CARROLL COUNTY, Ill. (Reuters) - Corn farmers in west-central Illinois are facing potentially smaller corn yields this fall in what has been a challenging growing season after extreme weather and heavy rains delayed plantings across much of the U.S. Midwest, scouts on an annual tour said on Wednesday.

FILE PHOTO: Corn grows in a field outside Wyanet, Illinois, U.S., July 6, 2018. REUTERS/Daniel Acker

Many of the soy fields surveyed in Illinois on the third day of the Pro Farmer Midwest Crop Tour were also behind their normal growing schedule, as they were in parts of Indiana and Ohio, with fields of short soybean plants an indication of the late planting.

But the corn crop improved significantly the further west the scouts traveled despite the later-than-normal plantings, and there were few signs of unplanted fields.

“There were some strong yields and some clunkers, which will pull down that higher average a bit,” said Brian Grete, director of the tour’s eastern half. “This was on a better area than what we’d seen previously and it is a better crop - and it should be, given where we are.”

Soybean pod counts continued to be hit and miss, but soybean fields in this stretch may not need as much time as other parts of the state.

“It’s all going to depend on what that weather looks like in September,” Grete said.

Chicago Board of Trade soybean futures SX9 closed higher on Wednesday on technical buying and uncertainty about U.S. yield prospects.

The farm community and commodity traders are closely watching the four-day crop tour after grain futures prices plunged in the wake of a U.S. Department of Agriculture report earlier this month that forecast a larger-than-expected corn crop.

On Wednesday, corn yield potential averaged 175.56 bushels per acre (bpa) through eight stops in the Illinois counties of McLean, Tazwell, Peoria, Knox, Stark and Henry.

That is down from last year’s crop tour average in those areas of 201.45 bpa and the three-year tour average of 194.77 bpa.

The tour does not estimate soybean yield potential, but instead calculates the number of soy pods in a 3-foot-by-3-foot square.

In those Illinois counties, soybeans averaged 1154.42 pods, down from 1307.06 pods last year and the three-year average of 1260.09 pods.

But the findings this year have been highly variable - more than normal, scouts said.

A second leg that scouted six counties in Illinois - Bureau, Carroll, Marshall, Putnam, Woodford and Whiteside counties - with 10 stops found soybeans averaged 688.76 pods. That was below last year’s 1257.83 pods and the three-year average of 1246.61 pods.

Scouts on the route also found corn yield potential averages of 150.1 bpa. That is down from last year’s 194.31 bpa and from the three-year average of 191.60 bpa.

The eastern leg of the tour began in Columbus, Ohio, and the western leg in Sioux Falls, South Dakota.

Scouts from the different routes are set to meet in Rochester, Minnesota, on Thursday for the final tour summary. The trade publication Pro Farmer, which organizes the annual tour, will crunch the collected data and release its U.S. crop production and yield forecasts on Friday.