Screening of genotypes against Alternaria blight of rapeseed-mustard and its fungicidal management

Alternaria blight is destructive disease of rapeseed- mustard caused by Alternaria brassicae (Berk) Sacc. and A. brassicicola (Schw). The field experiments were conducted during 2013-14 and 2014-15, with 200 genotypes for evaluation of their resistance to Alternaria blight, as well as to develop effective management strategies for this disease. None of the genotypes were found disease free or highly resistant, only 7 genotypes namely (DLSC-1, DRMR-261, DRMR-270, GSC-101, GSL-1, NPC-20 and PHR-2) were found resistant, 15 genotypes were rated as moderately resistant. Rest of the genotypes was either recorded susceptible or highly susceptible.For disease management, newly molecules of 6 fungicides were evaluated with 13 treatments combinations for their effectiveness. Propiconazole 25% EC @ 0.10% was found most effective in reducing the disease severity followed by same fungicide @ 0.05%. It was followed by Hexaconazole 5% SC @ 0.010%. Maximum test weight and yield was also recorded with the sprays of Propiconazole 25% EC @ 0.10% followed by same fungicide @ 0.05%. In comparison to other fungicides, the maximum B:C ratio was recorded with three sprays of Hexaconazole 5% SC @ 0.05% followed by Propiconazole 25% EC @ 0.05%.