Among the world’s cereal crops, maize ranks second to wheat in production, with milled rice third. However, among the developing economies, maize ranks first in Latin America and Africa but third after rice and wheat in Asia. Worldwide, maize is the most widely grown cereal crop. Seventy countries, including 53 developing countries, plant maize on more than 100,000 hectares. The far-reaching distribution of maize production is an indication of its excellent capacity to adapt to many environments (Fig. 1.1). Maize is grown at latitudes varying from the equator to slightly above 50° north and south, from sea level to over 3,000 meters elevation, under heavy rainfall and in semi-arid conditions, in cool and very hot climates, and with growing cycles ranging from 3 to 13 months.