Neem Based Pest Management Strategy in Cotton System

Eight different spray schedules were tested against bollworms in cotton system during 1993 and 1994 and their impact was studied on the build up of whitefly population. Neem alone or when used alternately with Bt or with conventional synthetic insecticides failed to check bollworms, however, no build-up in whitefly population was noted. Alternate use of conventional insecticides with synthetic pyrethroids proved effective against bollworms but whitefly resurgence was evident. However, spray schedule in which neem was used alternately with Bt and atleast one spray of synthetic pyrethroid proved as effective as previous treatment in managing bollworm complex without resurgence of whitefly. Further studies showed satisfactory control of bollworms and cotton yield response by alternate use of Neem, Bt and a 84% reduced rate of synthetic pyrethroid. This spray schedule has no adverse effect on environment.