Screening of BT cotton hybrids against bollworms

A field experiment was conducted during 2005–07 to screen Bt hybrids for their reaction against cotton bollworms at Regional Agricultural Research Station, Raichur. MRC-735 IBt recorded significantly lowest larval population of 0.07 per 10 bolls which was on par with RCH-371Bt, RCH-20Bt, RCH-144Bt, RCH-138Bt, RCH-368Bt, MRC-6322 Bt and NCS-145Bt. Overall the incidence of P. gossypiella was negligible in all the Bt hybrids. Non Bt version of NCS-145 recorded significantly highest larval population of 3.38 larvae per 10 bolls. RCH-144Bt recorded significantly highest seed cotton yield of 19.60 q/ha and was on par with RCH-2Bt, RCH-371Bt, RCH-20Bt, RCH-368Bt, MECH 162Bt and MRC-7201Bt. Non Bt NCS 145 recorded minimum seed cotton yield of 5.60 q/ha.