Abstract

                                A study was carried out to test the bio-efficacy of neem oil at 0.10 to 0.50 per cent concentrations alone and in combination with the pyrethroid deltamethrin (0.09% ) on cotton CMCN 5) under field condition during winter 1986-1987. Deltamethrin (0.09%) was the most effiective treatment in minimising shoot, square, bolls, kapas and loculi infestation due to E. vittella. The next best treatments were neem oil at 0.5% alone and combinations of neem oll 0.30, 0.40 and 0.50% with deltamethrin 0.09%. Deltamethrin 0.09% spray recorded the maximum yield. Deltamethrin in com- bination with neem oil recorded higher yield than neem oil alone. Yield loss was minimum in detalmethrin 0.09% alone. Deltamethrin 0.09% alone can be used for effective control of bollworms and realising appreciably high yield of kapas. Addition of neem oil and deltamethrin spray fluid has not conferred any additional benefits.

Key words : COTTON, SPOTTED BOLLWORM, NEEM OIL, DELTMETHRIN