Management of Alternaria blight in Indian mustard through fungicides under field conditions

Five fungitoxicants viz., mancozeb (0.2%), azoxystrobin (0.05%), propiconazole (0.05%), difenconazole (0.05%) and hexaconazole (0.05%) were tested for their efficacy against Alternaria blight disease alone as single spray at 45 DAS and in combination with mancozeb at 45 DAS followed by spray of other four fungicides individually at 60 DAS under field conditions for two consecutive years during rabi 2015-16 and 2016-17. The spray of different fungitoxicants alone as single spray treatment or each fungicide in succession with mancozeb (0.2%) significantly reduced the Alternaria blight disease over control; however the level of efficacy varied among the treatments. In general, the combinations of two fungicides spray i.e. mancozeb at 45 DAS followed by other four fungicides each at 60 DAS have recorded lower Alternaria blight severity as compared to all single spray treatments. Foliar spray with mancozeb (0.2%) at 45 DAS followed by hexaconazole (0.05%) at 60 DAS was found most effective in controlling Alternaria leaf blight severity up to 78.0 percent and Alternaria pod blight severity up to 56.5 percent and increased seed yield upto 29.9 percent as compared to untreated control.