Field efficacy ofPseudomonas fluorescens against the cotton leaf hopper, Amrasca devastansDistant (Hemiptera: Aphididae) in Bt and non Bt cotton

An experiment was conducted to evaluate the efficacy of Pseudomonas fluorescens against leafhopper of Bt cotton and non Bt cotton in two location of Vanavarayar Institute of Agriculture, Pollachi and South Indian Millers Association, Udumelpet. Seven treatments i.e. foliar application of P. fluorescens @1%, soil application of P. fluorescens 2.5 kg/ha, soil and foliar application of P. fluorescens @1%, foliar application of P. fluorescens @1% and Beauveria basianna @ 1%, foliar application of Beauveria basianna @ 1%, imidacloprid 200 SL @ 200ml/ha and Untreated check were evaluated. Among the bio inoculants treatment the maximum per cent reduction in leafhopper population with a mean of 71.00; 83.45; 85.01 and 63.28; 82.32; 91.58 at 1 st , 2 nd and 3 rd spray after application in both the locations respectively in Bt cotton during 2013-14. The similar trend was also observed in non Bt cotton. During 2014-15, the maximum per cent reduction in leafhopper population recorded among the bio inoculants treatment, the soil and foliar application of P. fluorescens @1% in two locations and both bt and non Bt cotton. The highest mean seed cotton yield was obtained in soil and foliar application of P. fluorescens @1% in two locations, and both years of 2013-14 and 2014-15.