Mark Rosegrant of the International Food Policy Research Institute (IFPRI) calculates that crops that will yield 25 per cent more food would boost African food production more than doubling irrigation would. It might also be easier. "We have tremendous options to enhance yields," says Hans Braun, head of wheat at the International Maize and Wheat Improvement Center.
Last week the world's wheat scientists launched a consortium to raise wheat yield by genetically re-engineering the crop's photosynthesis, no less. "It is inefficient compared with some plants," says Braun. "Improvements are feasible, and will dramatically increase water efficiency, heat tolerance and yield." They plan to equip wheat with more efficient variants of the key photosynthetic enzyme rubisco, and with suites of genes to convert it from the C3 photosynthetic system to the C4 system found in maize, which fixes more carbon per unit of light. Meanwhile, CGIAR's International Rice Research Institute in the Philippines is developing C4 rice.
Braun says the key is money. The yields of new varieties of maize are climbing twice as fast as yields of rice and wheat. This is because maize is bred mainly by private companies, which invest $1.5 billion a year in it. Wheat and rice breeding, by contrast, is done mostly in government labs. Wheat gets only about $350 million a year. Apart from Chinese hybrid rice varieties, rice yields have been stagnant for years.