Efficacy of Neem in combination with cow urine against mustard aphid and its effect on coccinellid predators

Abstract

Aphid, Lipaphis erysimi Kalt. is the most serious pest of mustard crop in North India causing yield losses up to 93% (Verma & Singh, 1987). The use of insecticides, viz. Phosphamidon, Dimethoate, Methyl demeton, etc. have been recommended for the effective control of this pest (Upadhyay & Agrawal, 1993; Sinha et al, 1997; Prasad, 1997). Abstract Neem leaf extracts (NLE) and neem kernel extracts (NKE) in cow urine, neem oil, insecticides Phosphamidon, Dimethoate and their combinations were evaluated against the mustard aphid, Lipaphis erysimi Kalt. along with their impact on the activity of predator, coccinellid beetles. The treatments significantly reduced incidence of mustard aphid and increased the grain yield of mustard. Combination treatments of Dimethoate 0.03% either with NKE 3% or NLE 3% followed by Dimethoate 0.045% and Phosphamidon 0.04% were most effective in reducing the aphid incidence. Grain yield was maximum in Phosphamidon 0.04% followed by neem oil 1% + Dimethoate 0.03% and NKE 3%. Net profit was also maximum in phosphamidon (Rs. 9246/ha) and NKE 3% (Rs. 5938/ha). Whereas, incremental cost benefit ratio was highest in NKE 2% (15.5) and NKE 3% (15.1). The results conclude that the incidence of mustard aphid can be safely and successfully managed by adopting 3 or 4 foliar sprays of neem kernel extract (in cow urine) 3% either alone or in combination with reduced dose of Dimethoate 0.03%.