Bio-Efficacy and Dissipation of Newer Molecules Against White Fly in Okra.

Experiments were conducted during kharif, 2013 to evaluate the efficacy of six insecticides viz., bifenthrin 10 EC at 80 g a.i. ha -1 , fipronil 5 SC at 500 g a.i. ha -1 , flubendiamide 480 SC at 60 g a.i. ha -1 , quinalphos 25 EC at 350 g a.i. ha -1 , profenofos 50 EC at 400 g a.i. ha -1 and beta-cyfluthrin 25 SC at 18.75 g a.i. ha -1 against white fly Bemisia tabaci (Gennadius) on okra of which flubendiamide @ 60 g a.i./ha, profenofos @ 400 g a.i./ha and beta-cyfluthrin @ 18 g a.i./ha, applied twice as foliar sprays were found to be most effective in controlling the okra pests, hence the dissipation studies were conducted for these three insecticides. The dissipation pattern was studied by collecting okra fruits at 0, 1, 3, 5, 7, 10 and 15 days after last spray and analyzed at AINP on Pesticide Residues, Rajendranagar, Hyderabad The initial deposits of flubendiamide at 60 g a.i. ha -1 sprayed at 50 % flowering and repeated 15 days after first spray recorded 1.49, mg kg -1 which dissipated to below detectable level (BDL) on 10 th day. The initial deposit of profenofos (400 g a.i./ha) in okra fruits was 1.52 mg/kg which degraded to 0.09 by 7 th day after last spraying. The initial deposit of beta-cyfluthrin (18.75 g a.i./ha) in okra fruits was 0.11 mg/kg and by one day after treatment dissipated by 45.04 per cent.