Effect of different nutrient media on radial growth of Alternaria brassicae (Berk.) Sacc. infecting different Brassica host crops

Alternaria brassicae (Berk.) Sacc. is the most common and destructive pathogen of a number of Brassica crops belong to family Brassicaceae. It has been reported from all the continent of the world and causes considerable losses in terms of quality and quantity of crop produce. The present investigation was undertaken in vitro, to know the effect of different nutrient media viz., Potato Dextrose Agar (PDA), V-8 Juice Agar (V8JA), Richard’s Agar (RA), Czapeck’s Dox Agar (CDA) and Corn Meal Agar (CMA) on the growth of A. brassicae isolates collected from the different Brassica host crops i.e. Mustard, Cauliflower, Cabbage and Radish. These isolates were designated on the basis of their hosts as Acae M, Acae Cf, Acae Ca and Acae R, respectively. Radial growth of all isolates was observed after seven days of incubation. The result showed a marked variation in radial growth of A. brassicae isolates. However, maximum growths of all isolates were recorded in V-8 Juice Agar (V8JA) followed by Potato Dextrose Agar (PDA) while the minimum growth of pathogen was observed in Corn Meal Agar (CMA).