An increase in fuel ethanol inventories is pushing the price of corn down to a five-month low.
Corn for March delivery fell 17 cents to finish at $7.03 a bushel Wednesday. That's the lowest since July 6.
The Energy Department said fuel ethanol supplies rose 20.8 million barrels last week, 18 percent more than a year ago.
Analysts said the increase in stockpiles could indicate slower demand in the months ahead.
Other commodities ended mixed as U.S. budget negotiations appeared to hit a wall less than two weeks before tax hikes and government spending cuts are set to take effect.
In other trading, prices for oil, wholesale gasoline and orange juice rose. Gold, industrial metals, wheat and soybeans fell.