Combined performance of okra cultivars and certain insecticides for management of Earias vittella (Fabricius) (Lepidoptera: Noctuidae) in Assam, India

Abstract

The purpose of this study was to see the effectiveness of certain insecticides and three popular okra cultivars against Earias vittella, the major insect pest of okra. The experiment was carried out at the Experimental Farm, Dept. of Horticulture, Assam Agricultural University, Jorhat, Assam during the kharif, 2020 and the spring-summer, 2021. It was found that there was significant role of trichome present in adaxial and abaxial side of leaves in the okra varieties Arka Anamika, Pusa Sawani and S-51. In control plots, the population of insect pests and the percentage of fruit infestation increased over time. Treatment lambda cyhalothrin 5% EC @ 15 gm a.i./ha + S-51 had the highest percentage of fruit infestation (12.33% in kharif and 10.33% in spring-summer). Treatment chlorantraniliprole 18.5% SC @ 25 gm a.i./ha + Arka Anamika had the highest average yield (58.70q/ha) and benefit-cost ratio (3.08: 1). The study demonstrated that in terms of trichome density, there was no considerable difference among the varieties, except in the case of Arka Anamika. Whereas there was a significant difference in insecticidal treatments for the management of Earias vittella, the insecticide chlorantraniliprole 18.5% SC proved to be the most effective insecticide followed by emamectin benzoate 5% SG.