Wet weather and cool temperatures are causing headaches for northern Minnesota corn farmers, and U.S. Rep. Collin Peterson has asked federal officials to cut them some slack.

Federal crop insurance won't fully cover corn that's planted after May 25 or grain and silage after May 31, but Peterson has asked the U.S. Department of Agriculture to delay those dates.

"In many parts of my district, wet weather has prevented farmers from even getting fields ready for planting, much less actual planting," Peterson wrote. "My growers would rather produce a corn crop than collect a prevented planting [insurance] claim."

Peterson is the ranking Democrat on the House Agriculture Committee. A committee spokeswoman said Thursday that Peterson has not received a response yet, and his request is being reviewed.

Crop insurance reduces risks for growers who may experience poor or ruined crops due to weather or other problems. Policies may be based on expected yield or price, and their terms vary widely depending on the type of crop and the location and crop history of the farm.

However, most policies require that producers have crops planted by certain deadlines, or they enter into what's called a "late planting period." For every day that farmers have not planted in the late planting period, their guarantees of recovery are reduced by 1 percent.

So farmers face a choice of planting late and having their risk coverage reduced, or not planting at all and making a "preventive planting" claim.

USDA reported that as of Sunday, growers had planted 53 percent of the corn crop in Minnesota, but Peterson noted that much of that work has been done in the southern half of the state, not in the northwest part that he represents.

Other crops also are getting a late start this season. Only 16 percent of soybeans have been planted statewide, according to USDA, compared with a five-year average of 45 percent at this time. And 40 percent of sugar beets have been planted, compared with the five-year average of 79 percent.