* Hot weather expected to hit supplies from big exporters
* Lack of rain a concern in key development phase for soybeans
CHICAGO, Aug 25 (Reuters) - Chicago soybean and corn futures rose on Friday, bolstered by extreme heat and mixed results on the final day of a Midwest crop tour.
Wheat fell as global supplies remain plentiful, though signs of concern have crept into some key growing regions.
The most active soybean contract on the Chicago Board of Trade (CBOT) added 13-1/4 cents to $13.85 a bushel by 11:34 a.m. (1634 GMT).
For the week, soybeans are set to rise 2%, the second consecutive weekly gain.
CBOT corn edged up 1/2 cent to $4.88-3/4 a bushel, poised for a weekly decline of less than 1%.
CBOT wheat lost 9-3/4 to $6.22 a bushel, headed toward a 2.5% weekly loss.
While soybean samples taken in Iowa exceeded three-year averages during the Pro Farmer Crop Tour, Minnesota samples produced the lowest pod counts since 2019.
Corn yield prospects in both Iowa and Minnesota fell below three-year averages.
Pro Farmer will release national corn and soybean estimates after the market closes on Friday.
Soybeans were further boosted by a sale of 121,000 metric tons of soybeans to China for delivery in the 2023/24 marketing year, according to the U.S. Agriculture Department.
"Beans are 60 cents off the lows from Wednesday," said Jeff French, owner of AgHedgers. "It's a very good pre-harvest rally."
French said the rally could incentivize farmers to sell soybeans, opting to store corn to wait for higher prices.
"Selling $13.50 beans cash off the combine is a hell of a lot better than selling, $4.40 corn," he said.
Wheat felt pressure from weak export demand and a strong U.S. dollar.
The U.S. dollar edged up against a basket of currencies on Friday, as the Federal Reserve considers additional interest rates hikes.
"Chicago soft wheat is struggling to find the demand that it needs," said Arlan Suderman, chief commodities economist at StoneX.
Argentina's wheat crop needs precipitation in the coming days across key farmland to stave off a hit to yields, a weekly report from the Buenos Aires Grains Exchange showed on Thursday.
Prolonged heat across many Ukrainian regions has dried the upper soil level, creating unfavorable conditions for winter grain sowing, analysts at APK-Inform quoted state weather forecasters as saying on Thursday.
The European Commission further reduced its outlook for European Union production of major cereal and oilseed crops this season, with maize given the sharpest reduction. (Reporting by Christopher Walljasper; additional reporting by Naveen Thukral; additional reporting by Peter Hobson; Editing by Susan Fenton)
