EFFECTIVENESS OF SOME INSECTICIDES FOR CONTROLLING ONION THRIPS (Thrips tabaci) FOR QUALITY SEED PRODUCTION

Abstract

The experiment was conducted in the central farm of Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka-1207 during the period from November 2012 to February 2013 to evaluate some promising insecticides against onion thrips. The treatments were T1= Fipronil @ 2.0 ml/L of water at 7 days interval, T2= Lambdacyhalothrin @ 1.0 ml/L of water at 7 days interval, T3= Imidacloprid @ 0.5 ml/L of water at 7 days interval, T4= Neem Oil @ 4.0 ml/L of detergent at 7 days interval, T5= Malathion 57 EC @ 2.0 ml/L of water at 7 days interval, T6 = Sevin 85WP @ 2.0 ml/L of water at 7 days interval, T7 = Control. The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The result revealed that T2 comprising Lambdacyhalothrin @ 0.5 ml/L of water at 7 days interval performed as the best treatment in reducing thrips population (78.86%) and also increasing flower/stalk, scape diameter, umbel diameter of onion and thousand seed weight. T1 comprising spraying of Fipronil @ 2.0 ml/L of water at 7 days interval performed satisfactory result in reducing thrips population (76.65%) and also increasing plant height, leaves per plant, scape length, umbel number, flower per umbel, effective flower per umbel, Seed weight (mg) /plant and yield of onion. Spraying of Imidacloprid @ 0.5 ml/L of water at 7 days interval also performed good result in reducing thrips population (72.68%) followed by Neem Oil @ 4.0 ml/L with detergent at 7 days interval, reducing thrips population (45.43%).