author(s)
Roomi Rawal, KK Dahiya, Adesh Kumar and Varun Saini

abstract
The present field trial was conducted to establish the effect of ecological factors on the infestation of bollworms on seven varieties of genetically/non-genetically modified cotton at Research Farm of cotton section, Department of Genetics and Plant Breeding, Chaudhary Charan Singh Haryana Agricultural University, Hisar, India during the crop season 2014-15. The Bollworms squares infestation observation was started from started from 30^th Standard Meterological Week (SMW) and continued till harvesting of crop (41^st SMW) and it was observed, highest infestation was recorded on 39^th SMW (9.2%). It varied significantly among Bt and non-Bt genotypes throughout the period of observation, being significantly higher in non-Bt genotypes and lower in Bt genotypes. Correlation with abiotic factors was also calculated. It was found that bollworms infestation showed negative significant correlation (r= -0.740**) with minimum temperature and non-significant negative (r= -0.309) with maximum temperature, evening relative humidity (r= -0.434) and with rainfall (r= -0.074). They had positive correlation (r= 0.132) with morning relative humidity.