Studies on the control of Alternaria blight in rapeseed-mustard with some new chemicals.

Alternaria blight disease is the major constraint in the production around the world. An experiment was conducted at Regional Research Station, Gurdaspur during Rabi, 2010–11. In the present study,the efficacy of chemicals viz Score (Triazole group), Amistar (Strobilurin group) and Indofil M-45 was evaluated against Alternaria blight disease of rapeseed-mustard under Gurdaspur conditions in Punjab during Rabi season of 2010–11. Lowest mean disease severity of 9.3% on leaves and 6.0% on pods was observed when two sprays of Score @0.1% were given at 15 day interval starting at 75 days after sowing, thus resulting in significant control of the disease on leaves (89.35%) and pods (88.74%). It was followed by Score (73.31%) on leaves when sprayed along with Indofil M45 at 10 day interval (first spray of Indofil M45@0.25%+ second spray of Score@0.1% + third spray of Indofil M45@0.25%). Amistar @0.1% also gave a good control of the disease. Besides significant disease control, the effective treatments also resulted in an significant increased seed yield of the.