Slow crop development and the potential that USDA could lower its estimate of corn acreage cloud the outlook for U.S. corn and soybean production heading into Wednesday’s first USDA survey estimate of the 2009 crops.

The uncertainty has kept most trade estimates of the U.S. corn and soybean crops on the conservative side compared with the results forecast by crop weather models.

Analysts expect USDA to lower its estimate of this year’s soybean production moderately, largely due to the lateness of the crop.

Trade estimates of soybean production average 3.213 billion bushels in a range from 3 to 3.275 billion bushels, according to a survey taken by Dow Jones Newswires. That compares with USDA’s July crop projection of 3.260 billion bushels and last year’s actual crop of 2.959 billion bushels.

Prereport estimates of the national soybean yield average 42.1 bu. in a range from 40.9 to 43.5 bu./acre, compared with USDA’s previous trend-line yield estimate of 42.6 bu. and last year’s average yield of 39.6 bu.

Trade estimates of U.S. corn production average 12.472 billion bushels in a range from 11.792 to 12.814 billion bushels compared with USDA’s July projection of 12.290 billion bushels and last year’s crop of 12.101 billion bushels.

Estimates of the U.S. corn yield average 157.1 bu./acre in a range from153 to 160.3 bu./acre, compared with USDA’s July projection of 153.4 bu. and last year’s actual U.S. yield of 153.9 bu.

Editor’s note: Richard Brock, Corn & Soybean Digest's marketing editor, is president of Brock Associates, a farm market advisory firm, and publisher of The Brock Report.