Maize is one of the most important cereal crops in tropical Africa. In Africa, diets are based primarily on coarse grains (maize, millet, and sorghum) or roots and tubers (cassava, yams and sweet potatoes). Per capita cereal production in Africa has actually fallen during the past 25 years while population growth averaged 2.9% from 1961-1965 to 1984-1988 (CIMMYT 1990). Demand for wheat and rice is increasing through much of the continent, yet climatic and economic factors limit the production of these two crops. At the same time, consumption of millet, sorghum, roots and tubers is declining, even though these crops are suited to local production. In large areas of Eastern and Southern Africa, maize is the principal staple food, produced and consumed by most farming house-holds. While relatively less important in Western and Central Africa, maize still provides a major source of calories, especially in parts of Nigeria, Ghana, Benin, and Cote d'Ivoire. But whatever its present importance, maize clearly has enormous potential as a source of food and feed, because 'Of its high productivity. Improved maize technologies offer the possibility of greatly increasing yields and production.10 pages