Biological compatibility of Beauveria bassiana (Balsamo) Vuillemin isolate with different insecticides and neem formulations commonly used in rice pest management

摘要

Compatibility of Beauveria bassiana (Balsamo) Vuillemin (isolate BbCm KKL 1100) with twelve insecticides and three neem formulations was examined on agar plate to develop suitable combinations for the management of insect pests in rice fields. All chemical and botanical insecticides inhibited mycelial growth of B. bassiana either partially or completely depending on their concentrations (10X, IX and 0.1X, where X = treated concentration). Chemical insecticides completely inhibited the mycelial growthof B. bassiana, while the neem formulations inhibited 70-86% biomass production of the fungus at 10X concentration. At IX concentration, carbofuran caused total inhibition, but all other insecticides caused 47.4-75.5% inhibition. However, at 0.1X concentration, only neem seed kernel extract, chlorpyriphos and dimethoate exhibited 22.2%, 27.3% and 32.6% mycelial inhibition, respectively, and these could be used with B. bassiana in the field condition.