Field efficacy of quinalphos 25% EC against sucking pests and its phytotoxicity on Chilli in Karnataka

Abstract

Insect pests are important constraint for chilli production such as sucking pest complex of thrips, Scirtothrips dorsalis Hood, yellow mite, Polyphagotarsonemus latus (Banks) and aphid, Aphis gossypii Glover. Chemical method of control is one of the promising method to control pests. The present work aimed to control sucking pests like thrips, mites and aphids by Quinalphos 25% EC. The experiment was laid out in a randomized block design (RBD) with three replications. Two days after third spray lowest population thrips population was recorded in the treatment with Quinalphos 25% EC at 750 g.a.i/ha (0.83thrips/leaf), which was on par with the treatment Fipronil 5 % SC (1.20thrips/leaf) and Quinalphos 25% EC at 375 g.a.i/ha (1.25thrips/leaf). Ten days after third spray Quinalphos 25% ECat 750 g.a.i./ha, Diafenthiuron 50%WPat 300 g.a.i./ha, Quinalphos 25% ECat 375 g.a.i./ha and Quinalphos 25% ECat 325 g.a.i./ha recorded significantly lowest mites population ranged from 0.60 to 0.80 mites/leaf respectively. The application of Quinalphos 25% EC did not caused any phytotoxic effect on chilli crop at various dosages @ 375-750 g a.i./ha. Among the different treatments, significantly highest yield was recorded in the treatment Quinalphos 25% EC at 750 g.a.i./ha with 21.25 q/ha. The study indicated that Quinalphos 25% EC is effective against aphids (Aphis gossypii) thrips (Scirtothrips dorsalis) and mites(Polyphagotarsonemus latus) a in chilli @ 375 g a.i./ha. The study showed no build-up of resistance / resurgence of target sucking pests like aphids, jassids, mites and thrips.