Bioefficacy of Chlorantraniliprole against Yellow Stem Borer and Leaf Folder and Persistence in Basmati Rice

Abstract

Chlorantraniliprole being a systemic insecticide is recommended for the management of the yellow stem borer, Scirpophaga incertulas (Walker) and leaf folder, Cnaphalocrocis medinalis (Guenee). Its bioefficacy against these insects is reported for two years (2011–12) in basmati rice at four doses, viz., 50, 100, 150, 200 mL ha−1. Per cent reduction of stem borer and leaf folder was 31.88, 62.66, 68.12, 77.60 and 71.29, 73.53, 77.42, 80.68, respectively, 15 d after spray on basmati rice. Its persistence on basmati rice following applications @ 30 and 60g a.i. ha−1, 30 d after transplanting, is also reported. For residue analysis, samples of basmati rice plants were collected at 0, 1, 3, 5, 7, 10, 15 and 20 d after application of the insecticide. Chlorantraniliprole in rice plants was found to be below determination limit of 0.05 mg kg−1 at 15 and 20 d after application at the recommended and double the recommended doses, respectively. Basmati grains, bran, husk and straw at harvest time did not reveal the presence of detectable residues of chlorantraniliprole.