Wheat futures are sharply lower as investors worry about a slowdown in purchases and new supplies coming on the market from Argentina.
The actively traded May contract for wheat fell 16 cents, or 3 percent, to $5.89 a bushel Thursday.
Wheat had been rising over the past several weeks as traders anticipated that transportation problems in Canada would hinder that country's crop from coming to market.
Traders also worried that a large purchase of wheat from Egypt announced Thursday didn't include any from the U.S., according to Todd Hultman of DTN in Omaha, Neb.
May corn fell 6 cents, or 1 percent, to $4.54 a bushel and May soybeans edged down 7 cents, or 0.5 percent, to $13.90 a bushel.
Energy futures closed slightly lower. Metals futures were mostly higher.