I like the comment re: local varieties. These are the ones to be developed and cultured and irrigation. The choice of crops to irrigate should also be to local needs and desires with local farmers making the decisions rather than an Ex-pat expert from Asia. I've seen a cow pasture turned into one of the largest horticultural specialty farms in Zambia. They are exporting green maze and cherry tomatoes into Europe providing local employment for these labor intensive crops and foreign exchange earnings to buy machinery, fertilizer and pesticide to grow more food crops. The food crop of choice in East Africa is Maze not rice. The transport and storage of these crops is more important than irrigation. For a land locked country that needs to raise foreign exchange, the best export crop to grow would be tobacco. When will the World Bank Support the development of tobacco production? LOL. Making bad choices for poor countries is just not the way to go. Africa is the largest populated Continent in the world. Speaking in generalities should be avoided. One size does not fit all.