While driving along Interstate 39 from Bloomington to Rockford, Ill., last fall, John Pickle Jr. conducted a windshield survey based on looking at the four outside rows in corn fields that were running parallel to the highway. His quick and easy visual survey indicated that 60 percent of the corn fields had rodent damage.

Know The Cause. If you found small to large areas during last fall’s harvest where there were no plants and plenty of weeds, it will pay you to figure out what happened. Pickle says these spots could be caused by water, birds, insect or rodent damage. The spots often range in size from a few missing plants in a row to a bare area that covers as much as a quarter of an acre.

The crop consultant from Lodi, Wis., says there is a solution if the stand loss was caused by rodents. Compounding the problem is the fact that rodent damage is much more common in no-till fields.

“Rodent damage to the outside 4 to 12 rows of crop in a field is very easy to spot and correct,” he says. “You can also see rodent damage show up on combine yield monitors and visually as you run the combine. In most cases, the crop has been replaced by weeds, making harvest of the crop much more difficult.”

Three Critical Concerns. Pickle says the three main rodents that damage no-till corn are voles (meadow mice), 13-lined ground squirrels (striped gophers) and Ord’s kangaroos (sand rats). Each can cause significant damage in corn and soybean fields.

“If you think that you do not have rodent damage, just watch the outside 4 to 12 rows of corn that are located near grassy areas such as roadsides, grass waterways, wheat fields, alfalfa fields or fence rows,” says Pickle. “Many farmers and crop consultants do not recognize the damage as being caused by rodents and blame it on insects or equipment damage. As a result, they simply assume nothing can be done.”

Finding A Solution. While Pickle admits nothing can be done to correct areas already damaged by rodents, there is definitely something that can be done to eliminate the problem this year.

Having spent a number of years educating farmers on the importance of effective rodent control, Pickle says an application of Prozap Zinc Phosphide will eliminate the rodent problem in no-till corn fields. Now being marketed by the Neogen Corp. of Lexington, Ky., this restricted use pesticide is an effective and reasonably priced product for eliminating rodent damage in no-tilled corn. Unfortunately, there is not a registered product for rodent control in soybeans.

So take the time prior to spring planting to see if you can spot what caused those bare spots in your no-till corn and soybean fields last year. It may prove to be the most valuable crop scouting effort you make in 2005.