Evaluation of combination insecticides for managing the insect pest complex in okra (Abelmoschus esculentus)

AbstractA field investigation was undertaken to determine the efficacy of certain combination insecticides against insect pests of okra. Among the combination insecticides tested, the imidacloprid 40% + fipronil40%WG @ 500g/ha was observed to be the most effective against whitefly (Bemisia tabaci) with mean population of whitefly (2.24±0.06 per 3leaves; 1.61±0.12 per 3 leaves, 77.51% & 82.48% PROC, after first and second spray, respectively), jassid (Amrasca biguttula biguttula)with mean population of jassid (1.87±0.29 per 3 leaves; 1.21±0.22 per 3 leaves, 77.17% & 84.89% PROC after first and second spray, respectively) and shoot and fruit borer damage (Earias vittella) with lowest mean damage (3.40±0.13 per cent shoot damage and 2.61±0.07 per cent fruit damage, 71.36% & 78.87% PROC after first and second spray, respectively) and least effective treatments was profenofos 40% + Cypermethrin 4% EC 1250 ml/ha against whitefly and jassid, deltamethrin0.72%+ buprofezin5.65% EC500ml/ha against shoot and fruit borer. The maximum yield of 95.27 q/ha was found in imidacloprid 40% + fipronil 40% WG 500 g/ha, while the minimum yield of 85.83 q/ ha was recorded in deltamethrin 1% + triazophos 35% EC 1000 ml/ha. Untreated plot recorded the yield 60.13 q/ha. The highest incremental cost-benefit ratio of 1:21.21 was recorded in thiamethoxam 12.6% + lambda cyhalothrin 9.5% ZC125ml/ha, while the lowest ratio was observed in imidacloprid 40%+ ethiprole40% WG 500 g/ha (1:3.33).