Efficacy of New Formulations of?Bacillus thuringiensis?Var.?Kurstaki?(HD-1) against?Helicoverpa armigera?(Hubner)

摘要

Bioassays were conducted under laboratory conditions at Division of Entomology, Indian Agricultural Research Institute, New Delhi during 2008, to access the efficacy of new weattable powder (WP) formulations of?Bacillus thuringiensis?var.?kurstaki?(HD-1) against IIIrd?instar larvae of?Helicoverpa armigera?(Hubner). Sixteen new WP formulations of?B. thuringiensis?var.?kurstaki?(HD-1) were developed and relative efficacy was calculated in the basis of LC50 values. The results revealed that LC50 values of recipe-2 (0.032%), recipe-7 (0.018%), recipe-9 (0.030) and recipe-15 (0.015%) were highly effective against IIIrd?instar larvae of?H. armigera?in comparison to Dipel? 8L (0.037%) and Biolep? (0.046%), a commercial formulation of?B. thuringiensis?var.?kurstaki. On the basis of laboratpry performance, recipe-7 and recipe-15 were selected for field efficacy against?H. armigera?in pigeonpea crop. Recipe-15 was found significantly more effective than the Dipel?8L under the conditions.