Groundnut (Arachis hypogaea L.), also known as peanut, is cultivated in the semiarid tropical and subtropical regions of nearly 100 countries in six continents between 40° N and S of the equator. In Southern and Eastern Africa, peanut is grown at an altitude of over 1500 m, with a rainfall of 300-1000 mm. In Western and Central Africa, peanut is cultivated in semi-arid areas. There, a growing season of 75-150 days with an annual rainfall of 300-1200 mm is required.