MILWAUKEE -

Some of Wisconsin's largest farm groups are worried federal regulators will expand restrictions on atrazine, a weed killer sprayed on corn fields and other crops.

The Milwaukee Journal Sentinel reported that the U.S. Environmental Protection Agency issued a draft ecological risk assessment of atrazine this summer and recommended reducing the allowable levels.

Farm groups have asked farmers to contact the EPA and urge the agency to reconsider its stance.

Wisconsin Corn Growers Association officials say the reduced allowable levels would effectively ban the use of the weed killer in nearly 100 herbicide mixes.

Other groups urging the agency to rethink the restrictions include the Cooperative Network, Wisconsin Pork Association, Midwest Food Processors, the Dairy Business Association, Wisconsin Farm Bureau Federation and the Wisconsin Soybean Association.