Economic Evaluation of Insect Pests Management in Cashew Productionin Mtwara, Tanzania

Cashew production is severely constrained by sucking insect pests such as coconut bugs, cashew mosquito bugs and thrips. They damage flushing foliar, floral shoots and developing nuts. Weaver ants (Oecophyllalonginoda) have for long been considered as effective biological control agents against pests. Before changing from one production method to another, farmers need to consider costs and incomes resulting from the change. This paper evaluated economic benefits of managing cashew insects using weaver ant, Karate and control. The experiment was conducted in a Randomized Complete Block Design with four replications in, Mtwara during 2012-13 and 2013-14. The statistically significant treatments were subjected to economic analysis using the partial budget and MRR. Discounted financial indicators (NPV, BCR and IRR) were used. The study revealed that damage caused by each pest was significantly lower on trees with weaver ants and in the plots treated with Karate® than was the case on the control trees. There was no significant difference in the damage between O. longinoda and Karate® treated trees suggesting that the two treatments are equally effective. The difference in the damage levels was directly reflected in the mean cashew yield. Switching to weaver ants was feasible due topositive net change in benefits. MRR was highest forweaver ants at 235% in 2012/13 and 405% in 2013/14 seasons. Weaver ant indicated highest NPV (TZS 32 640), BCR (2.5:1) and IRR (57%). The use of weaver ants was economically feasible management strategy to be adopted by farmers and was recommended