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

Abstract

A 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).