Farmers harvesting their corn may find less of the crop than anticipated as the state office of the National Agricultural Statistics Service lowered corn yield estimates for Illinois, citing dry and hot weather in late summer.

The Illinois estimate made earlier this month is now 161 bushels an acre, down from 170 in August, Peoria's Journal Star reported (http://bit.ly/n1v7aK ) on Tuesday.

"The yield is down as a result of the exceptionally hot weather experienced while much of the crop was in pollination stage," the field report noted. Meanwhile, Monday's state crop report shows that the Illinois corn harvest is 22 percent complete. Last year at this time it was 54 percent finished.

Corn roots didn't penetrate normally because of wet spring weather, said Peoria County Farm Bureau manager Patrick Kirchhofer. That combined with extreme heat and dry weather meant the plants didn't have a strong anchor, he said.

Kirchhofer said farmers won't know exactly what's in their fields until they're harvesting.

"Fields will have holes," he said. "You don't see them until you open things up."

Tazewell County Farm Bureau manager Doug Godke said "some people are a little nervous" as farmers begin to harvest. Godke said early indications are the corn crop "won't be as good as last year."

Farmer Mike Hoeft of Delavan reports uneven results.

"You can't have 98-degree weather and no rain and expect good results. The corn crop actually went backwards this year. It lost some weight while it was out in the field," Hoeft said.

Copyright 2011 The Associated Press.