Assessing the potential impact of biological control of Plutella xylostella (diamondback moth) in cabbage production in Kenya

The project costs amount to a net present value of US$ 1.2 million. Based on an annual cabbage production of 256,524 tons, a cabbage price of US$ 66.3/ton, a 30% abatement of yield losses, a 7.9% reduction in cost of production, a supply and a demand elasticity of 0.9 and −1.4 respectively, and an annual increase of consumption of 2.6%, the economic surplus produced by the release of the parasitoid was estimated at US$ 28.3 million for 25 years. Consumers were estimated to get 58% of the benefit and producers 42%. The benefit-cost ratio was estimated at 24:1, with an internal rate of return of 86%, indicating a high return to the investment.