Efficacy of bio-rational pesticides for the management of Leucinodes orbonalis Guenee in Rupandehi, Nepal

The field experiment was conducted from March to June of 2017 in field conditions at the Institute of Agriculture and Animal Science (IAAS), Paklihawa Campus, Rupandehi, Nepal to evaluate the efficacy of botanicals, microbial, and chemical insecticide against Leucinodes orbonalis Guenee. We assessed seven treatments including control in randomized complete block design with four replications and two sprays. The treatments evaluated for the management of L. orbonalis were i) Jholmal, 250 ml/l of water ii) Beauveria bassiana (Daman), 4 g/l water iii) Abamectin 5 % (Biotrine), 0.5 ml/l of water iv) Bacillus thuringiensis var. kurstaki (Mahastra), 4 g/l of water v) Emamectin benzoate (Cobra), 0.5 g/l of water vi) Azadirachtin 1500 ppm (Neem Kavach), 5 ml/l of water vii) Control (pure water application). All the treatments applied were found to be superior to the control. The results revealed that the lowest percentage of infested fruit i.e. 57.97% and 34.52% were found at 14 days after the first and second spray of Emamectin benzoate treatment respectively, as well as it was found to be significant over control in both sprays. The marketable yield of plot treated with Emamectin benzoate in eggplant was found to be the highest i.e.7.19 t/ha and 7.13 t/ha which was followed by Neem Kavach with the yield of 6.69 t/ha and 7.06 t/ha and that of control plots was 2.98 t/ha and 2.56 t/ha after first and second spray respectively. Further, our study concluded both marketable yield and Benefit-Cost (BC) ratio of brinjal fruit were the highest under the treatment of Emamectin benzoate followed by Jholmal and Neem Kavach. From this experiment, we concluded that Emamectin benzoate was the most effective treatment for the management of L. orbonalis while Jholmal and Neem Kavach proved to be the best alternative.