Econet boss Strive Masiyiwa who made his fortune from mobile telephones believes that it is agriculture development that will drive the African economy. But in the United States, the most developed nation in the world the 320 million people there are fed by 1 percent who farm. In Africa some 65 percent of the population, which now stands at 1.1 billion, farms. While Americans spend less than 10 percent of their disposable income on food, Africans must devote the vast majority of their income to food. It is common for US farmers to get yields of 200 bushels of corn per acre; in Africa 20 bushels an acre is common. This translates to 5 tonnes per acre and half a tone per acre, respectively. One acre is 0.4 hectare or one hectare is 2.5 acres.