Performance of Bt and Non Bt Cotton hybrids against pink bollworm, Pectinophora gossypiella

摘要

The experiment was conducted at Main Agricultural Research Station, Dharwad, during 2004-05 and 2005-06. In all the Bt cotton hybrids, the rosette flowers, larval population, green boll damage, locule damage were significantly low compared to their non-Bt cotton counter parts. Among all the Bt cotton genotypes, significantly lower pink bollworm larvae, green boll damage and locule damage were registered in RCH-2 Bt (5.6 larvae/50 bolls) being on par with RCH-20 Bt (6.4 larvae/50 bolls, 17.3% and 17.0%, respectively) and RCH-144 Bt (8.8 larvae/50 bolls). Significantly higher number of larvae, highest green boll damage and locule damage were recorded in DHB-290 (29.1 larvae/50 bolls, 39.3% and 34.5%, respectively) being on par with DHH-11 (25.4 larvae/50 bolls). The seed cotton yield among Bt cotton hybrids rangedfrom 6.7 to 10.3 q/ha, which was significantly superior to their non-Bt counter parts.