Efficacy of plant leaf extracts against mustard aphid Lipaphis erysimi (Kalt.) under field condition

The bio-efficacy of five plant leaf extracts were tested in Morang-2 variety of Rapeseed against Mustard aphid (Lipaphis erysimi Kalt.) during November to March, 2016/17 at research field of Institute of Agriculture and Animal Science (IAAS), Lamjung Campus, Lamjung, Nepal. The plant leaf extracts were prepared by decomposing chopped leaves of Neem, Bakaino, Hattibar, Khirro, and Bojho in cow urine for one month period. Total five extracts were prepared, one by mixing all the leaf while remaining four extracts were prepared excluding one ingredient in each mixture but keeping Tobacco and Bojho in all five extracts. The experiment was laid out in Randomized Completely Block Design using five botanical extracts, chemical (Cypermethrin 10% EC) and control which were replicated thrice. The Rapeseed plant was sprayed with prepared extracts at 30 days after sowing (DAS), 45 DAS and 60 DAS and aphid number counted after 5, 10 and 15 days of each spray from 10 cm apical shoot. The greatest reduction of aphid population was found in chemical followed by complete mixture treated plots but their reduction was not statistically different. While control and plant extracts of without Neem treated plots had resulted less reduction in the number of aphid. Grain yield was also found highest (1436.75 kg/ha) in complete mixture treated plots indicating complete mixture of plant extracts might be the best alternative for aphid management in Rapeseed. It is concluded that all the plant extracts showed insecticidal properties against aphid in rapeseed crop and successfully be integrated, as a part of Integrated Pest Management.