Bioefficacy of botanical and chemical insecticides against brown planthopper, Nilaparvata lugens (Stal) (Hemiptera: Delphacidae), in paddy crop
Abstract
The present study was conducted to evaluate the bioefficacy of botanical and chemical insecticides against brown planthopper, Nilaparvata lugens (Stal), in paddy. The experiment was conducted using the following treatments Azadirachtin 5 % (60, 70 and 80 mL), BrahamAstra (7.5, 10.0 and 12.5 L), homemade neem (2.0, 3.0 and 4.0 L), Oshean 20 SG (80 g) and an untreated control. Two sprays were applied, the first at the initial appearance of the pest and the second at the economic threshold level (ETL). Oshean 20 SG (80 g) recorded the lowest brown planthopper population and the maximum percentage reduction over the control after both sprays. Among different treatments, Azadirachtin (5 %) at 80 mL dose recorded lowest brown planthopper population. All botanical insecticides were safe for the spider population. Grain yield was recorded higher in Oshean 20 SG treatment followed by the botanical insecticides. Azadirachtin 80 mL proved to be the most effective and environment friendly alternative for brown planthopper management in paddy.