Mail and Guardian 1 June 2011.

This year, 40% of the United States’s corn crop will go into car engines rather than stomachs. Add the fact that the US is both the world’s largest producer of corn and the largest exporter, and that 10 years ago only 7% of its corn went to ethanol production, and you start to see why the sudden enthusiasm for biofuels among oil importers has had such a marked impact on food prices. ..

http://mg.co.za/article/2011-06-01-global-food-crisis-counting-the-real-cost-of-biofuels/