Pest control for cassava and sweet potato.

The prevailing socioeconomic conditions of the smaliholder farmer in Africa militate against the widespread use of insecticides not only because of the costs of the chemicals but because of the long-term side-effects from their misuse. Thus, other means of pest control must be sought. Agricultural researchers must concentrate on building-in host-plant resistance, identifying and introducing natural enemies of the offending pests, and developing agronom ic practices that discourage the buildup and spread of the pests. Progress along these lines for two important staple root crops - cassava and sweet potatoes - in Africa has been consider able over the last 10 years; the focus and accomplishments of work to date are reviewed in this paper.