Efficacy of Chemical and Bio-insecticides against Major Insect Pests of Brinjal, Solanum melongena Linn.

The relative efficacy of nine chemical and bio-insecticides against the major insect pests of brinjal (Solanum melongena Linn.) is reported. Maximum reduction of jassid, Amrasca biguttula biguttula (Ishida) and whitefly, Bemisia tabaci (Genn.) was observed in the imidacloprid (90.04%, 91.52%) and acephate (87.80%, 89.71%) treatments, respectively. The minimum reduction of jassid and whitefly was observed in the plots treated with Bacillus thuringiensis var. kurstaki, Metarhizium anisopliae and Beauveria bassiana. The shoot infestation by Leucinodes orbonalis Guen. was minimum in the spinosad (1.52%) and acephate (2.91%) treatments. A satisfactory protection to fruits was provided by spinosad (5.39% fruit infestation) and acephate (5.52% fruit infestation). The highest yield was recorded in the plots treated with spinosad, (199.12 q ha⁻¹) which was at par with acephate (197.09 q ha⁻¹) and imidacloprid (189.93 q ha⁻¹). The maximum benefit-cost ratio was recorded in acephate 0.037% (42.07) followed by imidacloprid 0.005% and NSKE, with benefit-cost ratios of 26.49 and 19.19, respectively.