U.S. crop conditions ratings held steady last week, but crop maturation remained well behind normal as wetter weather hit the main Midwest production belt.

Improved conditions in parts of the western Corn Belt offset a drop in Illinois crop conditions and the U.S. corn crop rating held at 61% good/excellent, while the soybean crop rating held at 57% good/excellent in Monday afternoon’s weekly crop update from USDA.

USDA reported that only 19% of the U.S. corn crop was mature as of Sunday, compared with a five-year average of 44% for the date. Only 21% of the U.S. soybean crop was said to be dropping leaves against an average of 41%.

Crop maturation is running as much as three weeks behind in key growing areas of the Midwest. In the No. 2 corn- and soybean-growing state of Illinois, only 16% of the corn crop was said to be mature against a five-year average of 58%, and just 7% of the soybean crop was dropping leaves against an average of 39%.

In the top-producing state of Iowa, only 11% of corn was mature against an average of 45%, while 16% of the soybean crop was dropping leaves against an average of 44%.

The maturation process is expected to be further slowed by the heavy rains that hit the upper Midwest last weekend as remnants of Hurricane Ike blew through. Illinois felt the hardest impact from Ike, with northern parts of the state receiving 7-10 in. of rain.

Largely as a result of the soaking, the good/excellent rating for Illinois’ corn crop dropped by 6 percentage points to 66% and the good/excellent rating for Illinois soybeans fell by 4 percentage points to 63%.

University of Illinois Agricultural Economist Stu Ellis told the Associated Press on Monday that the heavy rains could provide the right environment for fungus to sprout and spread in soybean fields.

"What this rain is going to do is create a lot of ponding in the fields," says Ellis, who is also the editor of the U of I's farmgate Web site.

"The wet feet for beans could spell fungus. I guess if there's good news, it's that we've seen no forecast for frost. The bad news is that I don't think it's going to get hot enough in the short-term to dry the fields as quickly as farmers need to get in."

Ellis says the rains will especially be problematic for what he called "droughty" corn, which could also be susceptible to fungus.

"I think corn, especially corn with weaker stalks, could see some lower yields," Ellis says.

Any further delays to crop maturation will boost the risk of crop production being trimmed by frost, however, forecasters say the risk of an early Midwest frost has diminished and the Midwest will see much improved weather over the next week.

The area is expected to see clear skies and warm temperatures for the next seven days, forecaster Mike Palmerino of DTN Meteorlogix told Reuters News Service on Tuesday.

"A stretch of warm, dry weather will help the Midwest dry out from the heavy rains and no damaging cold weather is in sight," says Palmerino.

"Considering what happened with heavy rains over the weekend, this is the best you could hope for," he says.

Worries about an early frost have dissipated partly because the Southern Oscillation Index has taken a sharp turn into positive territory in the past month, indicating La Nina-like conditions may be reforming in the southern Pacific Ocean.

The presence of La Nina conditions normally means a warmer-than-normal fall in the Midwest and an active tropical storm season.

The most-likely scenario now is for freezing conditions to arrive across the Midwest at no earlier than normal dates. However, later-planted crops are maturing very slowly and some fields will be vulnerable to even a normal first frost.

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.