ABSTRACT

Cassava (Manihot esculenta Crantz) is a woody perennial shrub grown for its starchy tuberous roots.Cassava belongs to the family,Euphorbiaceae which also contains other commercially important plants like castor bean (Ricinus communis L.) and rubber (Havea brazilienesis L.). The genus Manihot comprises 98 species and all the species studied so far have chromosome number of 2n=36  1973; Nassar 1978; Bai, 1987),which contain lacitifers and produce latex. Cassava is its wild progenitors are not known, the regions of its domestication are disputed (Rogers the most widely consumed root crop in the tropics (Nweke et al., 1994; Henry and Hershey, 1995). It is a major food source for more than 500 million people in Africa, Kunchai, 1991). native to tropical South America, and is one of the oldest cultivated crops (Jennings 1976) with possibly two centers of origin. Since cassava does not exist in the wild and and Appan, 1973; Rogers and Flemming, 1973: Nassar, 1978). From Latin America, cassava was introduced to Africa in the 16th century and today it is cultivated worldwide in more than 80 countries between 30° South and 30° North of the equator. Cassava is Latin America and Asia. It is mainly cultivated for its starchy roots with a world production estimated at 228 million'metric tons, harvested from 18.4 million hectares, with Nigeria, Thailand, and Brazil being the largest producers (FAO, 2002). The storage roots are the basic component of the carbohydrate diet and the leaves are consumed as the preferred green vegetable in many parts of Africa, providing protein, minerals and vitamins (Hahn, 1989). Approximately 71% of world cassava production is utilised for human consumption, while the rest is for animal feed and industrial uses (Sarma and