In West Africa, groundnut is a very important grain legume crop for smallholder farmers, especially women, it is a major cash crop for many households; it contributes to soil fertility with biological nitrogen fixation; and its haulm is a good livestock feed. Despite its importance, the productivity of the crop remains low with yield of around 1t ha-1 compared with global average of 1.5t ha-1 and over 3t ha-1 in USA and China.