The price of corn is falling further as a mix of sunshine, rain and moderate temperatures increases the likelihood of a record crop this year.
Corn for delivery in September dropped 3.75 cents, or 1 percent, to $3.68 a bushel on Tuesday.
The price of corn has slumped 30 percent since the end of April as the favorable weather has boosted the outlook for this year's crop.
Wheat and soybeans also fell.
In metals trading, gold, platinum and palladium edged lower. Silver was flat and copper made a small gain.
The price of oil fell for a third day, dropping 17 cents, or 0.2 percent, to $104.42 a barrel.