Performance of BG-I and BG-II Bt Cotton hybrids againstAphis gossipiandAmrasca bigutulla bigutulla

Abstract

Among all BG-I Bt cotton hybrids, aphid population ranged from 7.18 to 17.58/three leaves. Minimum aphid population was recorded on ACH-155 (7.18) and maximum on RCH-2 (17.58). Among BG-II cotton hybrids, aphid population ranged from 7.63 to 19.70/three leaves. Minimum aphid population was observed on ACH-155 (7.63) and maximum on MRC-7326 (19.70). Among all Bt cotton (BG-I and BG-II) hybrids, aphid population ranged from 7.18 to 19.70/three leaves. Minimum aphid population was observed on ACH-155 BG-I (7.18) which was found significantly superior over rest of hybrids except SP-499 BG-I (7.29), SP-1037 BG-I (7.30) and ACH-155 BG-II (7.63) which were at par with each others. Maximum population of aphid was observed on MRC-7326 BG-II (19.70) over rest of hybrids except UPLHH-2 BG-II (18.24), RCH-2 BG-II (18.06) and RCH-2 BG-I (17.58) which were at par with each others. The jassid population on BG-I Bt hybrids ranged from 1.50 to 5.64/three leaves, minimum being on ACH-21-1-BG-I (1.50/three leaves) and maximum on RCH-2 BG-I (5.64/three leaves). Among BG-II hybrids it ranged from 1.95 to 6.95/three leaves, minimum being on MRC-7326 BG-II (6.95/three leaves), followed by VBCH-1501 BG-II (6.52/three leaves). Among all Bt cotton hybrids jassid population ranged from 1.50 to 6.95/three leaves.