Cassava (Manihot esculentum) is the only cultivated food crop species of its genus (Fauquet 1990). It has many names including mogo (Africa), cassava, yucca and tapioca (wikipedia). Cassava is a woody perennial shrub that is never grown, as a crop, beyond 30° N and 30° S of the equator (Cock 1985). The crop is much more limited in flow rate by precipitation rather than temperature. The cultivated cassava plant can grow to 5 to 12 feet, but in abandoned fields it can grow to 18 feet (Jones 1959). The leaves are large and palmate, growing from 3 to 11 lobes, varying depending on the region of attachment (Nartey 1978). They only grow towards the ends of the branches; the positions of previous leaves are marked by a series of alternating nodes along the branch (Jones 1959). As the plant grows, the main stem forks, usually into three branches, and the smaller branches in turn divide in a similar way (Cock 1985). The stems are woody and fragile, varying in diameter with age, averaging approximately 3 to 6 cm (Nartey 1978). The cassava plant is grown primarily for its tuberous starchy root. The crop is a major source of calories, after corn, sugar (cane and beetroot) and rice, for over 400 million people in tropical countries in Asia, Latin America and Africa (El-Sharkway 1993). Cassava provides 38.7%, 11.7%, and 6.7% of total calorie intake in Africa, Latin America, and the Far East, respectively (Nartey 1978). Cassava has a high percentage of dry weight, between 30% and 40%, and starch and sugar constitute 90% of the dry matter (Cock 1958). Cassava is relatively rich in calcium and ascorbic acid (vitamin C) and contains significant amounts of thiamine, riboflavin, and niacin (Jones 1959). The diets, which consist mainly of cassava, may be left... middle of paper... by the Portuguese traffics migrating between Brazil and the West African coast. Evidence reveals that cassava was introduced into the Congo as early as 1588. The Portuguese brought cassava from Brazil to their trading posts along the coast from present-day Ghana to Somalia (Jones 1959). Through multiple sites of introduction, cassava rapidly spread to Angola, Zaire, Congo, Gabon and Cameroon. Cassava was independently introduced to East Africa and Madagascar by the mid-eighteenth century. One hundred years later, in Africa, although the exact location of origin is still in dispute, there is no question of cassava's importance in the daily calorie intake of many tropical nations. It is clear that cassava has been introduced to Africa, India, Southeast Asian countries and the Pacific Islands, all originating from Brazil (Thampan 1979).