Effect of different granular insecticides on suppression of rice stem borers and plant hopper under rice-wheat cropping system

Abstract

Field experiments were conducted at three different locations in central Punjab, Pakistan to evaluate the efficacy of different granular insecticides on suppression of rice stem borer (Scirpophaga incertulas & Scirpophaga innotata) and plant hopper (Nilapervata lugens & Sogatella forcifera ) for two years (2018 and 2019) during Kharif season. Treatments comprised different granular insecticides; Cartap 4% G, Fipronil 0.3 G, Mover Plus 4.3 % (fipronil 0.3 % + cartap hydrochloride 4%) and Virteko 0.6 GR (chlorantraniliprole 0.2 % + thiamethoxam 0.4 %) @ 22.0, 20.0, 11.0 and 10 kg ha-1 respectively. All the insecticides showed varied efficacy against rice stem borer and plant hopper in minimizing the symptoms of dead hearts, white heads and hopper burn. The highest suppression efficacy was recorded with the chlorantraniliprol + thiamethoxam followed by fipronil + cartap hydrochloride against plant hoppers and stem borers. Experimental units treated with chlorantraniliprol + thiamethoxam showed the lowest hopper infestation (9,11 and 8 hoppers per plant) as compared to control where 70, 75 and 68 hoppers per plant was recorded for location I, II and III, respectively. Granular insecticide i.e. chlorantraniliprol + thiamethoxam also reduced the stem borer infestation @ 76, 81 & 78 % at location I, II and III respectively. The experimental unit treated with chlorantraniliprol + thiamethoxam showed a 22% (4266.6 kg ha-1) and 23% (4288.3 kg ha-1) higher paddy yield than control for 2018 and 2019, respectively.