Corn plants are seen in a drought-stricken farm field near Evansville, Indiana, July 18, 2012. Oppressive heat and a worsening drought in the U.S. Midwest pushed grain prices near or past records on Wednesday as crops wilted, cities baked and concerns grew about food and fuel price inflation in the world's top food exporter. REUTERS/John Sommers II (UNITED STATES - Tags: AGRICULTURE ENVIRONMENT BUSINESS)