author(s)
TR Manjula, GS Kannan and P Sivasubramanian

abstract
Pseudomonas fluorescens was evaluated in 2013-14 and 2014 -15 cotton growing season against the sucking pest complex infested in Bt cotton, aphid, Aphis gossypii, leafhopper, Amrasca devastans and thrips, Thrips tabaci. Reduction in the infestation and pest population was determined after three successive sprays with 15 days interval. The effect of P. fluorescens on seed cotton yield was considered and compared with the untreated check. Side effect on natural enemies, ladybird beetle, Menochilus sexmaculatus, green lacewing, Chrysoperla carnea, hover fly, Syrpus sp. and spiders population were also considered. Data obtained from the present study revealed that the soil and foliar application of P. fluorescens was found to be effective in reducing the aphid, leafhopper and thrips population more than 58, 77 and 40 % respectively. Imidacloprid was found to be the most effective chemical treatment which records the least population of aphid, 13.86/3 leaves, leafhopper, 2.90/3 leaves and thrips, 13.80/ 3 leaves and was followed by soil and foliar application of P. fluorescens, 17.98, 3.63 and 19.45/3 leaves of aphid, leafhopper and thrips respectively. The imidacloprid treatment was associated with the greatest reduction in the population of the natural enemies. In contrast P. fluorescens treatments had the minimum side effect on the natural enemies. Significantly higher seed cotton yield of 27.64q/ha was harvested with soil and foliar application of P. fluorescens plots.