Efficacy of biopesticides alone and in combination with conventional insecticides against cotton bollworms

摘要

Field experiments conducted during kharif 1998 adn 1999 to evaluate the effcacy of commercial formulation of Bacillus thuringiensis (Dipel) and nuclear polyhedrosis virus of Helicoverpa armigera (HNPV) alone or in combination with endosulfan at normal and half doses against cotton bollworms have revealed that four spray schedule of HNPV (500 LE) alternated with endosulfan (0.05 percent) was most effective by recording lowest bollworm infestation and highest seed cotton yield with maximum profit. Thesole application of Dipel and HNPV were ineffective in managing bollworms.