DefinePK

Abstract

Three Bacillus thuringiensis biopesticides were sprayed at their recommended rate against cotton bollworms, which have controlled these pests effectively both in lab and field trials. In the lab CAMB-Bt was found the best biopesticide giving 100% mortality with in 48hrs against spotted bollworms. Similarly Lepinox-Bt gave 100% mortality against spotted bollworm. However it was least effective against American bollworm with less than 60 % killing. Comparatively Larvo-Bt gave ≤ 20% mortality against both the insects. There were made 3 sprays of Bt on cotton crop. In the field four days after each spray CAMB-Bt rank Ist by giving (65, 34 and 32%) mortality. While second was Larvo-Bt giving (62, 28 and 30%). Lepinox-Bt ranked 3rd (53, 2 and 26%). After three sprays the residual efficacy of CAMB-Bt was (55, 26 and 15%) followed by Larvo-Bt having (26, 29 and 13%) mortality. While Lepinox-Bt has (49, 3 and 1%) mortality as compared to control (11, 14 and 7.5%).The results suggests that CAMB-Bt is more effective than imported Bt formulations.