U.S. corn and soybean conditions slipped last week as a lack of significant rainfall and high weekend temperatures stressed crops in some areas of the Midwest.

Monday afternoon’s weekly USDA crop update pegged U.S. corn conditions at 70% good/excellent as of Sunday, down from 73% a week earlier, but above the year-earlier rating of 63%.

U.S. soybean conditions were rated 65% good/excellent, versus 68% a week earlier and 58% a year earlier.

Crops continued to develop ahead of schedule under warm conditions. USDA reported 32% of the U.S. corn crop was already silking as of Sunday, compared with a five-year average of 18%.

Some 40% of the U.S. soybean crop was said to be blooming, up from a five-year average of 28%.

Among the top producing states, the strongest evidence of crop stress came in Minnesota, where the good/excellent rating for corn fell 7 percentage points and the soybean rating fell 8 points.

However, 67% of Minnesota corn is still rated good/excellent as is 65% of the state’s soybean crop.

In the top U.S. corn and soybean growing state of Iowa, the good/excellent ratings for both crops were down by 4 percentage points to 72% good/excellent.

In its weekly report, the Iowa office of the National Agricultural Statistics Service said crops are showing signs of stress from high temperatures and low moisture. “Leaves are curling from lack of moisture as few areas of the state have received significant rainfall recently,” the report said.

Iowa topsoil moisture was still rated 66% adequate/surplus, down from 71% a week earlier, with subsoil moisture rated 71% adequate/surplus, down from 84%.

Iowa crops are advancing rapidly. Some 37% of the corn crop was reported tasseled, 3 days ahead of last year and six days ahead of the five-year average of 13%. Some 18% of the Iowa crop has already silked, which is five days ahead of normal.

In No. 2 corn and soybean producer Illinois, both corn and soybean conditions improved last week as crops continued to benefit from good late June rains.

The Illinois corn crop was rated 81% good/excellent, up 2 percentage points from a week earlier, while the soybean crop was rated 76% good/excellent, up from 73% last week.

Illinois crop development is well ahead of normal with 68% of the crop already silking, double the five-year average. Some 51% of Illinois soybeans are already blooming compared to 33% last year and the five-year average of 31%.

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

To see more market perspectives, visit Brock's Web site at www.brockreport.com.