Chicago grain futures weaken ahead of USDA crop report

Farmers grow corn, soybeans, and wheat, and their prices change every day on big food markets.

On Tuesday, prices for these grains fell in Chicago.

That's because traders were getting ready for a big report from the U.S. Department of Agriculture on Wednesday.

The report will say how much corn and soybeans farmers are expected to grow this year.

Traders think the report will show slightly less corn per field, but they already had a pretty good idea of that.

There has also been rain and cooler weather for the crops, which helps plants grow.

Good weather usually means more food, and more food means lower prices.

Wheat prices also dropped even though some ships in the Black Sea had been having trouble, because people think the shipping problems won't last forever.

Overall, the market went down because traders didn't have exciting new news to push prices up.

Lower grain prices can be good for people who buy food.