author(s)
RL Kalasariya, BB Katariya and KD Parmar

abstract
Investigation was conducted at the College Farm, College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat to study the effect of weather parameters on population fluctuation of leaf webber and role of abiotic factors influencing their population for consecutive two years during rabi season of 2012-13 and 2013-14. The results revealed that the direct effect of morning and evening relative humidity on larval population of leaf webber was negative and very high (r = -7.3552 and r = -3.2490, respectively) while it was positive and very high (r = 12.6507) by mean relative humidity. The direct effect of maximum temperature and bright sunshine hours were positive and very high (r = 2.4703 and r = 2.0583, respectively) while minimum temperature exhibited negatively high direct effect (r = -1.003) on larval population of leaf webber. Residual value indicated that all abiotic factors had a total combined effect of 41.77 present on population build-up of mustard leaf webber. It indicated that 58.23 per cent was through other unknown factors existing in the ecosystem during both seasons.