EVALUATION OF SOME CHEMICAL AND NON- CHEMICAL MANAGEMENT PRACTICES AGAINST THE EPILACHNA BEETLE IN BRINJAL

Abstract

An experiment was conducted to evaluate of some chemical and nonchemical management practices against the epilachna beetle attacking brinjal at the experimental farm of Sher-e-Bangla Agricultural University. The study comprised seven treatments such as mechanical control, Cypermethrin 10 EC, Sevin 85 SP, Chlorpyriphos 20 EC, neem seed kernel, mechanical control with application of neem seed kernel and an untreated control. The experiment was carried out in Randomized Completely Block Design (RCBD) with three replications. Sevin 85 SP, Cypermethrin 10 EC and Chlorpyriphos 20 EC reduced more than 90% of the epilachna beetle population in the brinjal field. Mechanical control in combination with neem seed kernel spray also provided more than 80% reduction of the pest. Sevin 85 SP gave the highest fruit yield (20.0 tlha) of brinjal but Cypermethrin 10 EC and Chlorpyriphos 20 EC produced 19.90 tlha and 16.20 tlha yield, respectively. Sevin and Cypermethrin also increased more than 200% yield of brinjal over control. Chlorpyriphos and mechanical control with neem seed kernel application increased more than 150% brinjal yield. Negative linear relationship was observed between percent leaf infestation and yield, and percent plant infestation and yield of brinjal. The highest benefit-cost ratio (12.34) was observed in Sevin 85 SP. Almost equal BCR was calculated in Cypermethrin and Chlorpyriphos (7.38 and 7.34, respectively) treated plots. Mechanical control with application neem seed kernel, and neem seed kernel only gave the BCR of 5.39 and 4.89, respectively. The lowest BCR 2.37 was obtained in mechanical control plots. Sevin 85 SP, Cypermethrin 10 EC and Chlorpyriphos 20EC had strong negative impact on the natural enemy population. Mechanical control with application neem seed kernel, and neem seed kernel had moderate effect on natural enemies.