Estimation of yield losses and bioefficacy of some novel insecticides against leaf hopper, Amrasca devastans in transgenic cotton

Abstract

Estimation of yield losses and Field efficacy of novel insecticides against leafhoppers on transgenic cotton were assessed during kharif 2011. Estimation of yield losses due to, leafhoppers, in RCH-2BG-II, RCH-2NBt, Tulasi-9BG-II and Tulasi-9NBt under protected and unprotected conditions was done with eight treatments and three replications in Factorial Randomized Block Design. RCH-2 was susceptible and Tulasi-9 was tolerant hybrid against leafhoppers. Among the treatments; Tulasi-9 NBt recorded lowest yield loss (13.13%) and RCH-2NBt recorded highest yield loss (19.99%) followed by Tulasi-9 BG-II and RCH-2 BG-II. The bioefficacy of certain novel insecticides against leafhopper recorded Fipronil 5% SC @50g a.i. ha-1 and fipronil 80% WG @50g a.i. ha-1 were effective in managing leafhopper with a population reduction of 70.9% and 67.6%, respectively.