U.S. corn conditions deteriorated slightly last week as hot weather took a toll on fields stressed earlier by excessive rains, but soybean conditions improved as the northern part of the Delta region saw needed moisture and wet fields in Illinois dried out.

USDA rated U.S. corn conditions 72% good/excellent, down 1 percentage point from a week earlier, but up 1 point from a year earlier.

Soybean conditions were rated 67% good/excellent, up 2 percentage points from a week earlier and on par with a year earlier.

The U.S. corn crop continued to develop at near-record speed in hot, humid conditions, with USDA reporting that 65% of U.S. corn was silking as of Sunday, nearly double the year-earlier pace of 35% and 18 points above the five-year average.

Soybean development also remained slightly ahead of the normal pace with USDA reporting that 60% of the crop was blooming vs. a five-year average of 56%, while 18% of U.S. soybeans were setting pods against an average of 15%.

Corn conditions declined slightly in the top producing state of Iowa, where the crop was rated 69% good/excellent as of Sunday, down from 71% a week earlier. The Iowa soybean crop was also rated 69% good/excellent, unchanged from a week earlier.

The deterioration of the Iowa crop was offset by improvement in the No. 2 producing state of Illinois, where the crop was rated 67% good/excellent up from 65% a week earlier.

Illinois soybean conditions, meanwhile, improved to 64% good/excellent from 62% a week earlier.

Illinois corn development is well ahead of schedule with an estimated 89% of the state’s crop silking as of Sunday compared with only 24% of last year’s late crop and a five-year average of 65%.

Some 18% of Illinois corn has already reached the dough stage of development compared with the average pace of 10%.

With corn development well ahead of normal and weather forecasts calling for good rains across the heart of the Corn Belt this week, the U.S. crop should make it through the key pollination period without widespread stress.

Meanwhile, most of the soybean crop appears likely to go into its key growing stage having good soil moisture to work with.

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.