ABSTRACT
African yam bean is native to Africa. The centre of diversity spreads from the west to the eastern and southern parts of Africa. The genus Sphenostylis, comprising seven species, occurs in dry forests and in open or forested savannas in tropical and southern Africa. African yam bean is grown primarily for its dry seeds and tubers. African yam bean, a perennial climbing bush, is usually grown as an annual. African yam bean, being a crop of tropical and subtropical regions, needs a warm and dry climate for its growth and development. The crop can be cultivated successfully on a wide range of soils, even in poor soils, but it thrives best on deep loose sandy loam or loam soils with good organic matter content and proper drainage facilities. African yam bean is generally sown during the start of the rainy season between May and July. The seed rate varies according to the growing season, growing region and cultivation system.
