author(s)
R Zorempuii and Ashwani Kumar

abstract
The present study was carried out against aphis (Lipaphis erysimi Kalt), entitled “Efficacy of certain chemicals and botanicals on population density of aphid, Lipaphis erysimi (Kaltenbach) on cabbage (Brassica oleracea L.) at different destructive index” cultivar i.e. Golden acer during Rabi season November 2018 to March 2019 at Agriculture research farm, SHUATS, Prayagraj. The insecticides were used per recommended doses along with an untreated control. Each insecticides were sprayed twice at 15 days interval. Spraying was applied as soon as the pest population reached the ETL. The pest count per plant was taken 1 day before spray and 3, 7, 11 and 14 days after spray. The insecticide tested significantly reduced the pest population compare to control. The highest percent reduction of aphid in chemical insecticides was observed in Malathion 50 Ec (68.68) followed by Dimethoate 30 Ec (65.85) and among the botanicals extract highest pest percent reduction is observed in MECH 333 (64.69) followed by NSKE 5% (61.28). And the highest yield was observed in Malathion 50 Ec (66.66 t/ha) followed by Dimethoate 30 Ec (60.41 t/ha). Thus, Malathion 50 Ec (1.80) have the best benefit cost ratio followed by Dimethoate 30 Ec (1.63) having the second best benefit cost ratio.