Preliminary disease progress curve of Potyviruses and vector interaction in garlic crop in Argentina

PEROTTO MC; LANATI S; PANONTO S; CAFRUNE EE,; CONCI V. C

Ithaca, New York

Simposio; 11th International Plant Viruses Epidemiology Symposium, 3rd Workshop of the Plant Virus Ecology Network; 2010

ICPVE

. Correlation between total number of vectors and potyviruses incidence, were Garlic is vegetatively propagated, resulting in widespread infection by viruses. All the materials currently in use have varying levels of virus infection, which affect their development and limit productivity. Plants are mainly infected by Potyviruses. Onion yellow dwarf virus (OYDV) and Leek yellow stripe virus (LYSV) have been detected worldwide. These are the most important viruses in terms of the damage, with garlic bulb weight reduced between 24 and 60% for OYDV and between 17 and 54% for LYSV. It is clearly important for the control of these pathogens to obtain virus-free material, and to have programs to produce certified virus-free stocks of popular garlic cultivars. At field, the virus-free material is natural infected by vectors. The present studied aimed to evaluate the epidemiology of Potyviruses in virus free plants exposed at normal conditions. Potyviruses epidemics were monitored in the main garlic growing area. OYDV and LYSV incidence were evaluated during a crop cycle, determined with nitrocellulose-enzyme-linked immunosorbent assay (NC-ELISA). Temporal analysis of epidemics was compared with monomolecular, logistic, Gompertz and exponential models for goodness of fit. Of all the models, Exponential model described well the epidemics, R²=0.97 for OYDV and R²=0.90 for LYSV. Area under the disease progress curve was higher for LYSV 687.64 than OYDV 372.23. Aphid activity was assessed with water traps (Moerike type). Weekly estimation was performed to determinate number and specie. There were 22 different species with a range 403 to 2high and consistent (0.95, p‹0.000035 for OYDV and 0.85, p‹0.00174 for LYSV).