Dahiya, K.K.Meenu2018-10-172018-10-172018http://krishikosh.egranth.ac.in/handle/1/5810081690The present study was conducted at Chaudhary Charan Singh Haryana Agricultural University, Hisar, Haryana (India). Present investigations revealed that the sucking pests (whitefly, leafhopper, thrips) remained active throughout the crop season with little differences among them. It was observed that the sucking pests remained active from 25th to 41st standard meteorological weeks (SMW i.e., June to October) during kharif 2016 and 2017.The data on the population/incidence of cotton whitefly revealed that whitefly did not crossed it's economic threshold level on all the 6 genotypes of cotton during kharif 2016 while it crossed the economic threshold level during kharif 2017 in all the 6 cotton genotypes. The maximum adult population of whitefly was recorded at 32nd SMW during both the kharif seasons of 2016 and 2017. The maximum mean incidence was recorded in RCH-650 BGII during 2016 and 2017. Mean leafhopper population, on all the six genotypes was ranged from 2.02-5.35 and 3.16-5.33 nymphs/leaf during 2016 and 2017, respectively. During 2016, the peaks were observed on 27th and 29th SMW, while peaks were recorded during 2015 in 26th and 29th SMW. Genotype HD-432 had 2.12 and genotype AAH-1 had 3.32 nymphs/leaf during 2016 and 2017, respectively. The thrips population was commenced at 25th SMW during 2016 and 2017, respectively. The peak incidence of thrips population was recorded on 33rd and 31st during 2016 and 2017, respectively. All the sucking pests’ population was higher in Bt hybrids. Peak of natural enemies was observed in 32nd SMW during 2016 and 2017. Minimum bollworms infestation was recorded in RCH-650 BGII during 2016 and 2017. Whitefly population was significantly and negatively correlated with rainfall, leafhopper population was significant and positively correlated with rainfall, thrips population was positively and significantly correlated with sunshine hours and bollworms population was negative and significant correlated with minimum temperature, RH(e) and wind speed during 2016. During 2017, whitefly and thrips significantly and negatively correlated with rainfall. Bollworms population was negatively and significantly correlated with minimum temperature, RH(e) and wind speed. Whitefly and thrips population showed significant and positive correlation with sugar content of leaves and crude protein in cotton seeds while leafhopper showed negative and significant correlation with sugar content of fruiting bodies. Bollworms had positive and significant correlation with crude protein in cotton seeds. Pyriproxyfen, imidacloprid and difenthiuron were found to be most effective insecticides for managing sucking pests while, botanicals were found to be comparatively safer to the natural enemies population.ennullThesis