Survey, estimation of losses and symptomatology in major cabbage growing areas of Rajasthan by Alternaria leaf spot disease

Abstract

There were distinct variations in symptoms observed in the disease samples collected during Rabi 2012 from the four cabbage growing districts of Rajasthan. Isolates of Alternaria brassicicola recovered from various samples collected from Udaipur, Jaipur, Bundi, and Ajmer. The fungal pathogens were isolated, purified and identified as A. brassicicola and their pathogenicity was confirmed. Fields survey was carried out during Rabi season2012-13 and recorded maximum percent incidence (34.78) and minimum yield (196.2 kg/100m2) and maximum yield loss (34.6%) in Udaipur district. Four isolates showed variations in symptoms on inoculations in pot grown plants and also in growth characteristics, colony diameter, rate of sporulation and the size of conidia.