Wheat for September delivery fell 5.5 cents to $4.76 a bushel, while December corn lost 4.5 cents to $3.275 a bushel and November soybeans dropped 18.75 cents to $10 a bushel. Oats for December delivery fell 2 cents to $2.13 a bushel.
Meanwhile, beef and pork futures also fell on the Chicago Mercantile Exchange.
October live cattle slipped 0.2 cent to 88 cents a pound; October feeder cattle edged down 0.55 cent to 99.52 cents a pound; October lean hogs fell 0.4 cent to 45 cents a pound; and August pork bellies lost 2 cents to 38.5 cents a pound.