EFFICACY OF TRANSGENIC BT COTTON HYBRIDS ON PINK BOLLWORM, PECTINOPHORA GOSSYPIELLA (SAUNDERS) UNDER IRRIGATED AND RAINFED CONDITIONS OF SOUTH AND CENTRAL INDIA

摘要

Present study was performed to evaluate the efficacy of the Bollgard II cotton hybrids against the pink bollworm, Pectinophora gossypiella. This study was carried out using seven second generation Bt genotypes and their respective Non Bt genotypes during winter and summer seasons of 2008 and 2009 under irrigated conditions of South India. Also infestation of pink bollworm population was recorded on three popular hybrids namely MRC-6301 Br, RCH2 BG-II and RCH2 Non Bt during K/7ar7r"2012-2013 under rain fed conditions of Central India. Locule damage was significantly higher in non Bt hybrids than in Bt hybrids at 90 and 120 DAS. An increase in locule damage and larval population was recorded in summer season as compared to winter crop. Laboratory studies also revealed that, the maximum number of entry holes/boll and number of surviving larvae / boll were nil in Bt hybrids and 8.67and 4.67, respectively in RCH 2 Non Bt. Under rainfed condition, the incidence of P. gossypiella was nil in Bt hybrids andsignificant infestation was noted in non Bt hybrid. Peak activity of pheromone trap catches of P. gossypiella was recorded during 2nd fortnight of February in winter season in South India and under Nagpur conditions, the pheromone trap catches of pink bollworm were recorded from first week of October to last week of February during the cropping season. In general the current study clearly indicatesthe susceptibility of P. gossypiella to transgenic cotton hybrids.