Automatic recognition of quarantine citrus diseases

Citrus exports to foreign markets are severely limited today by fruit diseases. Some of them, like citrus canker, black spot and scab, are quarantine for the markets. For this reason, it is important to perform strict controls before fruits are exported to avoid the inclusion of citrus affected by them. Nowadays, technical decisions are based on visual diagnosis of human experts, highly dependent on the degree of individual skills. This work presents a model capable of automatic recognize the quarantine diseases. It is based on the combination of a feature selection method and a classifier that has been trained on quarantine illness symptoms. Citrus samples with citrus canker, black spot, scab and other diseases were evaluated. Experimental work was performed on 212 samples of mandarins from a Nova cultivar. The proposed approach achieved a classification rate of quarantine/not-quarantine samples of over 83% for all classes, even when using a small subset (14) of all the available features (90). The results obtained show that the proposed method can be suitable for helping the task of citrus visual diagnosis, in particular, quarantine diseases recognition in fruits.Fil: Stegmayer, Georgina. Universidad Tecnologica Nacional. Facultad Regional Santa Fe. Centro de Investigacion y Desarrollo de Ingenieria en Sistemas de Informacion; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Santa Fe. Instituto de Investigacion en Señales, Sistemas e Inteligencia Computacional; Argentina; ArgentinaFil: Milone, Diego Humberto. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnológico Santa Fe. Instituto de Investigacion en Señales, Sistemas e Inteligencia Computacional; Argentina; ArgentinaFil: Garran, Sergio Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Burdyn, Lourdes. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; Argentin

Characterization of sensitivity of grove and packing house isolates of Penicillium digitatum to pyrimethanil

In most northeast Argentinean citrus packing houses, postharvest fungicide treatments are based onthe use of thiabendazole and imazalil. However, these fungicides have been used in a manner highlyconducive to the selection and proliferation of resistant biotypes of Penicillium digitatum, the main fruitdecay fungus in the area. Recently, a new fungicide, pyrimethanil (PYR), was introduced to control molds.Aims of this study were to determine the baseline sensitivities for PYR against isolates of P. digitatumconsidering its use in the region is not yet widespread and to evaluate the control of the fungus in vivo.One hundred and nine (109) P. digitatum isolates were collected from diseased fruit within citrus groves(43 isolates) and packing houses (66 isolates). EC50was determined for each isolate by measuring colonydiameters on different agar dilutions of the fungicide. The mean EC50value of the green mold isolatescollected from the groves was 0.14 ± 0.03 mg L−1while the mean EC50of those collected from packinghouses was 0.13 ± 0.05 mg L−1. No resistant isolates were found in the field where the fungicide is notused, while one isolate originated from a packing house showed an EC50of 3.40 mg L−1, 26-fold higherthan the mean level. This isolate was collected from lemons stored in cool rooms of a packing house wherePYR had not been used. Fruit decay by sensitive isolates was reduced approximately 80% by PYR appliedat 500–600 mg L−1by immersion for 60 s at room temperature to inoculated oranges and mandarins. Incontrast, the resistant isolate was not controlled by PYR applied at 1000 mg L−1. Thus, the introduction ofPYR applied into packing houses should be done carefully and control strategies should be implementedin order to minimize the development of resistant isolates.EEA ConcordiaFil: Vazquez, Daniel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Panozzo, Marina Graciela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Almiron, Nanci Jacqueline. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Bello, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Burdyn, Lourdes. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Garran, Sergio Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; Argentin

Proteomic, metabalomic, and biochemical analysis of heat treated Valencia oranges during storage

Heat treatment induces defense mechanisms and triggers physiological responses that allow citrus fruit to withstand stressful conditions during storage. The aim of this paper was to identify changes in the proteome and the biochemistry of Valencia oranges (Citrus sinensis cv Valencia late) subjected to heat treatment before 0, 30 and 60 d of storage at 5 °C. Heat treatment for 48 h at 37 °C and 90% relative humidity was followed by 24 h at 20 °C. Differentially expressed proteins were detected by two-dimensional differential gel electrophoresis and identified by matrix-assisted laser desorption/ionization MS. Twenty eight different proteins in 40 spots among the 61 analyzed were identified. Functional classification showed that the main affected categories were “Cell rescue, defense, and virulence” and “Metabolism”; while 20% were found to be storage proteins with the rest related to minor categories. Activity of antioxidant enzymes was also evaluated. The most conspicuous change was an increase in superoxide dismutase in both the flavedo and juice sacs. Peroxidases increased in flavedo but decreased in sacs while alcohol dehydrogenase increased in treated flavedo, but not in sacs. Other fermentative enzymes were not affected. Metabolite content showed a higher concentration of sugars in heat treated fruit, while the main acids were slightly or not affected. These results are consistent with the development of a lower degree of fruit susceptibility to fungal pathogens, thus explaining the maintenance of postharvest quality.EEA ConcordiaFil: Perotti, Valeria Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: del Vecchio, Hernán A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Sansevich, Alina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Meier, Guillermo Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Bello, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Cocco, Mariángeles. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Garran, Sergio Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Anderson, Catalina Margarita. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Vazquez, Daniel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Podesta, Florencio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro de Estudios Fotosintéticos y Bioquímicos (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentin

Cítricos : Xanthomonas axonopodis pv. citri (Hasse) Vaut. (Cancrosis de los cítricos)

A través del uso de análisis serológicos se logró identificar y clasificar distintos tipos de cancrosis, causada por diferentes patovares de la bacteria.EEA Alto ValleFil: Tito, María Josefina. Universidad Nacional de Entre Ríos; ArgentinaFil: Vera, Luis Maria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Messina, Miguel Angel. Proyecto BID-PRODAO-INTAFil: Vazquez, Daniel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Moschini, Ricardo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Recursos Naturales. Instituto de Clima y Agua; ArgentinaFil: Canteros, Blanca Isabel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bella Vista; ArgentinaFil: Garran, Sergio Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Concordia; ArgentinaFil: Martinez, Malvina Irene. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro de Investigaciones en Recursos Naturales. Instituto de Clima y Agua; ArgentinaFil: Kornowski, Marcela Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; ArgentinaFil: Dummel, Delia Marlene. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; ArgentinaFil: Agostini, Juan Pedro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; Argentin