Efficacy of novel insecticides against shoot and fruit borer complex, Earias vittella (Fab.) and E. Insulana Boisd. In Okra
摘要
Among various insect pests attacking okra, shoot and fruit borer complex, Earias vittella and E. insulana cause substantial crop losses. To identify more effective control option for these pests, a study was conducted over two consecutive years to evaluate the efficacy of some novel insecticides viz., chlorantraniliprole 18.5% SC, emamectin benzoate 5% SG and pyridalyl 10% EC against Earias spp in comparison to traditional ones such as λ-cyhalothrin 5% EC, cypermethrin 25% EC and quinalphos 25% EC. Each insecticide was applied to okra crop thrice at recommended dose of 25, 6.75, 50, 15, 37, and 200 g a.i. ha−1, respectively. Results revealed that chlorantraniliprole exhibiting significant reduction in shoot infestation (73.37%) and fruit infestation (82.60 and 80.14% on number and weight basis, respectively) was most effective against Earias spp., and caused maximum increase (62%) in yield of marketable okra fruits. It was followed by emamectin benzoate and pyridalyl with notable effectiveness. Conversely, λ-cyhalothrin, cypermethrin and quinalphos were comparatively less and almost equally effective. Incremental cost benefit ratio was however, highest in treatment involving emamectin benzoate (1:15.49) followed by λ-cyhalothrin (1:12.40) and chlorantraniliprole (1:11.52) while minimum in treatment involving pyridalyl (1:7.25). Thus, chlorantraniliprole and emamectin benzoate can be used alternatively for the efficient management of Earias spp. in okra.