Cassava can grow in areas with a little than 500 mm annual rainfall and can survive dry periods of 5-6 months. It is therefore widely distributed in the tropical and subtropical ecosystem of Africa with increasing cultivation under unfavorable environments due to its many advantages over other crops. Cassava is known to adapt to conditions of soil water shortage through various mechanisms, such as shedding leaves, closing stomata, osmotic adjustment, increasing root length and decreasing the leaf area Cassava leaves remain photosynthetically active under prolonged drought, although at a reduced rate and they are capable of partially recovering their photosynthetic capacity once released from stress [6].