ABSTRACT
Maize-growing areas with environments classified as tropical cover 36.7 million hectares, 45 percent of the total maize area in the developing world and are found in all developing country regions, except North Africa and the Middle East. Maize environments in developing countries can be grouped into four major classifications: tropical, subtropical, temperate, and highland. Moving from lowland to highland elevations, maize environments change from tropical to subtropical to cool highland elevations. Nearly 70 percent of the tropical maize area—25 million hectares—usually has sufficient moisture for maize production. Also, when farm sizes are larger and maize production is mechanized and more agricultural chemicals are applied, the crop is grown as a solid stand, usually in rotation with other crops. Subtropical environments are a function of altitude and latitude. About 90 percent of the maize area in subtropical environments is rainfed.
