CHICAGO  Commodity prices went wild on Wednesday, with the price of corn shooting through the $7 barrier for the first time, soybeans and wheat moving up sharply and oil jumping more than $5 a barrel.

Corn prices, which have been hitting new highs for a week, are reacting to six weeks of heavy rains and cool weather in the Midwest. That prevented planting in some areas, leading some farmers to abandon the crop in the last few days. It is still raining.

The bad weather comes as supplies of corn, wheat and other staples are already tight thanks to soaring global demand.

The higher commodity prices are likely to add to a worldwide inflationary picture that seems to worsen by the day. Prices of many grocery items in the United States have been rising briskly, with some goods like eggs and milk  produced from animals fed with corn  up by 13 to 30 percent in the past year.