Development of alternaria blight in indian mustard genotypes under field conditions

Development of Alternaria blight caused by Alternaria brassicae days after sowing (DAS) in relation to disease resistance components was assessed in nine genotypes of Indian mustard (Brassica juncea) under natural conditions. Two genotypes viz., PR 8988 and PR 9024 exhibited slow blighting and had lowest number of spots, reduced size of spot, least number of conidia/spot and lowest disease index on leaf and pod. The maximum increase in disease development was recorded during 62 DAS to 72 DAS on leaves and from 100 DAS to 110 DAS on pods.