Incidence and control of onion fly, Delia antiqua, at some irrigation sites in the Upper East Region of Ghana

Abstract

Studies were conducted between 1994 and 1997 on the incidence, distribution, and control of the onion fly Delia antiqua in northern Ghana. Results showed that the insect is prevalent in most of the onion-growing areas and is capable of causing up to 33 per cent crop damage. It was also established that early transplanting (before mid-January) and transplanting of seedlings 6 weeks after emergence reduced D. antiqua infestation and crop damage. Neem seed powder and aqueous neem seed extract were as effective as Carbofuran for the control of the onion fly. Economic nalysis showed that the neem products were the most cost-effective and had the best returns.


Ghana Jnl agric Sci. Vol.32(2) 1999: 205-211