Global corn production estimates have dropped, with the latest number sitting at 838 million metric tons for the 2012–2013 harvest year, down 3 percent from the 864 million metric tons forecast on July 26 and below 2011–2012's output of 875 million metric tons, according to the International Grains Council. The new number reflects the continuing effects the U.S. drought is having on production in the Northern hemisphere, stressing crops and raising prices.

Corn prices have increased 64 percent since mid-June on the Chicago Board of Trade, hitting a record $8.49 per bushel on Aug. 10. This, in turn, raised global food costs by 6.2 percent in July, according to the United Nations, the most since November 2009.

Corn production in the U.S. may total 275 million metric tons, down from the 300 million metric tons estimated in July, said the International Grains Council. The U.S. Department of Agriculture has predicted a U.S. harvest of 273.8 million metric tons, the smallest in six years, and global production of 849 million metric tons.