Cassava (Manihot esculenta Cranzt) is a perennial crop native to tropical America [1,2]. About 70 million people obtain more than 500 cal per day from the crop [3,4]. The crop offers the advantage of a flexible harvesting time, allowing farmers to keep the roots in the ground until needed [5]. In addition, the crop produces reasonably well under growth limiting conditions. In Africa, it is recognized as a famine reserve crop due to its tolerance to drought or infertile soils, and its ability to recover from disease and pest attacks. The area of cassava under unfavorable environments has been continuously increa- sing [6].