Effect of imidacloprid 17.8 SL against whiteflies and thrips in cotton

Abstract

Two field experiments were conducted to assess the effect of imidacloprid 17.8 SL against whiteflies and thrips in cotton. The treatment schedule included three different doses of imidacloprid 17.8 SL at 15, 25 and 50 g a.i. ha-1 along with standard checks viz., imidacloprid (Tatamida®) at 25 g a.i. ha-1 and methyl demeton at 125 g a.i. ha-1 and their efficacy was compared with untreated check. The pre- and post treatment counts were recorded on 1, 3, 7, 10 and 14 days on the incidence of whiteflies and thrips. The results revealed that the order of efficacy of different insecticides against whiteflies and thrips were as follows: imidacloprid 17.8 SL @ 50 g a.i. ha-1 > imidacloprid (Tatamida®) @ 25 g a.i. ha-1 > imidacloprid 17.8 SL @ 25 g a.i. ha-1 > thiamethoxam @ 25 g a.i. ha-1 > imidacloprid 17.8 SL @ 15 g a.i. ha-1 > methyl demeton at 125 g a.i. ha-1 (whiteflies) and imidacloprid 17.8 SL @ 50 g a.i. ha-1 > imidacloprid 17.8 SL @ 25 g a.i. ha-1 > imidacloprid (Tatamida®) @ 25 g a.i. ha-1 > thiamethoxam @ 25 g a.i. ha-1 > imidacloprid 17.8 SL @ 15 g a.i. ha-1 > methyl demeton at 125 g a.i. ha-1 (thrips). Though the double dose of imidacloprid 17.8 SL @ 50 g a.i. ha-1 showed higher efficacy against whiteflies and thrips, the recommended dose of imidacloprid 17.8 SL @ 25 g a.i. ha-1 was found to be effective in controlling whiteflies and thrips in cotton followed by thiamethoxam @ 25 g a.i. ha-1.