* CBOT wheat closes day lower on choppy trade
* Corn, soy post 1st weekly loss in 4, eyes on U.S. planting (Updates with closing prices, weekly trends)
By P.J. Huffstutter
CHICAGO, June 7 (Reuters) - Chicago Board of Trade wheat futures notched a fourth weekly gain on Friday - even after closing the day down 1.27% - as lack of rain in Russia raised concerns over reduced yields in the world’s top exporter of the grain.
Support also came from fears of production losses in Australia, Ukraine and Canada caused by dry weather, traders said, while markets watched how the winter wheat crop in the southern U.S. Plains and Midwest coped with recent wet weather.
Corn futures slipped after Thursday’s surprise rebound on poor export sales. Soybean futures also fell on Friday, under pressure from wheat and corn, traders said.
Corn and soybeans posted weekly losses after rallying for the last three weeks with farmers in the western corn belt expected to get a window of dry weather to seed crops.
Traders awaited the first U.S. crop condition ratings for the 2019 corn crop, which are expected from the U.S. Department of Agriculture on Monday.
“It’s the beginning of the great yield debate,” said Don Roose, president of U.S. Commodities in West Des Moines, Iowa. “The debate will be figuring out how big the production losses will be for corn, versus how big the demand will be for corn,” particularly in the export markets.
For example, USDA reported export sales of U.S. corn that fell far below trade expectations for the week ended May 30. U.S. exporters sold 14,800 tonnes, including net cancellations of 8,700 tonnes of old-crop corn and net sales of 23,500 tonnes of new-crop corn.
The slide in corn futures was kept somewhat in check on Friday by news of productive U.S.-Mexico trade meetings, traders said.
Bilateral talks on migration resumed on Friday as Mexican officials continued their push for an agreement that would avert U.S. tariffs set to take effect next week.
The most-active wheat contract on the Chicago Board Of Trade settled Friday down 5-1/2 cents at $5.04-1/2 a bushel, down 1.27%. The contract closed the week up 0.29%.
Corn closed the day down 4-3/4 cents, or 1.13%, at $4.15-3/4 a bushel. Soybeans settled down 12-1/2 cents, or 1.53%, at $8.56-1/4 a bushel. Both posted their first weekly slide in a month. (Additional reporting by Naveen Thukral in Singapore and Sybille de La Hamaide in Paris; editing by Richard Chang and Susan Thomas)