* Pro Farmer tour scouts fields in Illinois
* Rains set to hit dry areas of U.S. Corn Belt
* Concerns ease about Ukraine grain supplies (Updates with U.S. trading, analyst comments, changes dateline/byline)
By Tom Polansek
CHICAGO, Aug 20 (Reuters) – U.S. grain futures fell on Wednesday as a closely watched crop tour estimated large U.S. corn and soybean yields in key states and weather forecasts indicated rains would give crops a further boost.
Wheat slid as concerns eased about the risk of reduced supplies from Ukraine, a leading grain exporter.
Traders focused on the Pro Farmer Midwest Crop Tour, which entered its third day on Wednesday with participants surveying fields in Illinois.
Tour results from the state “should confirm expectations for record corn yield,” said Rich Feltes, vice president of research for RJ O’Brien. Illinois has been described by analysts as the garden spot of the Midwest because of its healthy-looking crops.
Chicago Board of Trade December corn sank 1.7 percent to $3.66 a bushel by 12:05 p.m. CDT (1705 GMT). November soybeans lost 1.2 percent to $10.39-3/4 a bushel, having slid 0.5 percent on Tuesday. December wheat tumbled 2.4 percent to $5.45-1/4 a bushel.
Markets felt pressure from expectations for favourable rains to hit corn and soy crops before harvesting begins in the Midwest in a few weeks. Dry areas of Indiana, southern Minnesota, northern Iowa, Ohio and Kentucky are projected to receive moisture in the next five days, Feltes said.
The Pro Farmer tour projected Indiana’s corn yield at a record-high 185.03 bushels per acre, above the three-year tour average of 141.24. The tour pegged Nebraska’s corn yield at 163.77 bushels per acre, above the tour’s three-year average of 146.81.
“Corn futures are struggling with big yield numbers from the Pro Farmer tour,” said Kayla Burkhart, broker for CHS SunPrairie in North Dakota.
“Beneficial rains fell to corn and soybean growing areas overnight and more is in the forecast, giving the row crops more reason to trade lower.”
U.S. wheat weakened after edging up 0.8 percent on Tuesday on concerns the conflict in Ukraine could reduce the country’s wheat export supplies. Attention on Wednesday turned back to the generally plentiful global supply outlook.
Germany’s leading grain trader, ADM Germany, said it had maintained its forecast of a larger German 2014 wheat crop but slightly increased its rapeseed crop forecast.
German farmers’ association DBV raised its estimated for the country’s winter wheat harvest from last month.
Prices at 12:04 p.m. CDT (1704 GMT) LAST NET PCT YTD CHG CHG CHG CBOT corn 366.00 -6.25 -1.7% -13.3% CBOT soy 1039.75 -13.00 -1.2% -20.8% CBOT meal 401.20 1.40 0.4% -8.3% CBOT soyoil 32.92 0.26 0.8% -15.2% CBOT wheat 546.00 -12.50 -2.2% -9.8% (Additional reporting from Michael Hogan in Hamburg and Naveen Thukral in Singapore; Editing by Michael Urquhart and Gunna Dickson)