Wheat is falling for the third consecutive week as traders factor in the prospect of cooler, wetter weather in coming months that will help crops.
The price of wheat for delivery in July dropped 5.25 cents, or 0.8 percent, to $6.28 a bushel. Wheat has fallen 3.9 percent this week and is down 13 percent in the last three weeks.
Wheat is also falling as traders become less concerned that the tensions in Ukraine will escalate to such an extent that they disrupt the nation's export of the grain.
Corn and soybeans also fell on Friday.
Most metals fell, led by a drop in silver futures. Gold, platinum and copper prices also declined. Palladium edged higher.
In energy trading, the price of oil fell 87 cents to $102.71 a barrel.