Impact of Abiotic Factors on Incidence of Fruit and Shoot Infestation of Spotted Bollworms Earias spp. on Okra (Abelmoschus esculentus L.)

Role of weather factors on the fluctuations of fruit and shoot infestation by Earias spp. on three comparatively more susceptible (Parbani Karanti, Pusa sawani, Ikra-1), three moderately susceptible (PMS-beauty, Ikra anamika, Lakshami-24) and three comparatively least susceptible (Diksa, Sabz ari, Super Star) genotypes of okra was studied under field conditions at Post Graduate Agriculture Research Station, University of Agriculture Faisalabad, during 2006 and 2007. Maximum, minimum and average temperatures showed a positive effect; whereas, the relative humidity and rainfall exerted a negative effect on the fruit infestation, separately as well as on cumulative basis. The shoot infestation of okra was found to be positively correlated with maximum and average temperatures and negatively correlated with the relative humidity and rainfall on the basis of an average for both the years of studies. Multiple Linear Regression Models revealed that the maximum temperature was the most important factor, which had maximum impact on fruit and shoot infestation, i.e., 60.50 and 53.20% for an average of both the study years, respectively. The impact of all the factors on an average of both the study years when computed together was found to be 67 and 55.50%, for fruit and shoot infestation, respectively.