Farm and Field

Cooperative weed management could curb herbicide resistance

Posted: Jul. 1, 2018 12:01 am

In the fight against herbicide resistance in waterhemp, farmers are working with a shrinking toolkit.

But scientists at the University of Illinois and U.S. Department of Agriculture's Agricultural Research Service offer a new tool that is not only highly effective but free. All it costs is a conversation.

The tool is cooperative weed management -- making decisions about how to manage herbicide-resistant weeds in cooperation with neighboring farms. The more farms working together, and the larger area covered, the better.

"If you take the cheap route, you'll save some money in the short term on your herbicide costs, but in the long term, you'll have a much greater likelihood of developing resistance," said Adam Davis, research ecologist with USDA-ARS and adjunct U of I professor.

But if farmers invested in tank mixtures of herbicides representing three or four modes of action, the evolution and spread of resistance was delayed, and the delay got longer with increasing levels of cooperation.

"The message is not to use the most expensive herbicide program possible; the message is to use the available tools to manage your weeds better," Davis said. ‘If you do that on your own farm, certainly it's going to help. If you do it on a bunch of adjoining farms, it's going to help even more. You can buy a couple of decades of time, in terms of delaying herbicide resistance evolution, by aggregating the best practices at large spatial scales."

A research simulation looked at management on individual farms, cooperatives of 10 neighboring farms and cooperative weed management areas of 10 neighboring farmer cooperatives.

Davis said the specific number of farms making collective weed management decisions isn't as important as the spatial scale they cover. He suggests forming weed management areas at the township scale and above, pointing to existing drainage districts or commodity groups as possible models for how weed management cooperatives might operate.

Cover crop app

The Midwest Cover Crops Council has reformatted its popular field guide as an app for smartphones and tablets.

The Midwest Cover Crop Field Scout app lets farmers, crop advisers and conservation professionals access vital cover crop information from mobile devices.

The app improves on the printed guide by providing additional photos and links to more in-depth articles. Once downloaded, app content will be available anytime on a mobile device. An internet connection is not required to view cover crop information in the field, MCCC program manager Anna Morrow said.

The app is available for both iOS and Android devices with a $2.99 annual subscription. The fee allows MCCC to update the app throughout the year.

Users will get a renewal reminder when their subscription is nearing its end. Bulk purchase will be available for companies and field day organizers, allowing groups to offer free downloads at special events.

Find the app by searching "cover crop" in either the App Store or Google Play. More information and links are at