EFFECT OF VARIETIES OF MUSTARD AND CHEMICAL INSECTICIDES ON THE INFESTATION OF APHID

Abstract

This study was conducted to investigate the effect of varieties of mustard and chemical insecticideson the infestation of mustard aphid Lipaphiserysimi (Kalt) during the period from November 2012 to February 2013 at the Sher-e-Bangla Agricultural University farm, Dhaka.The study consisted of five treatments and two varieties.These were as follows:T1: (Spraying of Dursban 25EC @ 2.5ml/L of water),T2:(Spraying of Malathion 57EC @ 2.5ml/L of water), T3: (Spraying ofSumi- Alpha 5EC@ 1ml/L of water), T4: Spraying of Sevin 85 SP @ 2.5g/L of water and T5: (Untreated Control) treatment and all the spraying were done at 15 days interval. Two varieties were BARI shorisha-9 and BARI shorisha-11.The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications. The result revealed that among the treatment combinations, T3V2 (Sumi-Alpha + BARI shorisha- 11) was the most effective in controlling mustard aphid (85.78%) after first spray and (88.11%) after second spray. On the other hand T4V2(Sevin + BARI shorisha-11) was less effective in controlling mustard aphid(71.45%) after first spray and (67.11%) reduction of aphid population after second spray. The combination of Sumi-Alpha and BARI shorisha-11 was better in terms of controlling mustard aphid L. erysimi and yield of mustard.