Tuesday morning’s Annual Crop Report is expected to show a modest reduction in the size of the U.S. corn crop due to low test weights and harvest problems, while the size of the soybean crop is expected to grow slightly due to strong yields.

Trade estimates of U.S. corn production average 12.819 billion bushels in a range from 12.5 to 12.996 billion bushels compared with USDA’s November estimate of 12.921 billion bushels and last year’s 12.101-billion-bushel crop, according to a survey conducted by Dow Jones Newswires.

The consensus for a smaller corn crop is strong. Nineteen of 22 analysts surveyed by Dow Jones forecast that the size of the corn crop would shrink.

Estimates of soybean production average 3.337 billion bushels in a range from 3.219 to 3.42 billion bushels compared with USDA’s November survey estimate of 3.319 billion bushels and last year’s 2.967-billion-bushel crop. Sixteen of 22 analysts surveyed expected an increase in soybean production.

Pre-report expectations of the U.S. soybean yield average 43.4 bu./acre in a range from 40 to 44.7 bu., up slightly from USDA’s current estimate of 43.3 bu.

Trade estimates of the national corn yield average 162.5 bu./acre in a range from 160 to 164.5 bu., down from USDA’s November estimate of 162.9 bu.

Widespread reports of lower-than-normal test weights for corn combined with the lateness of the harvest are the main reasons the corn crop size is expected to shrink.

Whatever Tuesday’s crop report shows, corn market will remain uncertain about the final crop size with 4-5% of the crop still unharvested and trapped in the field by winter weather.

Estimates of field losses on that unharvested portion of the crop run 50-100 million bushels, but the extent of the losses won’t be clear before spring.

Strong soybean yields across the Midwest are expected to offset the negative impact of field losses in Delta growing states due to heavy fall rains that caused flooding in fields there. Field losses appear to have been limited in top soybean-producing states.

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.