Efficacy of certain chemical insecticides against tomato fruit borer, Helicoverpa armigera of tomato

Our findings on the increased larval mortality due to cypermethrin in oil fed larvae may be due to the oils inhibit the enzymes like mixed function oxidases (mfo), Investigations were carried out at the Central Research Farm, Allahabad School of Agriculture, Sam Higginbottom Institute of Agriculture, Technology and Sciences, Allahabad during the Rabi season 2010-2011 in tomato to evaluate the efficacy of Endosulfan, certain biocontrol agents and neem (Azadirachta indica) against tomato fruit borer, Helicoverpa armigera. Among the different sprays, listed above, least number of larvae (0.17/plant) was observed in Endosulfan, which was proved to be capable in suppressing the pest incidence effectively. Similarly among the various bio-control based treatments, Bacillus thuringiensis proved to be the second best, where the least number of larvae (0.27/plant) were observed, followed by HaNPV and NSKE. Different combinations of HaNPV and Beauveria bassiana were least effective when compared to others, which proved to be ineffective in suppressing the pest incidence effectively. Similarly when extent of fruit damage was taken into consideration, Endosulfan resulted in least fruit damage 7.62 per cent, followed by Bacillus thuringiensis 7.87 per cent, which was proved to be next best effective treatment in evaluating the least fruit damage.