The USDA bumped up the U.S. corn yield by 1.7 bushels per acre in the the September supply and demand report for a national average of 176.3 bushels per acre. 

Harvested acres increased 600,000 acres from August, and the combination of these factors was enough to give the United States a 15 billion bushel corn crop. 

Old crop demand was lowered by 70 million bushels, which further increased the new crop corn supply. 

New crop corn demand increased 75...