chemical control. The introduction of natural enemies of D. aberiae from the native area of the pest represents a sustainable and economically viable alternative to reduce the risks linked to pesticide applications. Since biological control of mealybugs has been traditionally challenged by taxonomic misidentification, an intensive survey of Delottococcus spp. and their associated parasitoids in South Africa was required as a first step towards a classical biological control programme. Combining morphological and molecular characterization (integrative taxonomy) a total of nine mealybug species were identified in this study, including three species of Delottococcus. Different populations of D. aberiae were found on wild olive trees, in citrus orchards and on plants of Chrysanthemoides monilifera, showing intra-specific divergences according to their host plants. Interestingly, the invasive mealybug populations from Spanish orchards clustered together with the population on citrus from Limpopo Province (South Africa), sharing COI haplotypes. This result pointed to an optimum location to collect natural enemies against the invasive mealybug. A total of 14 parasitoid species were recovered from Delottococcus spp. and identified to genus and species level, by integrating morphological and molecular data. A parasitoid belonging to the genus Anagyrus, collected from D. aberiae in citrus orchards in Limpopo, is proposed here as a good biological control agent to be introduced into Spain. PMID:26047349

Economic injury levels for Asian citrus psyllid control in process oranges from mature trees with high incidence of huanglongbing

PubMed Central

Monzo, Cesar; Stansly, Philip A.

2017-01-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the key pest of citrus wherever it occurs due to its role as vector of huanglongbing (HLB) also known as citrus greening disease. Insecticidal vector control is considered to be the primary strategy for HLB management and is typically intense owing to the severity of this disease. While this approach slows spread and also decreases severity of HLB once the disease is established, economic viability of increasingly frequent sprays is uncertain. Lacking until now were studies evaluating the optimum frequency of insecticide applications to mature trees during the growing season under conditions of high HLB incidence. We related different degrees of insecticide control with ACP abundance and ultimately, with HLB-associated yield losses in two four-year replicated experiments conducted in commercial groves of mature orange trees under high HLB incidence. Decisions on insecticide applications directed at ACP were made by project managers and confined to designated plots according to experimental design. All operational costs as well as production benefits were taken into account for economic analysis. The relationship between management costs, ACP abundance and HLB-associated economic losses based on current prices for process oranges was used to determine the optimum frequency and timing for insecticide applications during the growing season. Trees under the most intensive insecticidal control harbored fewest ACP resulting in greatest yields. The relationship between vector densities and yield loss was significant but differed between the two test orchards, possibly due to varying initial HLB infection levels, ACP populations or cultivar response. Based on these relationships, treatment thresholds during the growing season were obtained as a function of application costs, juice market prices and ACP densities. A conservative threshold for mature trees with high incidence of HLB would help maintain economic

Economic injury levels for Asian citrus psyllid control in process oranges from mature trees with high incidence of huanglongbing.

PubMed

Monzo, Cesar; Stansly, Philip A

2017-01-01

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is the key pest of citrus wherever it occurs due to its role as vector of huanglongbing (HLB) also known as citrus greening disease. Insecticidal vector control is considered to be the primary strategy for HLB management and is typically intense owing to the severity of this disease. While this approach slows spread and also decreases severity of HLB once the disease is established, economic viability of increasingly frequent sprays is uncertain. Lacking until now were studies evaluating the optimum frequency of insecticide applications to mature trees during the growing season under conditions of high HLB incidence. We related different degrees of insecticide control with ACP abundance and ultimately, with HLB-associated yield losses in two four-year replicated experiments conducted in commercial groves of mature orange trees under high HLB incidence. Decisions on insecticide applications directed at ACP were made by project managers and confined to designated plots according to experimental design. All operational costs as well as production benefits were taken into account for economic analysis. The relationship between management costs, ACP abundance and HLB-associated economic losses based on current prices for process oranges was used to determine the optimum frequency and timing for insecticide applications during the growing season. Trees under the most intensive insecticidal control harbored fewest ACP resulting in greatest yields. The relationship between vector densities and yield loss was significant but differed between the two test orchards, possibly due to varying initial HLB infection levels, ACP populations or cultivar response. Based on these relationships, treatment thresholds during the growing season were obtained as a function of application costs, juice market prices and ACP densities. A conservative threshold for mature trees with high incidence of HLB would help maintain economic

How to Plant Apple Trees to Reduce Replant Disease in Apple Orchard: A Study on the Phenolic Acid of the Replanted Apple Orchard

PubMed Central

Yin, Chengmiao; Xiang, Li; Wang, Gongshuai; Wang, Yanfang; Shen, Xiang; Chen, Xuesen; Mao, Zhiquan

2016-01-01

Apple replant disease (ARD) is an important problem in the production of apple. The phenolic acid is one of the causes of ARD. How phenolic acid affects the ARD was not well known. In this study, we analyzed the type, concentration and annual dynamic variation of phenolic acid in soil from three replanted apple orchards using an accelerated solvent extraction system with high performance liquid chromatography (ASE-HPLC). We found that the type and concentration of phenolic acid were significantly differed among different seasons, different sampling positions and different soil layers. Major types of phenolic acid in three replanted apple orchards were phlorizin, benzoic acid and vanillic aldehyde. The concentration of phenolic acid was highest in the soil of the previous tree holes and it was increased from the spring to autumn. Moreover, phenolic acid was primarily distributed in 30–60 cm soil layer in the autumn, while it was most abundant in 0–30 cm soil layer in the spring. Our results suggest that phlorizin, benzoic acid and vanillic aldehyde may be the key phenolic acid that brought about ARD in the replanted apple orchard. PMID:27907081

Anti-inflammatory effects of Citrus sinensis L., Citrus paradisi L. and their combinations.

PubMed

Khan, Rafeeq Alam; Mallick, Neelam; Feroz, Zeeshan

2016-05-01

Citrus bioflavonoids embrace a wide group of phenolic compounds effecting the production and scavenging of reactive oxygen species and the processes relating free radical-mediated injury. Keeping in view of the antioxidant and anti-inflammatory properties of Citrus sinensis and Citrus paradisi, present study was undertaken to explore the effects of C. sinensis (orange juice) and C. paradisi (grapefruit juice) at three different doses alone and their two combinations with the objective to examine the effects of these compounds in an experimental model of rat colitis induced by trinitrobenzenesulphonic acid (TNBS). Hence biochemical parameters e.g. myeloperoxidase, alkaline phosphatase, C-reactive protein (CRP) and glutathione were assessed. Data entry and analysis was accomplished by Statistical Package for the Social Sciences version 17 and was presented as mean ± S.E.M with 95% confidence interval. Present result shows that these juices, mainly C. paradisi, may be efficacious for the management of inflammatory bowel disease. In acute colitis model, C. paradise encouraged a decrease in the extension of the lesion escorted by a decrease in the occurrence of diarrhea and reinstatement of the glutathione content. Related effects were produced by the administration of C. sinensis, which also prevented the myeloperoxidase and alkaline phosphatase actions in acute intestinal inflammatory process. The effect of the citrus juices on the inflammatory process may be associated to their antioxidant and anti-inflammatory properties, as revealed in present investigation. The favorable effects exerted were demonstrated both by histological and biochemical changes and were related with a progress in the colonic oxidative status.

Asian citrus psyllid RNAi pathway - RNAi evidence

USDA-ARS?s Scientific Manuscript database

In silico analyses of the draft genome of Diaphorina citri, the Asian citrus psyllid, for genes within the Ribonucleic acid interference(RNAi), pathway was successful. The psyllid is the vector of the plant-infecting bacterium, Candidatus Liberibacter asiaticus (CLas), which is linked to citrus gree...

76 FR 23449 - Citrus Canker, Citrus Greening, and Asian Citrus Psyllid; Interstate Movement of Regulated...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-27

... conditions, the articles are treated with methyl bromide and shipped in a container that has been sealed with... of any regulated article, including citrus nursery stock, provided that: The article is treated with methyl bromide in accordance with 7 CFR part 305. That part contains our phytosanitary treatment...

Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement.

PubMed

Omar, Ahmad A; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W

2016-01-01

The genus Citrus contains numerous fresh and processed fruit cultivars that are economically important worldwide. New cultivars are needed to battle industry threatening diseases and to create new marketing opportunities. Citrus improvement by conventional methods alone has many limitations that can be overcome by applications of emerging biotechnologies, generally requiring cell to plant regeneration. Many citrus genotypes are amenable to somatic embryogenesis, which became a key regeneration pathway in many experimental approaches to cultivar improvement. This chapter provides a brief history of plant somatic embryogenesis with focus on citrus, followed by a discussion of proven applications in biotechnology-facilitated citrus improvement techniques, such as somatic hybridization, somatic cybridization, genetic transformation, and the exploitation of somaclonal variation. Finally, two important new protocols that feature plant regeneration via somatic embryogenesis are provided: protoplast transformation and Agrobacterium-mediated transformation of embryogenic cell suspension cultures.

Orchard establishment, precocity, and eco-physiological traits of several pomegranate cultivars

USDA-ARS?s Scientific Manuscript database

California faces many threats to food security, ranging from water limitations resulting from long-term drought to invasive pests and disease. Major tree crops, such as citrus and avocado, are threatened by Citrus Greening and Fusarium Dieback, respectively, posing significant economic threats to gr...

Genome-wide genetic variation and comparison of fruit-associated traits between kumquat (Citrus japonica) and Clementine mandarin (Citrus clementina).

PubMed

Liu, Tian-Jia; Li, Yong-Ping; Zhou, Jing-Jing; Hu, Chun-Gen; Zhang, Jin-Zhi

2018-03-01

The comprehensive genetic variation of two citrus species were analyzed at genome and transcriptome level. A total of 1090 differentially expressed genes were found during fruit development by RNA-sequencing. Fruit size (fruit equatorial diameter) and weight (fresh weight) are the two most important components determining yield and consumer acceptability for many horticultural crops. However, little is known about the genetic control of these traits. Here, we performed whole-genome resequencing to reveal the comprehensive genetic variation of the fruit development between kumquat (Citrus japonica) and Clementine mandarin (Citrus clementina). In total, 5,865,235 single-nucleotide polymorphisms (SNPs) and 414,447 insertions/deletions (InDels) were identified in the two citrus species. Based on integrative analysis of genome and transcriptome of fruit, 640,801 SNPs and 20,733 InDels were identified. The features, genomic distribution, functional effect, and other characteristics of these genetic variations were explored. RNA-sequencing identified 1090 differentially expressed genes (DEGs) during fruit development of kumquat and Clementine mandarin. Gene Ontology revealed that these genes were involved in various molecular functional and biological processes. In addition, the genetic variation of 939 DEGs and 74 multiple fruit development pathway genes from previous reports were also identified. A global survey identified 24,237 specific alternative splicing events in the two citrus species and showed that intron retention is the most prevalent pattern of alternative splicing. These genome variation data provide a foundation for further exploration of citrus diversity and gene-phenotype relationships and for future research on molecular breeding to improve kumquat, Clementine mandarin and related species.

Forward vs. backwards selection for seed orchards and cooperative second-generation breeding in the US Pacific Northwest.

Treesearch

R. Johnson; K. Jayawickrama

2003-01-01

Gain from various orchard strategies were modeled. The scenario tested 2,000 first-generation open-pollinated families, from which orchards of 20 selections were formed, using either parents, progeny or both. This was followed by a second-generation breeding population in which 200 full-sib families were tested followed by a second-generation orchard of 20 selections....

Metalized polyethylene mulch to repel Asian citrus psyllid, slow spread of huanglongbing and improve growth of new citrus plantings.

PubMed

Croxton, Scott D; Stansly, Philip A

2014-02-01

Greening or huanglongbing (HLB) is a debilitating disease of citrus caused by Candidatus Liberibactor asiaticus and transmitted by the Asian citrus psyllid (ACP), Diaphorina citri. HLB now occurs worldwide in all major citrus growing regions except the Mediterranean and Australia. Management relies principally on insecticidal control of the ACP vector, but is insufficient, even for young trees which are most susceptible to the disease. We tested the ability of metalized polyethylene mulch to repel adult ACP as well as effects on incidence of HLB and early tree growth. Metalized mulch significantly reduced ACP populations and HLB incidence compared to whiteface mulch or bare ground. In addition, metalized mulch, together with the associated drip irrigation and fertigation system, increased soil moisture, reduced weed pressure, and increased tree growth rate. Metalized mulch slows spread of ACP and therefore HLB pressure on young citrus trees. Metalized mulch can thereby augment current control measures for young trees based primarily on systemic insecticides. Additional costs could be compensated for by increased tree growth rate which would shorten time to crop profitability. These advantages make a compelling case for large-scale trials using metalized mulch in young citrus plantings threatened by HLB. © 2013 Society of Chemical Industry.

Citrus fruit recognition using color image analysis

NASA Astrophysics Data System (ADS)

Xu, Huirong; Ying, Yibin

2004-10-01

An algorithm for the automatic recognition of citrus fruit on the tree was developed. Citrus fruits have different color with leaves and branches portions. Fifty-three color images with natural citrus-grove scenes were digitized and analyzed for red, green, and blue (RGB) color content. The color characteristics of target surfaces (fruits, leaves, or branches) were extracted using the range of interest (ROI) tool. Several types of contrast color indices were designed and tested. In this study, the fruit image was enhanced using the (R-B) contrast color index because results show that the fruit have the highest color difference among the objects in the image. A dynamic threshold function was derived from this color model and used to distinguish citrus fruit from background. The results show that the algorithm worked well under frontlighting or backlighting condition. However, there are misclassifications when the fruit or the background is under a brighter sunlight.

Family indices for seed-orchard selection

Treesearch

Gene Namkoong

1966-01-01

Many seed orchard programs include a stage at which clones or seedlings are culled on the basis of progeny tests. Though breeding systems which involve progeny testing differ in efficiency, they all provide information on an individual's breeding value through its own performance and that of parental or seedling relatives. A combined index on any one trait, using...

Comparative analysis of juice volatiles in selected mandarins, mandarin relatives and other citrus genotypes.

PubMed

Yu, Yuan; Bai, Jinhe; Chen, Chunxian; Plotto, Anne; Baldwin, Elizabeth A; Gmitter, Frederick G

2018-02-01

Citrus fruit flavor is an important attribute prioritized in variety improvement. The present study compared juice volatiles compositions from 13 selected citrus genotypes, including six mandarins (Citrus reticulata), three sour oranges (Citrus aurantium), one blood orange (Citrus sinensis), one lime (Citrus limonia), one Clementine (Citrus clementina) and one satsuma (Citrus unshiu). Large differences were observed with respect to volatile compositions among the citrus genotypes. 'Goutou' sour orange contained the greatest number of volatile compounds and the largest volatile production level. 'Ponkan' mandarin had the smallest number of volatiles and 'Owari' satsuma yielded the lowest volatile production level. 'Goutou' sour orange and 'Moro' blood orange were clearly distinguished from other citrus genotypes based on the analysis of volatile compositions, even though they were assigned into one single group with two other sour oranges by the molecular marker profiles. The clustering analysis based on the aroma volatile compositions was able to differentiate mandarin varieties and natural sub-groups, and was also supported by the molecular marker study. The gas chromatography-mass spectrometry analysis of citrus juice aroma volatiles can be used as a tool to distinguish citrus genotypes and assist in the assessment of future citrus breeding programs. The aroma volatile profiles of the different citrus genotypes and inter-relationships detected among volatile compounds and among citrus genotypes will provide fundamental information on the development of marker-assisted selection in citrus breeding. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

An assessment of DDT and other chlorinated compounds and the reproductive success of American robins (Turdus migratonrius) breeding in fruit orchards.

PubMed

Gill, Harpreet; Wilson, Laurie K; Cheng, Kimberly M; Elliott, John E

2003-01-01

Although DDT was banned in the 1970s, American robins (Turdus migratorius) breeding in fruit orchards of the Okanagan Valley, British Columbia, continue to be contaminated with DDT and its metabolites. The objectives of our study were (1) to assess organochlorine (OC) contamination in robins breeding in Okanagan orchards (1993-1995, 1997-1998) and (2) to determine if exposure affected reproductive success when compared to robins from non-orchard habitat (lower mainland, British Columbia). Robins in orchards had total DDT egg residues of 48.64 mg/kg (geometric mean; n = 92) while those in non-orchard habitat had 1.10 mg/kg (geometric mean; n = 26), wet weight. The probability of nest survival during the incubation period was 96.7% (confidence interval: 95.7-97.5%; n = 165) in orchard habitat and 96.7% (confidence interval: 94.6-98.1%; n = 28) in non-orchard habitat. During the nestling period the probability of nest survival was 98.2% (confidence interval: 97.2-98.9%; n = 123) in orchard habitat and 96.2% (confidence interval: 92.8-98.0%; n = 34) in non-orchard habitat. Clutch (p < 0.0001) and brood size (p = 0.0133) were larger in orchards (n = 150 and n = 93, respectively) compared to non-orchard nests (n = 42 and n = 23, respectively) with no difference in fledge rate. DDE (r2 = 0.11, p = 0.0030, n = 68) and dieldrin (r2 = 0.29, p < 0.0001, n = 68) were negatively correlated with fledge rate in robin eggs collected from orchard habitat, however, low r2 values signify minimal biological significance. Although American robins nesting in Okanagan orchards are exposed to high OC levels, reproductive success does not appear to be negatively impacted.

Spectral difference analysis and airborne imaging classification for citrus greening infected trees

USDA-ARS?s Scientific Manuscript database

Citrus greening, also called Huanglongbing (HLB), became a devastating disease spread through citrus groves in Florida, since it was first found in 2005. Multispectral (MS) and hyperspectral (HS) airborne images of citrus groves in Florida were acquired to detect citrus greening infected trees in 20...

7 CFR 457.106 - Texas citrus tree crop insurance provisions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 6 2014-01-01 2014-01-01 false Texas citrus tree crop insurance provisions. 457.106... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.106 Texas citrus tree crop insurance provisions. The Texas Citrus Tree Crop Insurance Provisions for the 2011 and...

7 CFR 457.106 - Texas citrus tree crop insurance provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 6 2013-01-01 2013-01-01 false Texas citrus tree crop insurance provisions. 457.106... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.106 Texas citrus tree crop insurance provisions. The Texas Citrus Tree Crop Insurance Provisions for the 2011 and...

7 CFR 457.119 - Texas citrus fruit crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 6 2012-01-01 2012-01-01 false Texas citrus fruit crop insurance provisions. 457.119... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.119 Texas citrus fruit crop insurance provisions. The Texas citrus fruit crop insurance provisions for the 2000 and...

7 CFR 457.106 - Texas citrus tree crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 6 2012-01-01 2012-01-01 false Texas citrus tree crop insurance provisions. 457.106... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.106 Texas citrus tree crop insurance provisions. The Texas Citrus Tree Crop Insurance Provisions for the 2011 and...

7 CFR 457.119 - Texas citrus fruit crop insurance provisions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Texas citrus fruit crop insurance provisions. 457.119... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.119 Texas citrus fruit crop insurance provisions. The Texas citrus fruit crop insurance provisions for the 2000 and...

7 CFR 457.106 - Texas citrus tree crop insurance provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 6 2011-01-01 2011-01-01 false Texas citrus tree crop insurance provisions. 457.106... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.106 Texas citrus tree crop insurance provisions. The Texas Citrus Tree Crop Insurance Provisions for the 2011 and...

7 CFR 457.119 - Texas citrus fruit crop insurance provisions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 6 2014-01-01 2014-01-01 false Texas citrus fruit crop insurance provisions. 457.119... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.119 Texas citrus fruit crop insurance provisions. The Texas citrus fruit crop insurance provisions for the 2000 and...

7 CFR 457.119 - Texas citrus fruit crop insurance provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 6 2013-01-01 2013-01-01 false Texas citrus fruit crop insurance provisions. 457.119... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.119 Texas citrus fruit crop insurance provisions. The Texas citrus fruit crop insurance provisions for the 2000 and...

7 CFR 457.119 - Texas citrus fruit crop insurance provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 6 2011-01-01 2011-01-01 false Texas citrus fruit crop insurance provisions. 457.119... INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.119 Texas citrus fruit crop insurance provisions. The Texas citrus fruit crop insurance provisions for the 2000 and...

Long term field evaluation reveals HLB resistance in Citrus relatives

USDA-ARS?s Scientific Manuscript database

Citrus huanglongbing (HLB) is a destructive disease with no known cure. To identify sources of HLB resistance in the subfamily Aurantioideae to which citrus belongs, we conducted a six-year field trial under natural disease challenge conditions in an HLB endemic region. The study included 65 Citrus ...

7 CFR 93.5 - Fees for citrus product analyses set by cooperative agreement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Fees for citrus product analyses set by cooperative... Citrus Products § 93.5 Fees for citrus product analyses set by cooperative agreement. The fees for the analyses of fresh citrus juices and other citrus products shall be set by mutual agreement between the...

Metabolomic analysis of primary metabolites in citrus leaf during defense responses.

PubMed

Asai, Tomonori; Matsukawa, Tetsuya; Kajiyama, Shin'ichiro

2017-03-01

Mechanical damage is one of the unavoidable environmental stresses to plant growth and development. Plants induce a variety of reactions which defend against natural enemies and/or heal the wounded sites. Jasmonic acid (JA) and salicylic acid (SA), defense-related plant hormones, are well known to be involved in induction of defense reactions and play important roles as signal molecules. However, defense related metabolites are so numerous and diverse that roles of individual compounds are still to be elucidated. In this report, we carried out a comprehensive analysis of metabolic changes during wound response in citrus plants which are one of the most commercially important fruit tree families. Changes in amino acid, sugar, and organic acid profiles in leaves were surveyed after wounding, JA and SA treatments using gas chromatography-mass spectrometry (GC/MS) in seven citrus species, Citrus sinensis, Citrus limon, Citrus paradisi, Citrus unshiu, Citrus kinokuni, Citrus grandis, and Citrus hassaku. GC/MS data were applied to multivariate analyses including hierarchical cluster analysis (HCA), primary component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA) to extract stress-related compounds. HCA showed the amino acid cluster including phenylalanine and tryptophan, suggesting that amino acids in this cluster are concertedly regulated during responses against treatments. OPLS-DA exhibited that tryptophan was accumulated after wounding and JA treatments in all species tested, while serine was down regulated. Our results suggest that tryptophan and serine are common biomarker candidates in citrus plants for wound stress. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Metabolic interplay between the Asian citrus psyllid and its Profftella symbiont: An Achilles’ heel of the citrus greening insect vector

USDA-ARS?s Scientific Manuscript database

‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including ‘Candidatus Profftella armatura’, are likely to impact tra...

Molecular analysis of citrus rust (Phyllocoptruta oleivora) populations in Texas

USDA-ARS?s Scientific Manuscript database

Phyllocoptruta olevoria (Acari: Eriophyidae) or the citrus rust mite (CRM) is one of the most economically important mite pests of citrus worldwide. CRM originated from Asia, however it is found in most citrus producing areas, such as, Brazil, Morocco and the United States. Though CRM is a major pes...

Wavelength and polarization affect phototaxis of the Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid, D. citri, is a primary pest for citrus production due to its status as a vector of the citrus disease, huanglongbing. We investigated phototactic behavior of D. citri to evaluate effects of light of specific wavelength or polarization using a horizontal bioassay arena. Wave...

7 CFR 319.56-59 - Fresh citrus fruit from Uruguay.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Fresh citrus fruit from Uruguay. Sweet oranges (Citrus sinensis (L.) Osbeck), lemons (C. limon (L.) Burm... in accordance with labeled instructions, and waxed. (g) Treatment. (1) Citrus fruit other than lemons... of this chapter for A. fraterculus and C. capitata. (2)(i) Lemons may be shipped without a treatment...

Current Situation of Citrus Huanglongbing in Guangdong, P. R. China

USDA-ARS?s Scientific Manuscript database

Guangdong Province is an important citrus production region in China. Citrus Huanglongbing (HLB, yellow shoot disease) was observed in Guangdong probably in the late 1800’s and the disease was first studied there. Since the 1990’s, citrus production in Guangdong has gradually shifted from the coasta...

Development of loop-mediated isothermal amplification and SYBR green real-time PCR methods for the detection of Citrus yellow mosaic badnavirus in citrus species.

PubMed

Anthony Johnson, A M; Dasgupta, I; Sai Gopal, D V R

2014-07-01

Citrus yellow mosaic badnavirus (CMBV) is an important pathogen in southern India spread by infected citrus propagules. One of the measures to arrest the spread of CMBV is to develop methods to screen and certify citrus propagules as CMBV-free. The methods loop-mediated isothermal amplification (LAMP) and SYBR green real-time PCR (SGRTPCR) have been developed for the efficient detection of CMBV in citrus propagules. This paper compares the sensitivities of LAMP and SGRTPCR with polymerase chain reaction (PCR) for the detection of CMBV. Whereas PCR and LAMP were able to detect CMBV from a minimum of 10 ng of total DNA of infected leaf samples, SGRTPCR could detect the same from 1 ng of total DNA. Using SGRTPCR, the viral titres were estimated to be the highest in rough lemon and lowest in Nagpur Mandarin of the five naturally infected citrus species tested. The results will help in designing suitable strategies for the sensitive detection of CMBV from citrus propagules. Copyright © 2014 Elsevier B.V. All rights reserved.

Bird use of organic apple orchards: Frugivory, pest control and implications for production

PubMed Central

Pejchar, Liba; Werner, Scott J.

2017-01-01

As the largest terrestrial biomes, crop and pasturelands can have very large positive or negative impacts on biodiversity and human well-being. Understanding how animals use and impact agroecosystems is important for making informed decisions that achieve conservation and production outcomes. Yet, few studies examine the tradeoffs associated with wildlife in agricultural systems. We examined bird use of organic apple orchards as well as how birds influence fruit production positively through control of an economically important insect pest (codling moth (Cydia pomonella)) and negatively through fruit damage. We conducted transect surveys, observed bird frugivory and assessed bird and insect damage with an exclosure experiment in small organic farms in western Colorado. We found that organic apple orchards in this region provide habitat for a large number of both human-adapted and human-sensitive species and that the species in orchards were relatively similar to adjacent hedgerow habitats. Habitat use did not vary as a function of orchard characteristics, and apple damage by both birds and C. pomonella was consistent within and across apple blocks that varied in size. A small subset of bird species was observed foraging on apples yet the effect of birds as agents of fruit damage appeared rather minor and birds did not reduce C. pomonella damage. Our results demonstrate that organic apple orchards have the potential to provide habitat for diverse bird communities, including species typically sensitive to human activities, with little apparent effect on production. PMID:28910290

Technical Note: Dosimetry of Leipzig and Valencia applicators without the plastic cap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Granero, D., E-mail: dgranero@eresa.com; Candela-Juan, C.; Vijande, J.

2016-05-15

Purpose: High dose rate (HDR) brachytherapy for treatment of small skin lesions using the Leipzig and Valencia applicators is a widely used technique. These applicators are equipped with an attachable plastic cap to be placed during fraction delivery to ensure electronic equilibrium and to prevent secondary electrons from reaching the skin surface. The purpose of this study is to report on the dosimetric impact of the cap being absent during HDR fraction delivery, which has not been explored previously in the literature. Methods: GEANT4 Monte Carlo simulations (version 10.0) have been performed for the Leipzig and Valencia applicators with andmore » without the plastic cap. In order to validate the Monte Carlo simulations, experimental measurements using radiochromic films have been done. Results: Dose absorbed within 1 mm of the skin surface increases by a factor of 1500% for the Leipzig applicators and of 180% for the Valencia applicators. Deeper than 1 mm, the overdosage flattens up to a 10% increase. Conclusions: Differences of treating with or without the plastic cap are significant. Users must check always that the plastic cap is in place before any treatment in order to avoid overdosage of the skin. Prior to skin HDR fraction delivery, the timeout checklist should include verification of the cap placement.« less

Programmable Ultrasonic Sensing System for Targeted Spraying in Orchards

PubMed Central

Stajnko, Denis; Berk, Peter; Lešnik, Mario; Jejčič, Viktor; Lakota, Miran; Štrancar, Andrej; Hočevar, Marko; Rakun, Jurij

2012-01-01

This research demonstrates the basic elements of a prototype automated orchard sprayer which delivers pesticide spray selectively with respect to the characteristics of the targets. The density of an apple tree canopy was detected by PROWAVE 400EP250 ultrasound sensors controlled by a Cypress PSOC CY8C29466 microcontroller. The ultrasound signal was processed with an embedded computer built around a LPC1343 microcontroller and fed in real time to electro-magnetic valves which open/close spraying nozzles in relation to the canopy structure. The analysis focuses on the detection of appropriate thresholds on 15 cm ultrasound bands, which correspond to maximal response to tree density, and this was selected for accurate spraying guidance. Evaluation of the system was performed in an apple orchard by detecting deposits of tartrazine dye (TD) on apple leaves. The employment of programmable microcontrollers and electro-magnetic valves decreased the amount of spray delivered by up to 48.15%. In contrast, the reduction of TD was only up to 37.7% at some positions within the tree crown and 65.1% in the gaps between trees. For all these reasons, this concept of precise orchard spraying can contribute to a reduction of costs and environmental pollution, while obtaining similar or even better leaf deposits. PMID:23202220

[Carbon Source Utilization Characteristics of Soil Microbial Community for Apple Orchard with Interplanting Herbage].

PubMed

Du, Yi-fei; Fang, Kai-kai; Wang, Zhi-kang; Li, Hui-ke; Mao, Peng-juan; Zhang, Xiang-xu; Wang, Jing

2015-11-01

As soil fertility in apple orchard with clean tillage is declined continuously, interplanting herbage in orchard, which is a new orchard management model, plays an important role in improving orchard soil conditions. By using biolog micro-plate technique, this paper studied the functional diversity of soil microbial community under four species of management model in apple orchards, including clear tillage model, interplanting white clover model, interplanting small crown flower model and interplanting cocksfoot model, and the carbon source utilization characteristics of microbial community were explored, which could provide a reference for revealing driving mechanism of ecological process of orchard soil. The results showed that the functional diversity of microbial community had a significant difference among different treatments and in the order of white clover > small crown flower > cocksfoot > clear tillage. The correlation analysis showed that the average well color development (AWCD), Shannon index, Richness index and McIntosh index were all highly significantly positively correlated with soil organic carbon, total nitrogen, microbial biomass carbon, and Shannon index was significantly positively correlated with soil pH. The principal component analysis and the fingerprints of the physiological carbon metabolism of the microbial community demonstrated that grass treatments improved carbon source metabolic ability of soil microbial community, and the soil microbes with perennial legumes (White Clover and small crown flower) had a significantly higher utilization rate in carbohydrates (N-Acetyl-D-Glucosamine, D-Mannitol, β-Methyl-D-Glucoside), amino acids (Glycyl-L-Glutamic acid, L-Serine, L-Threonine) and polymers (Tween 40, Glycogen) than the soil microbes with clear tillage. It was considered that different treatments had the unique microbial community structure and peculiar carbon source utilization characteristics.

Chemical modification of citrus pectin: Structural, physical and rheologial implications.

PubMed

Fracasso, Aline Francielle; Perussello, Camila Augusto; Carpiné, Danielle; Petkowicz, Carmen Lúcia de Oliveira; Haminiuk, Charles Windson Isidoro

2018-04-01

The present study aimed to investigate the physical, structural and rheological modifications caused by the chemical modification process of citrus pectin. Therefore, three commercial citrus pectins with different degree of esterification were chemically modified by sequential alkali and acidic hydrolytic process to produce modified citrus pectins (MCP) with special properties. The molar mass (M w ), degree of esterification (DE), monosaccharide composition, 13 C NMR spectra, homogeneity, morphology (SEM) and rheological behavior of both native and modified citrus pectins (MCP) were investigated. The chemical modification reduced the acid uronic content (up to 28.3%) and molar mass (up to 29.98%), however, showed little influence on the degree of esterification of native pectins. Modified citrus pectins presented higher amounts of neutral monosaccharides, mainly galactose, arabinose and rhamnose, typical of the Ramnogalacturonana-I (RG-I) region. Rheological tests indicated that the native and modified citrus pectins presented pseudoplastic behavior, however, the MCP samples were less viscous, compared to the native ones. Modified samples presented better dissolution in water and less strong gels, with good stability during oscillatory shearing at 25°C. This study aims to better understand the implications that chemical modifications may impose on the structure of citrus pectins. Copyright © 2017 Elsevier B.V. All rights reserved.

Operational forecasting of daily temperatures in the Valencia Region. Part II: minimum temperatures in winter.

NASA Astrophysics Data System (ADS)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of minimum temperatures during winter is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, winter minimum temperatures are considered a parameter of interest and concern since persistent cold-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict cold-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that low temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily minimum temperatures during winter over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the winter forecast period from 1 December 2007 - 31 March 2008. The results obtained are encouraging and indicate a good agreement between the observed and simulated minimum temperatures. Moreover, the model captures quite well the temperatures in the extreme cold episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia

Operational forecasting of daily temperatures in the Valencia Region. Part I: maximum temperatures in summer.

NASA Astrophysics Data System (ADS)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of summer maximum temperatures is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, summer maximum daily temperatures are considered a parameter of interest and concern since persistent heat-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict heat-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily maximum temperatures during summer over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the summer forecast period of 1 June - 30 September, 2007. The results obtained are encouraging and indicate a good agreement between the observed and simulated maximum temperatures. Moreover, the model captures quite well the temperatures in the extreme heat episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia, Spain).

PAMPs, PRRs, effectors and R-genes associated with citrus-pathogen interactions.

PubMed

Dalio, Ronaldo J D; Magalhães, Diogo M; Rodrigues, Carolina M; Arena, Gabriella D; Oliveira, Tiago S; Souza-Neto, Reinaldo R; Picchi, Simone C; Martins, Paula M M; Santos, Paulo J C; Maximo, Heros J; Pacheco, Inaiara S; De Souza, Alessandra A; Machado, Marcos A

2017-03-01

Recent application of molecular-based technologies has considerably advanced our understanding of complex processes in plant-pathogen interactions and their key components such as PAMPs, PRRs, effectors and R-genes. To develop novel control strategies for disease prevention in citrus, it is essential to expand and consolidate our knowledge of the molecular interaction of citrus plants with their pathogens. This review provides an overview of our understanding of citrus plant immunity, focusing on the molecular mechanisms involved in the interactions with viruses, bacteria, fungi, oomycetes and vectors related to the following diseases: tristeza, psorosis, citrus variegated chlorosis, citrus canker, huanglongbing, brown spot, post-bloom, anthracnose, gummosis and citrus root rot. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Identification and characterization of Citrus yellow vein clearing virus, a putative new member of the genus Mandarivirus infecting Citrus spp.

USDA-ARS?s Scientific Manuscript database

Yellow vein clearing virus, an uncharacterized filamentous virus, was first observed in Pakistan in 1988 and later in India in 1997 in Etrog citron (Citrus medica). Based on electron microscopic evidence of filamentous particles, the virus, provisionally named Citrus yellow vein clearing virus (CYVC...

Challenges of managing disease in tall orchard trees – pecan scab, a case study

USDA-ARS?s Scientific Manuscript database

Managing disease in tall orchard trees presents unique issues not found in relatively shorter horticultural and agronomic crops, simply due to height. Pecan scab (caused by Fusicladium effusum [G. Winter] Seyran et al.) is used as an example of a major disease of one of the tallest orchard crops in ...

Transforming Schools through Expanded Learning Time: Orchard Gardens K-8 Pilot School. Update 2013

ERIC Educational Resources Information Center

Chan, Roy

2013-01-01

For years, Orchard Gardens K-8 Pilot School was plagued by low student achievement and high staff turnover. Then, in 2010, with an expanded school schedule made possible through federal funding, Orchard Gardens began a remarkable turnaround. Today, the school is demonstrating how increased learning time, combined with other key turnaround…

Studies of Microbiota Dynamics Reveals Association of "Candidatus Liberibacter Asiaticus" Infection with Citrus (Citrus sinensis) Decline in South of Iran.

PubMed

Passera, Alessandro; Alizadeh, Hamidreza; Azadvar, Mehdi; Quaglino, Fabio; Alizadeh, Asma; Casati, Paola; Bianco, Piero A

2018-06-20

Citrus Decline Disease was recently reported to affect several citrus species in Iran when grafted on a local rootstock variety, Bakraee. Preliminary studies found “ Candidatus Phytoplasma aurantifoliae” and “ Candidatus Liberibacter asiaticus” as putative etiological agents, but were not ultimately able to determine which one, or if an association of both, were causing the disease. The current study has the aim of characterizing the microbiota of citrus plants that are either asymptomatic, showing early symptoms, or showing late symptoms through amplification of the V1⁻V3 region of 16S rRNA gene using an Illumina sequencer in order to (i) clarify the etiology of the disease, and (ii) describe the microbiota associated to different symptom stages. Our results suggest that liberibacter may be the main pathogen causing Citrus Decline Disease, but cannot rule out the possibility of phytoplasma being involved as well. The characterization of microbiota shows that the leaves show only two kinds of communities, either symptomatic or asymptomatic, while roots show clear distinction between early and late symptoms. These results could lead to the identification of bacteria that are related to successful plant defense response and, therefore, to immunity to the Citrus Decline Disease.

The Valencia trough and the origin of the western Mediterranean basins

NASA Astrophysics Data System (ADS)

Vegas, R.

1992-03-01

Evolutionary models for the Valencia trough must be necessarily related to the Neogene-Present geodynamics of the western Mediterranean basins. All these basins occupy new space created in the wake of the westward translation of the Alboran block and the counter-clockwise rotation of the Corso-Sardinian block. This escape-tectonics, microplate dispersal, model can account for the co-existence and progressive migration of compressional and extensional strain fields within the Africa-Europe broad zone of convergence. In this escape-tectonics model, the Valencia trough has resulted in a complex evolution which includes: (1) latest Oligocene-Early Miocene rifting along the Catalan-Valencian margin due to the opening of the Gulf of Lions; (2) almost simultaneous, Early Miocene, transpressive thrusting in the Balearic margin related to the initiation of displacement of the Alboran block; and (3) Late Miocene generalized extension as a consequence of the opening of the South Balearic basin.

Chemical and biological comparison of the fruit extracts of Citrus wilsonii Tanaka and Citrus medica L.

PubMed

Zhao, Pan; Duan, Li; Guo, Long; Dou, Li-Li; Dong, Xin; Zhou, Ping; Li, Ping; Liu, E-Hu

2015-04-15

Citri Fructus (CF), the mature fruit of Citrus wilsonii Tanaka (CWT) or Citrus medica L. (CML), is an important citrus by-product with health promoting and nutritive properties. The present study compares the chemical and biological differences of CWT and CML. Thin layer chromatography and high performance liquid chromatography, coupled with quadrupole time-of-flight tandem mass spectrometry techniques, were employed to compare the chemical profiles of CWT and CML. A total of 25 compounds were identified and the results indicated that there were significant differences in chemical composition between the two CF species. The quantitative results obtained by HPLC coupled with diode array detector method demonstrated that naringin was present in the highest amounts in CWT, whilst nomilin was the most dominant constituent in CML. It was also found that CWT had significantly higher free radical-scavenging activity than CML. Copyright © 2014 Elsevier Ltd. All rights reserved.

Annotation of the Asian citrus psyllid genome reveals a reduced innate immune system

USDA-ARS?s Scientific Manuscript database

Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuway...

Winter-injury following horticultural treatments to overcome juvenility in citrus seedlings

USDA-ARS?s Scientific Manuscript database

Citrus seedling juvenility delays new hybrid evaluation, slows cultivar release, and slows introgression of new traits. A horticultural program reported to overcome citrus juvenility was tested at the Whitmore Citrus Research Foundation farm (Lake County), using replicated Hirado Buntan x Clementine...

23. WILEY CITY LINE CONGDON ORCHARD PACKING HOUSE AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. WILEY CITY LINE - CONGDON ORCHARD PACKING HOUSE AND SPUR, LOOKING NORTHWEST - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

24. WILEY CITY LINE WEST SWITCH TO CONGDON ORCHARD ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. WILEY CITY LINE - WEST SWITCH TO CONGDON ORCHARD PACKING HOUSE SPUR - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

Precocious flowering of juvenile citrus induced by a viral vector based on Citrus leaf blotch virus: a new tool for genetics and breeding.

PubMed

Velázquez, Karelia; Agüero, Jesús; Vives, María C; Aleza, Pablo; Pina, José A; Moreno, Pedro; Navarro, Luis; Guerri, José

2016-10-01

The long juvenile period of citrus trees (often more than 6 years) has hindered genetic improvement by traditional breeding methods and genetic studies. In this work, we have developed a biotechnology tool to promote transition from the vegetative to the reproductive phase in juvenile citrus plants by expression of the Arabidopsis thaliana or citrus FLOWERING LOCUS T (FT) genes using a Citrus leaf blotch virus-based vector (clbvINpr-AtFT and clbvINpr-CiFT, respectively). Citrus plants of different genotypes graft inoculated with either of these vectors started flowering within 4-6 months, with no alteration of the plant architecture, leaf, flower or fruit morphology in comparison with noninoculated adult plants. The vector did not integrate in or recombine with the plant genome nor was it pollen or vector transmissible, albeit seed transmission at low rate was detected. The clbvINpr-AtFT is very stable, and flowering was observed over a period of at least 5 years. Precocious flowering of juvenile citrus plants after vector infection provides a helpful and safe tool to dramatically speed up genetic studies and breeding programmes. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Comparison of Hydrolyzed Protein Baits and Various Grape Juice Products as Attractants for Anastrepha Fruit Flies (Diptera: Tephritidae).

PubMed

Herrera, F; Miranda, E; Gómez, E; Presa-Parra, E; Lasa, R

2016-02-01

Mexican fruit flies, Anastrepha ludens (Loew; Diptera: Tephritidae), have traditionally been trapped in citrus orchards in Mexico using protein hydrolysates as bait. Recently, CeraTrap(®), an enzymatic hydrolyzed protein, has emerged as an effective lure for monitoring A. ludens at the orchard level and is currently being used by growers in the region of Veracruz. Several studies have revealed that grape juice is highly attractive to A. ludens, and recent work supports its potential use for regulation purposes. In our study, the attraction of A. ludens to different grape products was evaluated in citrus orchards and in comparison to other Anastrepha species in an area composed of mango and chicozapote orchards. Attraction to grape lures was compared with CeraTrap and the standard protein Captor +borax trap. In general, CeraTrap was more attractive than different commercial grape products in several experiments. Only Jumex, a commercial grape juice, did not differ significantly from CeraTrap in the capture of A. ludens males and females in a citrus crop. However, several drawbacks were detected when using Jumex grape juice: 1) higher tendency to capture males, 2) less selectivity against non-targeted insects, 3) higher capture of beneficial lacewings, and iv) the need to re-bait weekly owing to lower stability. In the area containing mango and chicozapote, CeraTrap was more attractive than Captor + borax for Anastrepha obliqua and Anastrepha serpentina, followed by grape juice products, which were the least attractive for these fruit fly species. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Risk assessment of various insecticides used for management of Asian citrus psyllid, Diaphorina citri in Florida citrus, against honey bee, Apis mellifera.

PubMed

Chen, Xue Dong; Gill, Torrence A; Pelz-Stelinski, Kirsten S; Stelinski, Lukasz L

2017-04-01

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a major pest of citrus trees worldwide. A wide variety of insecticides are used to manage D. citri populations within citrus groves in Florida. However, in areas shared by citrus growers and beekeepers the use of insecticides may increase the risks of Apis mellifera  L. (Hymenoptera: Apidae) loss and contaminated honey. The objective of this research was to determine the environmental toxicity of insecticides, spanning five different modes of action used to control D. citri, to A. mellifera. The insecticides investigated were imidacloprid, fenpropathrin, dimethoate, spinetoram and diflubenzuron. In laboratory experiments, LD 50 values were determined and ranged from 0.10 to 0.53 ng/μl for imidacloprid, fenpropathrin, dimethoate and spinetoram. LD 50 values for diflubenzuron were >1000 ng/μl. Also, a hazard quotient was determined and ranged from 1130.43 to 10893.27 for imidacloprid, fenpropathrin, dimethoate, and spinetoram. This quotient was <0.447 for diflubenzuron. In field experiments, residual activity of fenpropathrin and dimethoate applied to citrus caused significant mortality of A. mellifera 3 and 7 days after application. Spinetoram and imidacloprid were moderately toxic to A. mellifera at the recommended rates for D. citri. Diflubenzuron was not toxic to A. mellifera in the field as compared with untreated control plots. Phenoloxidase (PO) activity of A. mellifera was higher than in untreated controls when A. mellifera were exposed to 14 days old residues. The results indicate that diflubenzuron may be safe to apply in citrus when A. mellifera are foraging, while most insecticides used for management of D. citri in citrus are likely hazardous under various exposure scenarios.

Mitigating citrus huanglongbing via effective application of antimicrobial compounds and thermotherapy

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB) is a serious citrus disease that threatens the citrus industry worldwide. HLB is a systemic, infectious disease and the putative causal bacterium Candidatus Liberibacter asiaticus (Las) resides in citrus phloem. In this study, the effects of heat treatment, chemical formulations,...

On the stability of the relationship between reference evapotranspiration and single tree transpiration: test and validation over several irrigated tree orchards

NASA Astrophysics Data System (ADS)

Ayyoub, Abdellatif; Er-Raki, Salah; Khabba, Saïd; Merlin, Olivier; César Rodriguez, Julio; Ezzahar, Jamal; Bahlaoui, Ahmed; Chehbouni, Abdelghani

2016-04-01

The present work aims to develop a simple approach relating normalized daily sap flow (per unit of leaf area) and daily ET0 (mm/day) calculated by two methods: FAO-Penman-Monteith (FAO-PM) and Hargreaves-Samani (HARG). The data sets used for developing this approach are taken from three experimental sites (olive trees, cv. "Oleaeuropaea L.", olive trees, cv. "Arbequino" and citrus trees cv. "Clementine Afourar") conducted in the Tensift region around Marrakech, Morocco and one experimental site (pecan orchard, cv. "Caryaillinoinensis, Wangenh. K. Koch") conducted in the Yaqui Valley, northwest of Mexico). The results showed that the normalized daily sap flow (volume of transpired water per unit of leaf area) was linearly correlated with ET0 (mm per day) calculated by FAO-PM method. The coefficient of determination (R2) and the slope of this linear regression varied between 0.71 and 0.97 and between 0.30 and 0.35, respectively, depending on the type of orchards. For HARG method, the relationship between both terms is also linear but with less accuracy (R2 =0.7) as expected due to the underestimation of ET0 by this method. Afterward, the validation of the developed linear relationship was performed over an olive orchard ("Oleaeuropaea L.") where the measurements of sap flow were available for another (2004) cropping season. The scatter plot between the normalized measured and estimated sap flow based on FAO-PM method reveals a very good agreement (slope = 1, with R2 = 0.83 and RMSE=0.14 L/m2 leaf area). However, for the estimation of normalized sap flow based on HARG method, the correlation is more scattered with some underestimation (5%). A further validation wasperformed using the measurements of evapotranspiration (ET) by eddy correlation system and the results showed that the correlation between normalized measured ET and estimated normalized sap flow is best when using FAO-PM method (RMSE=0.33 L/m2 leaf area) for estimating ET0 than when using HARG method (RMSE

Site Plan & Site Section of Citrus Landscape (Showing Relationship ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Site Plan & Site Section of Citrus Landscape (Showing Relationship of Groves & Irrigation System to Grove Canal) - Arlington Heights Citrus Landscape, Southwestern portion of city of Riverside, Riverside, Riverside County, CA

Citrus fruits intake and oral cancer risk: a systematic review and meta-analysis.

PubMed

Cirmi, Santa; Navarra, Michele; Woodside, Jayne V; Cantwell, Marie M

2018-05-10

To quantify the relationship between Citrus intake and risk of cancer of the oral cavity and pharynx. Systematic review and meta-analysis. Ovid MEDLINE, EMBASE, and Web of Science were searched until September 2017. Search terms included Citrus, Citrus aurantifolia, Citrus sinensis, Citrus paradisi, Citrus fruits, Citrus fruits extract, Citrus oil, fruits, oral cancer, mouth cancer, mouth neoplasm. The selection of studies and the systematic review were carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A pre-defined inclusion checklist resulted in the inclusion of articles which were (i) published in peer-reviewed scientific journals; (ii) English language; (iii) and included a measure of Citrus fruit intake and risk of oral and pharyngeal cancer. Studies were excluded if (i) preparations derived from other fruits were used, (ii) Citrus intake was combined with intake of other fruits; (iii) in vitro or animal models were used. We also excluded reviews, systematic reviews, meta-analyses, letters, personal opinions, conference abstracts and book chapters. Three reviewers independently performed the extraction of data from studies included. Seventeen studies met our inclusion criteria and were included in the final review. Pooled analyses showed that those with the highest Citrus fruit intake compared to the lowest intake had a 50% reduction in risk of oral cavity and pharyngeal cancer (OR 0.50; 95% CI 0.43-0.59). The studies included in this review and meta-analysis showed an inverse association between Citrus fruit intake and oral cancer. Copyright © 2018. Published by Elsevier Ltd.

Estimating Cone and Seed Production and Monitoring Pest Damage in Southern Pine Seed Orchards

Treesearch

Carl W. Fatzinger; H. David Muse; Thomas Miller; Helen T. Bhattacharyya

1988-01-01

Field sampling procedures and computer programs are described for monitoring seed production and pest damage in southern pine seed orchards. The system estimates total orchard yields of female strobili and seeds, quantifies pest damage, determines times of year when losses occur, and produces life tables for female strobili. An example is included to illustrate the...

21. WILEY CITY LINE TYPICAL RIGHTOFWAY THROUGH CONGDON ORCHARD ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. WILEY CITY LINE - TYPICAL RIGHT-OF-WAY THROUGH CONGDON ORCHARD PROPERTY, LOOKING WEST - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

Climate-driven spatial mismatches between British orchards and their pollinators: increased risks of pollination deficits

PubMed Central

Polce, Chiara; Garratt, Michael P; Termansen, Mette; Ramirez-Villegas, Julian; Challinor, Andrew J; Lappage, Martin G; Boatman, Nigel D; Crowe, Andrew; Endalew, Ayenew Melese; Potts, Simon G; Somerwill, Kate E; Biesmeijer, Jacobus C

2014-01-01

Understanding how climate change can affect crop-pollinator systems helps predict potential geographical mismatches between a crop and its pollinators, and therefore identify areas vulnerable to loss of pollination services. We examined the distribution of orchard species (apples, pears, plums and other top fruits) and their pollinators in Great Britain, for present and future climatic conditions projected for 2050 under the SRES A1B Emissions Scenario. We used a relative index of pollinator availability as a proxy for pollination service. At present, there is a large spatial overlap between orchards and their pollinators, but predictions for 2050 revealed that the most suitable areas for orchards corresponded to low pollinator availability. However, we found that pollinator availability may persist in areas currently used for fruit production, which are predicted to provide suboptimal environmental suitability for orchard species in the future. Our results may be used to identify mitigation options to safeguard orchard production against the risk of pollination failure in Great Britain over the next 50 years; for instance, choosing fruit tree varieties that are adapted to future climatic conditions, or boosting wild pollinators through improving landscape resources. Our approach can be readily applied to other regions and crop systems, and expanded to include different climatic scenarios. PMID:24638986

Ontogenic variation in citrus flush shoots and its relation with host plant finding and acceptance by Asian citrus psyllid (Hemiptera: Psyllidae)

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae) is a destructive insect mainly because it vectors the bacterial pathogens that cause the deadly and incurable citrus greening disease. Diaphorina citri adult females lay eggs and immature development occurs exclusively on new flush sh...

Changes in anthocyanin production during domestication of citrus

USDA-ARS?s Scientific Manuscript database

Mandarin (C. reticulata), citron (C. medica) and pummelo (C. maxima) are imortant fruit species of the genus Citrus and parents of the interspecific hybrids that constitute the most familiar commercial varities of citrus: sweet orange, sour orange, clementine, lemon lme and grapefruit. Citron and it...

Citrus fruit quality assessment; producer and consumer perspectives

USDA-ARS?s Scientific Manuscript database

Consumption of citrus fruit and juices is popular with consumers worldwide and makes an important contribution to a healthy diet. Nevertheless, consumer preferences for citrus have undergone significant changes over the last twenty years and it is important to understand what consumers are looking ...

Monitoring stink bugs (Hemiptera: Pentatomidae) in mid-Atlantic apple and peach orchards.

PubMed

Leskey, T C; Hogmire, H W

2005-02-01

Pyramid traps coated with "industrial safety yellow" exterior latex gloss enamel paint and baited with Euschistus spp. aggregation pheromone, methyl (2E,4Z)-decadienoate captured more stink bugs than all other baited and unbaited trap types in both apple and peach orchards in 2002 and 2003. Commercial sources of dispensers of methyl (2E,4Z)-decadienoate deployed in association with pyramid traps had a significant impact on trap captures. Captures in pyramid traps were four-fold greater when baited with lures from IPM Technologies, Inc. (Portland, OR) than with lures from Suterra (Bend, OR). Variation in yellow pyramid trap color ("industrial safety yellow" and "standard coroplast yellow") and material (plywood, plastic, and masonite) did not affect trap captures. Brown stink bug was the predominant species captured (58%), followed by dusky stink bug, Euschistus tristigmus (Say) (20%); green stink bug, Acrosternum hilare (Say) (14%); and other stink bugs (Brochymena spp. and unidentified nymphs) (8%). Captures in baited pyramid traps were significantly correlated with tree beating samples in both managed and unmanaged apple orchards and with sweep netting samples in the unmanaged apple orchard. However, problems associated with trapping mechanisms of pyramid trap jar tops and jar traps likely resulted in reduced captures in baited traps. Improved trapping mechanisms must be established to develop an effective monitoring tool for stink bugs in mid-Atlantic orchards.

The Effect of Nest Box Distribution on Sustainable Propagation of Osmia lignaria (Hymenoptera: Megachilidae) in Commercial Tart Cherry Orchards

PubMed Central

Pitts-Singer, T. L.

2017-01-01

The blue orchard bee, Osmia lignaria (Say), is a solitary bee that is an excellent pollinator of tree fruit orchards. Due to the annual rising costs of honey bee hive rentals, many orchardists are eager to develop management tools and practices to support O. lignaria as an alternative pollinator. Establishing O. lignaria pollination as a sustainable industry requires careful consideration of both bee and orchard management. Here, we test the effect of artificial nest box distribution on in-orchard propagation of O. lignaria in Utah commercial tart cherry orchards. Two nest box distributions were compared across three paired, 1.2-ha plots. One distribution, traditionally employed by O. lignaria consultants, included a centrally located tote for mass-nesting with smaller, surrounding ‘satellite’ nest boxes at orchard margins. The other distribution was composed of smaller, more equally distributed nest boxes throughout the 1.2-ha plots. Significantly higher propagation of O. lignaria was observed in the latter nest box distribution, although all treatments resulted in bee return exceeding the number of bees initially released. These findings provide support for the use of O. lignaria in tart cherry orchards, and demonstrate how simple changes to bee set-up and management can influence propagation efforts. PMID:28365763

Wrong postural hygiene and ergonomics in dental students of the University of Valencia (Spain) (part I).

PubMed

Cervera-Espert, J; Pascual-Moscardó, A; Camps-Alemany, I

2018-02-01

Failure to adopt a correct working posture can lead to occupational diseases. Evaluate knowledge in relation to ergonomics about BHOP concept and its application to routine clinical practice amongst undergraduate and postgraduate dental students in the University of Valencia (Valencia, Spain). A study based on interviews of undergraduate and postgraduate dental students in the University of Valencia (Valencia, Spain) was carried out. The information from a total of 336 interviews was used for the statistical analysis, differentiating according to gender and academic year: knowledge of ergonomics, pain prevalence and antecedents, assessment of the possible necessity for improved training in ergonomics, and evaluation of postural hygiene. Only 28.6% of the students were found to sit correctly in the dentist chair. Furthermore, in the opinion of the students, very few subjects during the career afforded adequate teaching in relation to ergonomics and working posture. The analysis of postural hygiene showed great variability. There were no significant differences in posture between males and females, although some incorrect postures appeared to be associated with the academic year (P<.05). However, no significant improvements in postural hygiene were noted on progressing from one academic year to the next. The students in our study were not familiar with the principles of ergonomics and did not sit correctly in the dentist chair. Improved training in this field is required in dental school. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Development of consumer-friendly transgenic citrus plants with potential broad spectrum resistance to HLB, Citrus canker, Phytopthora and other exotic diseases

USDA-ARS?s Scientific Manuscript database

The second year of this CRB funded project has started, which is focused on the development of citrus cultivars that exhibit disease resistance to multiple pathogens such as HLB, Phytophthora and citrus canker diseases. We are using precise genetic engineering to introduce into disease susceptible ...

Management of Citrus Canker in Argentina, a Success Story.

PubMed

Canteros, B I; Gochez, A M; Moschini, R C

2017-10-01

Citrus canker is an important bacterial disease of citrus in several regions of the world. Strains of Xanthomonas citri type-A (Xc-A) group are the primary pathogen where citrus canker occurs. After Xc-A entered the Northeast of Argentina in 1974, the disease spread rapidly from 1977 to 1980 and then slowed down and remained moving at slow pace until 1990 when it became endemic. Citrus canker was detected in Northwest Argentina in 2002. This paper presents the main steps in the fight of the disease and the management strategies that have been used to control citrus canker at this time. We think the process might be usefull to other countries with the same situation. Results from more than 40 years of research in Northeast (NE) Argentina indicate that we are at the limit of favorable environment for the disease. The severity of citrus canker is greatly affected by the environment and El Niño Southern Oscillation (ENSO) phenomenon which causes cyclic fluctuations on the disease intensity in the NE region. Weather-based logistic regression models adjusted to quantify disease levels in field conditions showed that the environmental effect was strongly modulated by the distance from a windbreak. Production of healthy fruits in citrus canker endemic areas is possible knowing the dynamics of the disease. A voluntary Integrated Plan to Reduce the Risk of Canker has been in place since 1994 and it allows growers to export unsymptomatic, uninfested fresh fruit to countries which are free of the disease and require healthy, pathogen free fruits. The experience from Argentina can be replicated in other countries after appropriate trials.

Management of Citrus Canker in Argentina, a Success Story

PubMed Central

Canteros, B. I.; Gochez, A. M.; Moschini, R. C.

2017-01-01

Citrus canker is an important bacterial disease of citrus in several regions of the world. Strains of Xanthomonas citri type-A (Xc-A) group are the primary pathogen where citrus canker occurs. After Xc-A entered the Northeast of Argentina in 1974, the disease spread rapidly from 1977 to 1980 and then slowed down and remained moving at slow pace until 1990 when it became endemic. Citrus canker was detected in Northwest Argentina in 2002. This paper presents the main steps in the fight of the disease and the management strategies that have been used to control citrus canker at this time. We think the process might be usefull to other countries with the same situation. Results from more than 40 years of research in Northeast (NE) Argentina indicate that we are at the limit of favorable environment for the disease. The severity of citrus canker is greatly affected by the environment and El Niño Southern Oscillation (ENSO) phenomenon which causes cyclic fluctuations on the disease intensity in the NE region. Weather-based logistic regression models adjusted to quantify disease levels in field conditions showed that the environmental effect was strongly modulated by the distance from a windbreak. Production of healthy fruits in citrus canker endemic areas is possible knowing the dynamics of the disease. A voluntary Integrated Plan to Reduce the Risk of Canker has been in place since 1994 and it allows growers to export unsymptomatic, uninfested fresh fruit to countries which are free of the disease and require healthy, pathogen free fruits. The experience from Argentina can be replicated in other countries after appropriate trials. PMID:29018307

Variability of arginine content and yield components in Valencia peanut germplasm.

PubMed

Aninbon, Chorkaew; Jogloy, Sanun; Vorasoot, Nimitr; Nuchadomrong, Suporn; Holbrook, C Corley; Kvien, Craig; Puppala, Naveen; Patanothai, Aran

2017-06-01

Peanut seeds are rich in arginine, an amino acid that has several positive effects on human health. Establishing the genetic variability of arginine content in peanut will be useful for breeding programs that have high arginine as one of their goals. The objective of this study was to evaluate the variation of arginine content, pods/plant, seeds/pod, seed weight, and yield in Valencia peanut germplasm. One hundred and thirty peanut genotypes were grown under field condition for two years. A randomized complete block design with three replications was used for this study. Arginine content was analyzed in peanut seeds at harvest using spectrophotometry. Yield and yield components were recorded for each genotype. Significant differences in arginine content and yield components were found in the tested Valencia peanut germplasm. Arginine content ranged from 8.68-23.35 μg/g seed. Kremena was the best overall genotype of high arginine content, number of pods/plant, 100 seed weight and pod yield.

First report of citrus leaf blotch virus in lemon in China

USDA-ARS?s Scientific Manuscript database

Citrus leaf blotch virus (CLBV) is a species of genus Citrivirus in the family Betaflexiviridae. The virus infects several species of the genus Citrus spp., but has not been previously reported from Lemon [Citrus limon (L.)]. The virus was identified in a lemon tree displaying yellow vein clearing i...

The draft genome of sweet orange (Citrus sinensis).

PubMed

Xu, Qiang; Chen, Ling-Ling; Ruan, Xiaoan; Chen, Dijun; Zhu, Andan; Chen, Chunli; Bertrand, Denis; Jiao, Wen-Biao; Hao, Bao-Hai; Lyon, Matthew P; Chen, Jiongjiong; Gao, Song; Xing, Feng; Lan, Hong; Chang, Ji-Wei; Ge, Xianhong; Lei, Yang; Hu, Qun; Miao, Yin; Wang, Lun; Xiao, Shixin; Biswas, Manosh Kumar; Zeng, Wenfang; Guo, Fei; Cao, Hongbo; Yang, Xiaoming; Xu, Xi-Wen; Cheng, Yun-Jiang; Xu, Juan; Liu, Ji-Hong; Luo, Oscar Junhong; Tang, Zhonghui; Guo, Wen-Wu; Kuang, Hanhui; Zhang, Hong-Yu; Roose, Mikeal L; Nagarajan, Niranjan; Deng, Xiu-Xin; Ruan, Yijun

2013-01-01

Oranges are an important nutritional source for human health and have immense economic value. Here we present a comprehensive analysis of the draft genome of sweet orange (Citrus sinensis). The assembled sequence covers 87.3% of the estimated orange genome, which is relatively compact, as 20% is composed of repetitive elements. We predicted 29,445 protein-coding genes, half of which are in the heterozygous state. With additional sequencing of two more citrus species and comparative analyses of seven citrus genomes, we present evidence to suggest that sweet orange originated from a backcross hybrid between pummelo and mandarin. Focused analysis on genes involved in vitamin C metabolism showed that GalUR, encoding the rate-limiting enzyme of the galacturonate pathway, is significantly upregulated in orange fruit, and the recent expansion of this gene family may provide a genomic basis. This draft genome represents a valuable resource for understanding and improving many important citrus traits in the future.

Valencia College, No. 1 Nationwide: It's All about "Student Experience"

ERIC Educational Resources Information Center

Adam, Michelle

2012-01-01

Twelve years ago, Sanford Shugart took the helm at Valencia College. This school of 70,000-plus students in Orlando, FL, seemed like any other community college, but Shugart's reason for being there, and the change this college was about to undergo, was anything but ordinary. Before his arrival, the school had begun a process called Campus…

Preinfection of citrus by RB strains of Citrus tristeza virus (CTV) negatively affected expression of a modified T36 CTV vector

USDA-ARS?s Scientific Manuscript database

Genetically modified T36 Citrus tristeza virus (T36-mCTV) is showing promise in Florida to mitigate huanglongbing (HLB) by expressing antimicrobial peptides and RNAi against the presumed pathogen, “Candidatus Liberibacter asiaticus” (CLas), and its vector, the Asian citrus psyllid (ACP). To this end...

Consumer preferences for fresh citrus: Impacts of demographic and behavioral characteristics

USDA-ARS?s Scientific Manuscript database

From 2000 to 2006, per capita consumption of fresh citrus fruit increased by 11.0%, but the relative shares of types of citrus consumed changed. Per capita consumption of the historically dominant citrus fruit, fresh oranges, experienced a continuous decline from 12.4 pounds to 7.4 pounds from 1990 ...

A phagostimulant blend for the Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

Chemical cues that condition orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of great interest because it is the primary vector of the causal pathogen of citrus greening disease. Previous work in our lab identified a blend of formic and acetic acids as s...

An RNA-Seq-based reference transcriptome for Citrus.

PubMed

Terol, Javier; Tadeo, Francisco; Ventimilla, Daniel; Talon, Manuel

2016-03-01

Previous RNA-Seq studies in citrus have been focused on physiological processes relevant to fruit quality and productivity of the major species, especially sweet orange. Less attention has been paid to vegetative or reproductive tissues, while most Citrus species have never been analysed. In this work, we characterized the transcriptome of vegetative and reproductive tissues from 12 Citrus species from all main phylogenetic groups. Our aims were to acquire a complete view of the citrus transcriptome landscape, to improve previous functional annotations and to obtain genetic markers associated with genes of agronomic interest. 28 samples were used for RNA-Seq analysis, obtained from 12 Citrus species: C. medica, C. aurantifolia, C. limon, C. bergamia, C. clementina, C. deliciosa, C. reshni, C. maxima, C. paradisi, C. aurantium, C. sinensis and Poncirus trifoliata. Four different organs were analysed: root, phloem, leaf and flower. A total of 3421 million Illumina reads were produced and mapped against the reference C. clementina genome sequence. Transcript discovery pipeline revealed 3326 new genes, the number of genes with alternative splicing was increased to 19,739, and a total of 73,797 transcripts were identified. Differential expression studies between the four tissues showed that gene expression is overall related to the physiological function of the specific organs above any other variable. Variants discovery analysis revealed the presence of indels and SNPs in genes associated with fruit quality and productivity. Pivotal pathways in citrus such as those of flavonoids, flavonols, ethylene and auxin were also analysed in detail. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Tree fruit orchard of the future: An overview

USDA-ARS?s Scientific Manuscript database

Mechanization has been prevailing in row crops over the past decades, and now gradually in some fruit crops, with integration of innovative computers, robotics, mechanics, and precision orchard management. This talk will give an overview of challenges facing commercial fruit industries and needs of ...

Expected genetic gains and development plans for two longlead pine third-generation seedling seed orchards

Treesearch

C.D. Nelson; L.H. Lott; D.P. Gwaze

2005-01-01

Selection and thinning plans were developed for two longleaf pine (Pinus palushis Mill .), third-generation seedling seed orchards located in southeastern Mississippi and central Louisiana. The two orchards were part of several long-term experimental field tests designed to investigate genetic variation in height growth and brown spot needle blight (...

Diurnal patterns of chlorophyll fluorescence and CO2 fixation in orchard grown Torreya taxifolia (Arn.).

Treesearch

Anita C. Koehn; Robert L. Doudrick

1999-01-01

Diurnal patterns of chlorophyll fluorescence and CO2 fixation in orchard measurements were taken on sunny days in October 1996, on three Torreya taxifolia (Arn.) plants grown in an open canopy orchard. Information from chlorophyll fluorescence quenching analysis indicated that during periods of highest light intensity and temperatures there were...

Comparative carotenoid compositions during maturation and their antioxidative capacities of three citrus varieties.

PubMed

Yoo, Kyung-Mi; Moon, BoKyung

2016-04-01

This study investigated total carotenoid content, comparative carotenoid composition, vitamin C content, and total antioxidant capacity of three citrus varieties which are Yuza (Citrus junos Sieb ex Tabaka), Kjool (Citrus unshiu Marcow), and Dangyooja (Citrus grandis Osbeck). Seven carotenoids were identified, with β-cryptoxanthin, astaxanthin, and zeaxanthin being predominant in citrus varieties. Ripening increased the total carotenoid in three citrus varieties. Individual carotenoid of canthaxanthin, astaxanthin, and α-carotene in citrus varieties decreased with maturation, whereas the others increased with ripening. Yuza exhibited the highest total antioxidant capacity in 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays, with VCEAC values of 582.9 mg/100 g and 451.5 mg/100g, respectively. The relative VCEAC values were vitamin C (1.00)>lycopene (0.375), α-carotene (0.304), β-carotene (0.289), β-cryptoxanthin (0.242), and zeaxanthin (0.099). These results indicate that Yuza contains higher amounts of total carotenoids, individual carotenoids, and vitamin C than other Korean citrus varieties. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Guide to Energy Savings - For the Orchard Grower.

ERIC Educational Resources Information Center

Wynn, N. A.

This booklet gives a brief overview of energy use in orchard crop production, and gives examples of cutting costs of fertilization, irrigation, weed management, pest management, high density crops, frost protection, and equipment use. (BB)

Citrus alongside the sinking wreckage of MV Pacific Star in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Citrus alongside the sinking wreckage of MV Pacific Star in the Pacific Ocean. Pacific Star's captain used his vessel to ram the cutter after he was ordered to stop and submit to inspection by a boarding team. Citrus was not seriously damaged in the collision. U.S. Coast Guard personnel recovered a large amount of marijuana from the wreckage - U.S. Coast Guard Cutter CITRUS, Coos Bay, Coos County, OR

Interaction between endophytic bacteria from citrus plants and the phytopathogenic bacteria Xylella fastidiosa, causal agent of citrus-variegated chlorosis.

PubMed

Lacava, P T; Araújo, W L; Marcon, J; Maccheroni, W; Azevedo, J L

2004-01-01

To isolate endophytic bacteria and Xylella fastidiosa and also to evaluate whether the bacterial endophyte community contributes to citrus-variegated chlorosis (CVC) status in sweet orange (Citrus sinensis [L.] Osbeck cv. Pera). The presence of Xylella fastidiosa and the population diversity of culturable endophytic bacteria in the leaves and branches of healthy, CVC-asymptomatic and CVC-symptomatic sweet orange plants and in tangerine (Citrus reticulata cv. Blanco) plants were assessed, and the in vitro interaction between endophytic bacteria and X. fastidiosa was investigated. There were significant differences in endophyte incidence between leaves and branches, and among healthy, CVC-asymptomatic and CVC-symptomatic plants. Bacteria identified as belonging to the genus Methylobacterium were isolated only from branches, mainly from those sampled from healthy and diseased plants, from which were also isolated X. fastidiosa. The in vitro interaction experiments indicated that the growth of X. fastidiosa was stimulated by endophytic Methylobacterium extorquens and inhibited by endophytic Curtobacterium flaccumfaciens. This work provides the first evidence of an interaction between citrus endophytic bacteria and X. fastidiosa and suggests a promising approach that can be used to better understand CVC disease.

7 CFR 319.56-41 - Citrus from Peru.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Citrus from Peru. 319.56-41 Section 319.56-41... from Peru. Grapefruit (Citrus paradisi), limes (C. aurantiifolia), mandarins or tangerines (C... States from Peru under the following conditions: (a) The fruit must be accompanied by a permit issued in...

7 CFR 319.56-41 - Citrus from Peru.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 5 2011-01-01 2011-01-01 false Citrus from Peru. 319.56-41 Section 319.56-41... from Peru. Grapefruit (Citrus paradisi), limes (C. aurantiifolia), mandarins or tangerines (C... States from Peru under the following conditions: (a) The fruit must be accompanied by a permit issued in...

What's the latest on USDA citrus scion breeding?

USDA-ARS?s Scientific Manuscript database

In its 120 year history, the USDA citrus scion breeding program has provided the mainstays of the Florida specialty citrus industry. In the last few years, the USDA has released US Early Pride mandarin, US Seedless Pineapple sweet orange and most recently, US Furr/US Furr-ST mandarin. Clearly huangl...

Huanglongbing: An overview of a complex pathosystem ravaging the world's citrus.

PubMed

da Graça, John V; Douhan, Greg W; Halbert, Susan E; Keremane, Manjunath L; Lee, Richard F; Vidalakis, Georgios; Zhao, Hongwei

2016-04-01

Citrus huanglongbing (HLB) has become a major disease and limiting factor of production in citrus areas that have become infected. The destruction to the affected citrus industries has resulted in a tremendous increase to support research that in return has resulted in significant information on both applied and basic knowledge concerning this important disease to the global citrus industry. Recent research indicates the relationship between citrus and the causal agent of HLB is shaped by multiple elements, in which host defense responses may also play an important role. This review is intended to provide an overview of the importance of HLB to a wider audience of plant biologists. Recent advances on host-pathogen interactions, population genetics and vectoring of the causal agent are discussed. © 2015 Institute of Botany, Chinese Academy of Sciences.

Impact of biochar on the anaerobic digestion of citrus peel waste.

PubMed

Fagbohungbe, Michael O; Herbert, Ben M J; Hurst, Lois; Li, Hong; Usmani, Shams Q; Semple, Kirk T

2016-09-01

In this study, the impact of different types of biochar and biochar ratios on the anaerobic digestion of citrus peel waste was investigated. Citrus peel has an inhibitory effect on anaerobic digestion. The presence of biochar had two effects: a reduction in the length of the lag phase and greater production of methane relative to citrus peel waste only incubations. The microbial lag phases decreased with increase in citrus peel to biochar ratios, with 2:1 having the longest lag phase of 9.4days and 1:3, the shortest, with the value of 7.5days. The cumulative methane production in incubations containing biochar and citrus peel ranged from 163.9 to 186.8ml CH4 gVS(-1), while citrus peel only produced 165.9ml CH4 gVS(-1). Examination of the biochar material revealed colonies of putative methanogens. The synergy of d-limonene adsorption and microbial immobilization by biochar appears to improve the performance of anaerobic digestion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modification of carotenoid levels by abscission agents and expression of carotenoid biosynthetic genes in 'valencia' sweet orange.

PubMed

Alferez, Fernando; Pozo, Luis V; Rouseff, Russell R; Burns, Jacqueline K

2013-03-27

The effect of 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP) and ethephon on peel color, flavedo carotenoid gene expression, and carotenoid accumulation was investigated in mature 'Valencia' orange ( Citrus sinensis L. Osbeck) fruit flavedo at three maturation stages. Abscission agent application altered peel color. CMNP was more effective than ethephon in promoting green-to-red (a) and blue-to-yellow (b) color at the middle and late maturation stages and total carotenoid changes at all maturation stages. Altered flow of carotenoid precursors during maturation due to abscission agents was suggested by changes in phytoene desaturase (Pds) and ζ-carotene desaturase (Zds) gene expression. However, each abscission agent affected downstream expression differentially. Ethephon application increased β-carotene hydroxilase (β-Chx) transcript accumulation 12-fold as maturation advanced from the early to middle and late stages. CMNP markedly increased β- and ε-lycopene cyclase (Lcy) transcript accumulation 45- and 15-fold, respectively, at midmaturation. Patterns of carotenoid accumulation in flavedo were supported in part by gene expression changes. CMNP caused greater accumulation of total flavedo carotenoids at all maturation stages when compared with ethephon or controls. In general, CMNP treatment increased total red carotenoids more than ethephon or the control but decreased total yellow carotenoids at each maturation stage. In control fruit flavedo, total red carotenoids increased and yellow carotenoids decreased as maturation progressed. Trends in total red carotenoids during maturation were consistent with measured a values. Changes in carotenoid accumulation and expression patterns in flavedo suggest that regulation of carotenoid accumulation is under transcriptional, translational, and post-translational control.

Factors affecting transmission rates of 'Candidatus Liberibacter asiaticus' by Asian citrus psyllid

USDA-ARS?s Scientific Manuscript database

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest because it transmits a bacterium ‘Candidatus Liberibacter asiaticus’ (CLas) responsible for a serious disease of citrus known as Asiatic huanglongbing (citrus greening disease). USDA-ARS researchers recently established a program...

Relationships between nutrient composition of flowers and fruit quality in orange trees grown in calcareous soil.

PubMed

Pestana, Maribela; Beja, Pedro; Correia, Pedro José; de Varennes, Amarilis; Faria, Eugénio Araújo

2005-06-01

To determine if flower nutrient composition can be used to predict fruit quality, a field experiment was conducted over three seasons (1996-1999) in a commercial orange orchard (Citrus sinensis (L.) Osbeck cv. 'Valencia Late', budded on Troyer citrange rootstock) established on a calcareous soil in southern Portugal. Flowers were collected from 20 trees during full bloom in April and their nutrient composition determined, and fruits were harvested the following March and their quality evaluated. Patterns of covariation in flower nutrient concentrations and in fruit quality variables were evaluated by principal component analysis. Regression models relating fruit quality variables to flower nutrient composition were developed by stepwise selection procedures. The predictive power of the regression models was evaluated with an independent data set. Nutrient composition of flowers at full bloom could be used to predict the fruit quality variables fresh fruit mass and maturation index in the following year. Magnesium, Ca and Zn concentrations measured in flowers were related to fruit fresh mass estimations and N, P, Mg and Fe concentrations were related to fruit maturation index. We also established reference values for the nutrient composition of flowers based on measurements made in trees that produced large (> 76 mm in diameter) fruit.

Citrus stand ages regulate the fraction alteration of soil organic carbon under a citrus/Stropharua rugodo-annulata intercropping system in the Three Gorges Reservoir area, China.

PubMed

Zhang, Yang; Ni, Jiupai; Yang, John; Zhang, Tong; Xie, Deti

2017-08-01

Soil carbon fractionation is a valuable indicator in assessing stabilization of soil organic matter and soil quality. However, limited studies have addressed how different vegetation stand ages under intercropping agroforestry systems, could affect organic carbon (OC) accumulation in bulk soil and its physical fractions. A field study thus investigated the impact of citrus plantation age (15-, 25-, and 45-year citrus) on the bulk soil organic carbon (SOC) and SOC fractions and yields of Stropharia rugoso-annulata (SRA) in the Three Gorges Reservoir area, Chongqing, China. Results indicated that the intercropping practice of SRA with citrus significantly increased the SOC by 57.4-61.6% in topsoil (0-10 cm) and by 24.8-39.9% in subsoil (10-30 cm). With a significantly higher enhancement under the 25-year citrus stand than the other two stands, all these citrus stands of three ages also resulted in a significant increase of free particulate OC (fPOC, 60.1-62.4% in topsoil and 34.8-46.7% in subsoil), intra-micro aggregate particulate OC (iPOC, 167.6-206.0% in topsoil and 2.77-61.09% in subsoil), and mineral-associated OC (MOC, 43.6-46.5% in topsoil and 26.0-51.5% in subsoil). However, there were no significant differences in yields of SRA under three citrus stands. Our results demonstrated that citrus stand ages did play an important role in soil carbon sequestration and fractionation under a citrus/SRA intercropping system, which could therefore provide a sustainable agroforestry system to enhance concurrently the SOC accumulation while mitigating farmland CO 2 emission.

Overexpression of a citrus NDR1 ortholog increases disease resistance in Arabidopsis.

PubMed

Lu, Hua; Zhang, Chong; Albrecht, Ute; Shimizu, Rena; Wang, Guanfeng; Bowman, Kim D

2013-01-01

Emerging devastating diseases, such as Huanglongbing (HLB) and citrus canker, have caused tremendous losses to the citrus industry worldwide. Genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. The key to the success of this approach relies on a thorough understanding of defense mechanisms of citrus. Studies of Arabidopsis and other plants have provided a framework for us to better understand defense mechanisms of citrus. Salicylic acid (SA) is a key signaling molecule involved in basal defense and resistance (R) gene-mediated defense against broad-spectrum pathogens. The Arabidopsis gene NDR1 (NON-RACE-SPECIFIC DISEASE RESISTANCE 1) is a positive regulator of SA accumulation and is specifically required for signaling mediated by a subset of R genes upon recognition of their cognate pathogen effectors. Our bioinformatic analysis identified an ortholog of NDR1 from citrus, CsNDR1. Overexpression of CsNDR1 complemented susceptibility conferred by the Arabidopsis ndr1-1 mutant to Pseudomonas syringae strains and also led to enhanced resistance to an oomycete pathogen Hyaloperonospora arabidopsidis. Such heightened resistance is associated with increased SA production and expression of the defense marker gene PATHOGENESIS RELATED 1 (PR1). In addition, we found that expression of PR1 and accumulation of SA were induced to modest levels in citrus infected with Candidatus Liberibacter asiaticus, the bacterial pathogen associated with HLB disease. Thus, our data suggest that CsNDR1 is a functional ortholog of Arabidopsis NDR1. Since Ca. L. asiaticus infection only activates modest levels of defense responses in citrus, we propose that genetically increasing SA/NDR1-mediated pathways could potentially lead to enhanced resistance against HLB, citrus canker, and other destructive diseases challenging global citrus production.

Overexpression of a citrus NDR1 ortholog increases disease resistance in Arabidopsis

PubMed Central

Lu, Hua; Zhang, Chong; Albrecht, Ute; Shimizu, Rena; Wang, Guanfeng; Bowman, Kim D.

2013-01-01

Emerging devastating diseases, such as Huanglongbing (HLB) and citrus canker, have caused tremendous losses to the citrus industry worldwide. Genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. The key to the success of this approach relies on a thorough understanding of defense mechanisms of citrus. Studies of Arabidopsis and other plants have provided a framework for us to better understand defense mechanisms of citrus. Salicylic acid (SA) is a key signaling molecule involved in basal defense and resistance (R) gene-mediated defense against broad-spectrum pathogens. The Arabidopsis gene NDR1 (NON-RACE-SPECIFIC DISEASE RESISTANCE 1) is a positive regulator of SA accumulation and is specifically required for signaling mediated by a subset of R genes upon recognition of their cognate pathogen effectors. Our bioinformatic analysis identified an ortholog of NDR1 from citrus, CsNDR1. Overexpression of CsNDR1 complemented susceptibility conferred by the Arabidopsis ndr1-1 mutant to Pseudomonas syringae strains and also led to enhanced resistance to an oomycete pathogen Hyaloperonospora arabidopsidis. Such heightened resistance is associated with increased SA production and expression of the defense marker gene PATHOGENESIS RELATED 1 (PR1). In addition, we found that expression of PR1 and accumulation of SA were induced to modest levels in citrus infected with Candidatus Liberibacter asiaticus, the bacterial pathogen associated with HLB disease. Thus, our data suggest that CsNDR1 is a functional ortholog of Arabidopsis NDR1. Since Ca. L. asiaticus infection only activates modest levels of defense responses in citrus, we propose that genetically increasing SA/NDR1-mediated pathways could potentially lead to enhanced resistance against HLB, citrus canker, and other destructive diseases challenging global citrus production. PMID:23761797

California's Effort to Improve Almond Orchard Crop Coefficients

NASA Astrophysics Data System (ADS)

Sanden, B. L.; Fulton, A. E.; Munk, D. S.; Ewert, S.; Little, C.; Anderson, F.; Connell, J. H.; Rivera, M.; Orang, M. N.; Snyder, R. L.

2012-04-01

Almonds are a major agricultural commodity in California and optimal irrigation management is important for production, protecting the environment, and long term water resources planning. While evapotranspiration (ET) estimates are widely used for water resource planning, it is used less for "realtime" irrigation management for several reasons. One problem is the lack of confidence in the crop coefficient (Kc) values that are used with reference ET (ETo) to estimate well-watered crop ET (ETc). This is especially true for orchard crops. Until recently, the Kc values used to estimate the ETc of most orchard crops in California were derived using measurements of applied water, runoff, and soil water content depletion with the assumption that the trees were transpiring at a rate that was not restricted by water availability. For decades, a typical midseason Kc value used for clean-cultivated almond orchards was 0.90. Recently, a study was conducted by the University of California and the California Department of Water Resources to improve the Kc estimates for almond orchards; helping growers improve their on-farm water management for better production and less adverse impacts on the environment. Field experiments were conducted in four locations (Butte, Fresno, Kern, and Tehama Counties) spanning 1000 km north to south within the Central Valley of California over somewhat different climates. California Irrigation Management Information System (CIMIS) weather stations were used with the ASCE-EWRI standardized reference evapotranspiration equation for short canopies to determine ETo. Latent heat flux (LE), in all four orchards, was estimated using the residual of the energy balance equation: LE=Rn-G-H from measured net radiation (Rn), ground heat flux (G), and sensible heat flux (H) using surface renewal and eddy covariance measurements. The LE was divided by the latent heat of vaporization (L) to determine ETc. In three years of measurements in Kern County, the data

Orchard factors associated with resistance and cross resistance to sterol demethylation inhibitor fungicides in populations of Venturia inaequalis from Pennsylvania.

PubMed

Pfeufer, Emily E; Ngugi, Henry K

2012-03-01

Orchard management practices, such as destroying of overwintered inoculum and limiting the number of fungicide applications, are often recommended as tactics for slowing the development of resistance to sterol demethylation-inhibitor (DMI) fungicides in populations of Venturia inaequalis. However, there is little quantitative evidence relating the use of such practices to levels of resistance in orchards. The aim of this study was to evaluate the sensitivity of V. inaequalis isolates from Pennsylvania to DMI fungicides, and to identify orchard management factors related to the incidence of resistant isolates. In total, 644 single-spore V. inaequalis cultures obtained from 20 apple orchards in 2008 or 2009 were tested for sensitivity to myclobutanil, fenbuconazole, or difenoconazole. Growers provided management history of the sampled plots. Widespread shifts toward resistance to the three fungicides were noted, with mean effective concentration for 50% inhibition (EC(50)) values of 2.136, 0.786, and 0.187 μg/ml for myclobutanil, fenbuconazole, and difenoconazole, respectively. Cross resistance to the three fungicides was documented in high correlation (Spearman's r > 0.6) between mean EC(50) values for 14 orchards. Based on a 0.5-μg/ml threshold, 66 and 26% of isolates were resistant to myclobutanil and fenbuconazole, respectively, and 22% were cross resistant to the two fungicides. A significant between-year shift toward increased resistance was noted in two of three orchards surveyed in both years. Failure to use dormant copper sprays, older trees, larger orchards, orchards with ≤10 cultivars, and application of >4 DMI sprays were positively correlated (0.0001 < P < 0.05) with the incidence of resistant isolates. Isolates from orchards with >4 DMI sprays were four times as likely to be resistant to fenbuconazole (odds ratio = 4.57; P = 0.015). Isolates from orchards without dormant copper sprays were twice as likely to be cross-shifted toward resistance to all

Overexpression of a citrus NDR1 ortholog increases disease resistance in Arabidopsis

USDA-ARS?s Scientific Manuscript database

Emerging devastating diseases, such as Huanglongbing (HLB) and citrus canker, have caused tremendous losses to the citrus industry worldwide. Genetic engineering is a powerful approach that could allow us to increase citrus resistance against these diseases. The key to the success of this approach r...

Investigation of crop canopy temperature in apple study orchard

NASA Astrophysics Data System (ADS)

Tökei, L.; Dunkel, Z.

2003-04-01

The paper shows a sophisticated case study for the possible determination of transpiration of apple orchard. A 'Scheduler' type water stress instrument originally developed for crops was used in the study apple orchard of the university. The air and crop canopy temperatures, the relative humidity and the radiation were measured. The aim was to determine the influence of these factors at different level of the canopy, with various exposures of the tree crowns. The measurements were made on several trees in certain selected rows and on those planted in concentric rows in a round field. The relationship between crop canopy and sir temperatures appeared to depend primarily on illumination. This can be greatly affected by shading conditions, but air motion cannot be neglected, the effect of which increases when its direction is in agreement with the direction of the rows. Its efficiency also has a significant effect on air humidity conditions. The relative humidity and air temperature values were used to calculate the equivalent temperature, also considering latent heat flux, and finally the evapotranspiration of plantation. From differences in the equivalent and air temperatures, conclusions can be drawn on the intensity and daily course of transpiration. Using this method differences at given level could not be demonstrated in the relatively opera orchards studied. According to the results, transpiration is the strongest in the morning, after which it significantly decreases by the afternoon and becomes more intense again early at night.

Annotation of gene function in citrus using gene expression information and co-expression networks

PubMed Central

2014-01-01

Background The genus Citrus encompasses major cultivated plants such as sweet orange, mandarin, lemon and grapefruit, among the world’s most economically important fruit crops. With increasing volumes of transcriptomics data available for these species, Gene Co-expression Network (GCN) analysis is a viable option for predicting gene function at a genome-wide scale. GCN analysis is based on a “guilt-by-association” principle whereby genes encoding proteins involved in similar and/or related biological processes may exhibit similar expression patterns across diverse sets of experimental conditions. While bioinformatics resources such as GCN analysis are widely available for efficient gene function prediction in model plant species including Arabidopsis, soybean and rice, in citrus these tools are not yet developed. Results We have constructed a comprehensive GCN for citrus inferred from 297 publicly available Affymetrix Genechip Citrus Genome microarray datasets, providing gene co-expression relationships at a genome-wide scale (33,000 transcripts). The comprehensive citrus GCN consists of a global GCN (condition-independent) and four condition-dependent GCNs that survey the sweet orange species only, all citrus fruit tissues, all citrus leaf tissues, or stress-exposed plants. All of these GCNs are clustered using genome-wide, gene-centric (guide) and graph clustering algorithms for flexibility of gene function prediction. For each putative cluster, gene ontology (GO) enrichment and gene expression specificity analyses were performed to enhance gene function, expression and regulation pattern prediction. The guide-gene approach was used to infer novel roles of genes involved in disease susceptibility and vitamin C metabolism, and graph-clustering approaches were used to investigate isoprenoid/phenylpropanoid metabolism in citrus peel, and citric acid catabolism via the GABA shunt in citrus fruit. Conclusions Integration of citrus gene co-expression networks

Processess involved in the dispersal of Xanthomonas citri pv. citri from canker-infected citrus canopies, and in the infection of citrus foliage

USDA-ARS?s Scientific Manuscript database

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida, and epidemics result in yield loss and market penalties both in Florida and elsewhere, where the pathogen occurs and susceptible citrus is cultivated. The bacterium is dispersed in rain splash, and storms with...

Processes involved in the dispersal of Xanthomonas citri pv. citri from canker-infectd citrus canopies, and in the infection of citrus foliage

USDA-ARS?s Scientific Manuscript database

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida, and epidemics result in yield loss and market penalties both in Florida, and elsewhere where the pathogen occurs, and susceptible citrus is cultivated. The bacterium is dispersed in rain splash, and storms wit...

Weed suppression by grasses for orchard floor management

USDA-ARS?s Scientific Manuscript database

Fruit trees in orchards of the mid-Atlantic region are often planted in vegetation-free rows alternating with grass travel alleys. The tree rows can be maintained vegetation-free by herbicides or tillage but soil degradation or tree injury can result from these practices. Grasses that suppress wee...

Orchard Display Nursery evaluation summary (2005-2006)

Treesearch

Derek J. Tilley; Loren St. John

2006-01-01

The Orchard Display Nursery was planted on November 16, 2004 in cooperation with the Great Basin Native Plant Selection and Increase Project. The nursery includes 82 accessions of 27 native and introduced grass, forb and shrub species. Each accession was planted in 7 X 60 foot plots. See Tilley et al (2005) for descriptions of the species and accessions planted. The...

Weaver ant role in cashew orchards in Vietnam.

PubMed

Peng, Renkang; Lan, La Pham; Christian, Keith

2014-08-01

Cashew (Anacardium occidentale L.) is a very important source of income for more than 200,000 farmer households in Vietnam. The present cashew productivity in Vietnam is low and unstable, and pest damage is partly responsible for this. Cashew farmers rely on pesticides to minimize the damage, resulting in adverse impacts on farm environment and farmers' health. Weaver ants (Oecophylla spp) are effective biocontrol agents of a range of cashew insect pests in several cashew-growing countries, and these ants are widely distributed in Vietnam. The aim of this study is to evaluate the potential of weaver ants in cashew orchards in Vietnam. Field surveys and field experiment were conducted in five cashew orchards from July 2006 to January 2008 in Binh Phuoc, Dong Nai, and Ba Ria Vung Tau provinces, Vietnam. Based on the field surveys, the most important pests that damage flushing foliar and floral shoots and young cashew fruits and nuts were mosquito bugs, brown shoot borers, blue shoot borers, and fruit-nut borers. The damage caused by each of these pests was significantly lower on trees with weaver ants compared with trees without the ants, showing that the ants were able to keep these pest damages under the control threshold. Regular monitoring of the field experiment showed that weaver ants were similar to insecticides for controlling mosquito bugs, blue shoot borers, fruit-nut borers, leaf rollers, and leaf miners. Aphids did not become major pests in plot with weaver ants. To manage insect pest assemblage in cashew orchards, an integrated pest management using weaver ants as a major component is discussed.

Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

PubMed

Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

2011-02-01

The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

Converting citrus wastes into value-added products: Economic and environmently friendly approaches.

PubMed

Sharma, Kavita; Mahato, Neelima; Cho, Moo Hwan; Lee, Yong Rok

2017-02-01

Citrus fruits, including oranges, grapefruits, lemons, limes, tangerines, and mandarins, are among the most widely cultivated fruits around the globe. Its production is increasing every year due to rising consumer demand. Citrus-processing industries generate huge amounts of wastes every year, and citrus peel waste alone accounts for almost 50% of the wet fruit mass. Citrus waste is of immense economic value as it contains an abundance of various flavonoids, carotenoids, dietary fiber, sugars, polyphenols, essential oils, and ascorbic acid, as well as considerable amounts of some trace elements. Citrus waste also contains high levels of sugars suitable for fermentation for bioethanol production. However, compounds such as D-limonene must be removed for efficient bioethanol production. The aim of the present article was to review the latest advances in various popular methods of extraction for obtaining value-added products from citrus waste/byproducts and their potential utility as a source of various functional compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

21 CFR 74.302 - Citrus Red No. 2.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color additive...

21 CFR 74.302 - Citrus Red No. 2.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color additive...

21 CFR 74.302 - Citrus Red No. 2.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color additive...

21 CFR 74.302 - Citrus Red No. 2.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color additive...

21 CFR 74.302 - Citrus Red No. 2.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Citrus Red No. 2. 74.302 Section 74.302 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Foods § 74.302 Citrus Red No. 2. (a) Identity. (1) The color additive...

Inhibitory effect of Epstein-Barr virus activation by Citrus fruits, a cancer chemopreventor.

PubMed

Iwase, Y; Takemura, Y; Ju-ichi, M; Kawaii, S; Yano, M; Okuda, Y; Mukainaka, T; Tsuruta, A; Okuda, M; Takayasu, J; Tokuda, H; Nishino, H

1999-05-24

To search useful compounds in Citrus fruit for cancer chemoprevention, we carried out a primary screening of extracts of fruit peels and seeds from 78 species of the genus Citrus and those from two Fortunella and one Poncirus species, which were closely related to the genus Citrus. These Citrus extracts inhibited the Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) as a useful screening method for anti-tumor promoters. Our results indicated that Citrus containing substances may be inhibit susceptibility factors involved in the events leading to the development of cancer.

Bidirectional reflectance effects derived from ASAS imagery of a pecan orchard

NASA Astrophysics Data System (ADS)

Staenz, Karl; Gauthier, Robert P.; Teillet, Phil M.; Williams, Daniel J.

1993-09-01

Bidirectional reflectance factors (BRF) for a pecan orchard have been studied using Advanced Solid-State Array Spectrometer (ASAS) data acquired in the solar principal plane at altitudes of 2300 m and 5300 m above ground. In particular, the angular dependency of the BRF of different targets such as sunlit and shaded portions of the pecan tree, orchard floor, and soil (road) have been studied for viewing directions between -45 degrees and +45 degrees. The results indicate in general an increasing reflectance from the forward scattering direction to the backscattering direction. In addition, an increase in pixel size has significant effects on the surface BRFs.

Assessment of contamination from arsenical pesticide use on orchards in the great valley region, Virginia and West Virginia, USA

USGS Publications Warehouse

Robinson, G.R.; Larkin, S.P.; Boughton, C.J.; Reed, B.W.; Sibrell, P.L.

2007-01-01

Lead arsenate pesticides were widely used in apple orchards from 1925 to 1955. Soils from historic orchards in four counties in Virginia and West Virginia contained elevated concentrations of As and Pb, consistent with an arsenical pesticide source. Arsenic concentrations in approximately 50% of the orchard site soils and approximately 1% of reference site soils exceed the USEPA Preliminary Remediation Goal (PRG) screening guideline of 22 mg kg-1 for As in residential soi, defined on the basis of combined chronic exposure risk. Approximately 5% of orchard site soils exceed the USEPA PRG for Pb of 400 mg kg-1 in residential soil; no reference site soils sampled exceed this value. A variety of statistical methods were used to characterize the occurrence, distribution, and dispersion of arsenical pesticide residues in soils, stream sediments, and ground waters relative to landscape features and likely background conditions. Concentrations of Zn, Pb, and Cu were most strongly associated with high developed land density and population density, whereas elevated concentrations of As were weakly correlated with high orchard density, consistent with a pesticide residue source. Arsenic concentrations in ground water wells in the region are generally <0.005 mg L-1. There was no spatial association between As concentrations in ground water and proximity to orchards. Arsenic had limited mobility into ground water from surface soils contaminated with arsenical pesticide residues at concentrations typically found in orchards. ?? ASA, CSSA, SSSA.

The Effect of Nest Box Distribution on Sustainable Propagation of Osmia lignaria (Hymenoptera: Megachilidae) in Commercial Tart Cherry Orchards.

PubMed

Boyle, N K; Pitts-Singer, T L

2017-01-01

The blue orchard bee, Osmia lignaria (Say), is a solitary bee that is an excellent pollinator of tree fruit orchards. Due to the annual rising costs of honey bee hive rentals, many orchardists are eager to develop management tools and practices to support O. lignaria as an alternative pollinator. Establishing O. lignaria pollination as a sustainable industry requires careful consideration of both bee and orchard management. Here, we test the effect of artificial nest box distribution on in-orchard propagation of O. lignaria in Utah commercial tart cherry orchards. Two nest box distributions were compared across three paired, 1.2-ha plots. One distribution, traditionally employed by O. lignaria consultants, included a centrally located tote for mass-nesting with smaller, surrounding 'satellite' nest boxes at orchard margins. The other distribution was composed of smaller, more equally distributed nest boxes throughout the 1.2-ha plots. Significantly higher propagation of O. lignaria was observed in the latter nest box distribution, although all treatments resulted in bee return exceeding the number of bees initially released. These findings provide support for the use of O. lignaria in tart cherry orchards, and demonstrate how simple changes to bee set-up and management can influence propagation efforts. Published by Oxford University Press on behalf of the Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Uptake and Distribution of Soil Applied Zinc by Citrus Trees—Addressing Fertilizer Use Efficiency with 68Zn Labeling

PubMed Central

Hippler, Franz Walter Rieger; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Boaretto, Antonio Enedi; Abreu-Junior, Cassio Hamilton; Mattos, Dirceu

2015-01-01

The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay) that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff) and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays. PMID:25751056

Uptake and distribution of soil applied zinc by citrus trees-addressing fertilizer use efficiency with 68Zn labeling.

PubMed

Hippler, Franz Walter Rieger; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Boaretto, Antonio Enedi; Abreu-Junior, Cassio Hamilton; Mattos, Dirceu

2015-01-01

The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay) that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff) and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays.

Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles’ Heel of the Citrus Greening Insect Vector

PubMed Central

Ramsey, John S.; Johnson, Richard S.; Hoki, Jason S.; Kruse, Angela; Mahoney, Jaclyn; Hilf, Mark E.; Hunter, Wayne B.; Hall, David G.; Schroeder, Frank C.; MacCoss, Michael J.; Cilia, Michelle

2015-01-01

‘Candidatus Liberibacter asiaticus’ (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including ‘Candidatus Profftella armatura’, are likely to impact transmission of CLas. We used quantitative mass spectrometry to compare the proteomes of CLas(+) and CLas(-) populations of D. citri, and found that proteins involved in polyketide biosynthesis by the endosymbiont Profftella were up-regulated in CLas(+) insects. Mass spectrometry analysis of the Profftella polyketide diaphorin in D. citri metabolite extracts revealed the presence of a novel diaphorin-related polyketide and the ratio of these two polyketides was changed in CLas(+) insects. Insect proteins differentially expressed between CLas(+) and CLas(-) D. citri included defense and immunity proteins, proteins involved in energy storage and utilization, and proteins involved in endocytosis, cellular adhesion, and cytoskeletal remodeling which are associated with microbial invasion of host cells. Insight into the metabolic interdependence between the insect vector, its endosymbionts, and the citrus greening pathogen reveals novel opportunities for control of this disease, which is currently having a devastating impact on citrus production worldwide. PMID:26580079

Non-transgenic RNAi technology to control insects on citrus

USDA-ARS?s Scientific Manuscript database

This research demonstrated a non-transgenic delivery method for ribonucleic acid interference, RNAi, that reduced fitness as measured in increased mortality over time, of two insect pests of citrus, ie. psyllids and leafhoppers. The Asian citrus psyllid transmits a deadly plant-infecting bacterium o...

Citrus species and hybrids depicted by near- and mid-infrared spectroscopy.

PubMed

Páscoa, Ricardo Nmj; Moreira, Silvana; Lopes, João A; Sousa, Clara

2018-01-31

Citrus trees are among the most cultivated plants in the world, with a high economic impact. The wide sexual compatibility among relatives gave rise to a large number of hybrids that are difficult to discriminate. This work sought to explore the ability of infrared spectroscopy to discriminate among Citrus species and/or hybrids and to contribute to the elucidation of its relatedness. Adult leaves of 18 distinct Citrus plants were included in this work. Near- and mid-infrared (NIR and FTIR) spectra were acquired from leaves after harvesting and a drying period of 1 month. Spectra were modelled by principal component analysis and partial least squares discriminant analysis. Both techniques revealed a high discrimination potential (78.5-95.9%), being the best results achieved with NIR spectroscopy and air-dried leaves (95.9%). Infrared spectroscopy was able to successfully discriminate several Citrus species and/or hybrids. Our results contributed also to enhance insights regarding the studied Citrus species and/or hybrids. Despite the benefit of including additional samples, the results herein obtained clearly pointed infrared spectroscopy as a reliable technique for Citrus species and/or hybrid discrimination. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Allotetraploid hybrids between citrus and seven related genera produced by somatic hybridization.

PubMed

Grosser, J W; Mourao-Fo, F A; Gmitter, F G; Louzada, E S; Jiang, J; Baergen, K; Quiros, A; Cabasson, C; Schell, J L; Chandler, J L

1996-04-01

We have developed an efficient protoplast-fusion method to produce somatic hybrid allopolyploid plants that combine Citrus with seven related genera, including four that are sexually incompatible. In this paper we report the creation of 18 new allotetraploid hybrids of Citrus, including ten among sexually incompatible related genera, that may have direct cultivar potential as improved citrus rootstocks. All hybrids were confirmed by cytological and RAPD analyses. If fertile, the attributes of these hybrids may be amenable to further genetic manipulation by breeding at the tetraploid level. Wide somatic hybridization of Citrus via protoplast fusion bypasses biological barriers to the natural allopolyploidization of Citrus, and creates new evolutionary opportunities that would be difficult or impossible to achieve by natural or conventional hybridization.

Weed suppression by grasses for orchard floor management

USDA-ARS?s Scientific Manuscript database

Fruit trees in orchards of the mid-Atlantic region of the U.S. are often planted in vegetation-free rows alternating with grass travel alleys. The tree rows can be maintained vegetation-free by herbicides or tillage, but soil degradation or tree injury can result. Grass that is managed to suppress...

Utilizing immunomarking techniques to track Halyomorpha halys (Hemiptera: Pentatomidae) movement and distribution within a peach orchard

PubMed Central

Jones, Vincent P.; Nielsen, Anne L.

2016-01-01

In this study we focus on the invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), which has a strong dispersal capacity and has had a significant impact on several cropping systems, including peach (Prunus persica (L.)). Management of H. halys has relied on intensive insecticide use, and thus a better understanding of its dispersal behavior may assist in developing improved management strategies. In order to investigate H. halys movement and distribution patterns within a peach orchard we applied ecologically safe, food protein markers to the trees along the orchard border (chicken egg albumin in the form of liquid egg whites) and to the trees within the orchard interior (bovine casein in the form of cow’s milk). We used enzyme-linked immunosorbent assays (ELISA) to assess whether collected H. halys were “marked” with either of the two protein markers, revealing where in the orchard the bugs had visited. From the density data we determined that H. halys is a perimeter-driven pest in peaches, with a significantly higher density of bugs collected along the orchard border. Interestingly, this trend is primarily driven by the distribution of male bugs. The protein marking data revealed that a small proportion of male H. halys move equally between the orchard border and interior, while a small proportion of females move predominately to the border after visiting the interior. The verification of a strong edge-effect, although potentially sex-specific, implies that H. halys displays a dispersal behavior that may also be exploited for management, which may help growers more efficiently and more effectively manage H. halys. PMID:27190711

[Prevalence of indirect sharing of drug-injecting paraphernalia in Galicia, Madrid, Seville and Valencia [Spain

PubMed

Bravo, María J; Royuela, Luis; Barrio, Gregorio; Rodríguez-Arenas, María A; de la Fuente, Luis

2004-01-01

To study drug-injecting practices, particularly indirect sharing of injecting paraphernalia (ISIP), and sexual risk behavior. We performed a cross-sectional study of 1638 users of needle exchange programs (NEPs). Different types of ISIP were studied: taking diluted drugs in a syringe used by others, placing the needle in a recipient with other used needles, and reusing cleaning liquid previously used by others. The prevalence of injecting with syringes already used by others was 16% in Galicia, 4.7% in Madrid, 17.6% in Seville and 13.2% in Valencia (p < 0.001). With geographical variations, other types of ISIP (Galicia: 32.4%; Madrid: 28.5%; Seville: 42.6%; Valencia: 27.4% -p < 0.001-) were more frequent than injecting with syringes already used by others (Galicia: 32.4%; Madrid: 28.5%; Seville: 42.6%; Valencia: 27.4% -p < 0.001-). The percentage not injecting with syringes used by others but performing ISIP was 21.7%, 25.3%, 28.2% and 18.1% (p < 0.01) respectively. In all geographical areas, sexual risk practices were more prevalent with steady sex partners (68.6%, 72.0%, 77.8%, 72.8% [NS]) than with casual partners (36.6%, 40.9%, 37.9%, 23.9% [NS]). Among injectors with a stable partner, 81.3% in Galicia, 75.9% in Madrid, 86.1% in Seville and 79.7% in Valencia reported that his/her serological status was negative for HIV or was unknown (p < 0.001). ISIP is more prevalent than injection with syringes already used by others. For a substantial percentage of injectors, ISIP is the only risk practice. ISIP and the low use of condoms, particularly with steady partners, could be a contributory factor to the spread of HIV, hepatitis C virus, and hepatitis B virus infection.

Risk assessment and monitoring programme of nitrates through vegetables in the Region of Valencia (Spain).

PubMed

Quijano, Leyre; Yusà, Vicent; Font, Guillermina; McAllister, Claudia; Torres, Concepción; Pardo, Olga

2017-02-01

This study was carried out to determine current levels of nitrate in vegetables marketed in the Region of Valencia (Spain) and to estimate the toxicological risk associated with their intake. A total of 533 samples of seven vegetable species were studied. Nitrate levels were derived from the Valencia Region monitoring programme carried out from 2009 to 2013 and food consumption levels were taken from the first Valencia Food Consumption Survey, conducted in 2010. The exposure was estimated using a probabilistic approach and two scenarios were assumed for left-censored data: the lower-bound scenario, in which unquantified results (below the limit of quantification) were set to zero and the upper-bound scenario, in which unquantified results were set to the limit of quantification value. The exposure of the Valencia consumers to nitrate through the consumption of vegetable products appears to be relatively low. In the adult population (16-95 years) the P99.9 was 3.13 mg kg -1 body weight day -1 and 3.15 mg kg -1 body weight day -1 in the lower bound and upper bound scenario, respectively. On the other hand, for young people (6-15 years) the P99.9 of the exposure was 4.20 mg kg -1 body weight day -1 and 4.40 mg kg -1 body weight day -1 in the lower bound and upper bound scenario, respectively. The risk characterisation indicates that, under the upper bound scenario, 0.79% of adults and 1.39% of young people can exceed the Acceptable Daily Intake of nitrate. This percentage could join the vegetable extreme consumers (such as vegetarians) of vegetables. Overall, the estimated exposures to nitrate from vegetables are unlikely to result in appreciable health risks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparing SEBAL and METRIC: Evapotranspiration Models Applied to Paramount Farms Almond Orchards

NASA Astrophysics Data System (ADS)

Furey, B. J.; Kefauver, S. C.

2011-12-01

Two evapotranspiration models were applied to almond and pistachio orchards in California. The SEBAL model, developed by W.G.M. Bastiaanssen, was programmed in MatLab for direct comparison to the METRIC model, developed by R.G. Allen and the IDWR. Remote sensing data from the NASA SARP 2011 Airborne Research Program was used in the application of these models. An evaluation of the models showed that they both followed the same pattern in evapotranspiration (ET) rates for different types of ground cover. The models exhibited a slightly different range of values and appeared to be related (non-linearly). The models both underestimated the actual ET at the CIMIS weather station. However, SEBAL overestimated the ET of the almond orchards by 0.16 mm/hr when applying its crop coefficient to the reference ET. This is compared to METRIC, which underestimated the ET of the almond orchards by only 0.10 mm/hr. Other types of ground cover were similarly compared. Temporal variability in ET rates between the morning and afternoon were also observed.

Overview in two parts: Right view showing orchard path on ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Overview in two parts: Right view showing orchard path on left eucalyptus windbreak bordering knoll on right. Camera facing 278" west. - Goerlitz House, 9893 Highland Avenue, Rancho Cucamonga, San Bernardino County, CA

Citric acid compounds of tangerines peel extract (Citrus reticulata) as potential materials teeth whitening

NASA Astrophysics Data System (ADS)

Pratiwi, F.; Tinata, J. K.; Prakasa, A. W.; Istiqomah; Hartini, E.; Isworo, S.

2017-04-01

Peel of citrus fruit (Citrus reticulata) has a variety of possible chemical compounds that may serve as a potential whitening teeth. This research is conducted on a laboratory scale; therefore, it needs to be developed on an application scale. A quasi-experimental was employed in this study. Citric acid extraction was carried out on the type of Sweet Orange (Citrus Aurantium L), Tangerine (Citrus Reticulata Blanco or Citrus Nobilis), Pomelo (Citrus Maxima Merr, Citrus grandis Osbeck), and Lemon (Citrus Limon Linn). Citric acid’s ability test as teeth whitener was performed on premolar teeth with concentrations of 2.5%, 5%, and 10%. The experiments were replicated in 3 times, and teeth whiteness level was measured using Shade Guide VITA Classical. The result of this research showed that citric acid in every kind of orange peel with various concentration has different abilities on whitening teeth. The highest colour level obtained from Tangerine peel’s citric acid concentration of 5%. Orange peel extract has the best teeth whitening abilities tested by the method of Gass Chromatography to know the active ingredients.