DefinePK

Abstract

Seven genotypes of cotton viz BH-124, BH-121, BH-125, BH-147, SLH-257, SLH-244 and NIAB-98 were studied for resistance/susceptibility against jassid (Amrasca devastans Dist) during 2002. BH-125 showed maximum population of jassid nymph (1.05/leaf), while SLH-257 appeared as resistant (0.63/leaf), Maximum jassid adult was recorded on BH-121 {0.17/leaf), and minimum on NIAB-98 (0.04/leaf). Maximum temperature exerted significant and negative effect on jassid nymph in case of SLH- 267. Minimum and average temperatures and relative humidity showed positive and significant correlation with jassid adult with r-values of 0.592, 0.532 and 0.581, respectively in case of NIAB-98 The effect of average temperature and rainfall was also significant and positive on jassid adult for BH-121 and SLH-257, respectively. All the abiotic factors when computed together exerted 18.7 and 6.4 percent role in population fluctuation of jassid nymph and adult, respectively.