Watch No-Till Weed Shifts

While weed shifts are certainly more prevalent than with other forms of tillage, following some common-sense strategies should help you successfully navigate through a changing weed spectrum.

The problem is your no-till weed control program dictates a shift to surviving weeds and not to those you effectively controlled.

“All weed control programs select or separate out weeds that are able to survive,” says Bob Hartzler, an Iowa State University weed scientist. “Weeds that survive a control tactic, such as a particular herbicide chemistry, produce seed and therefore increase populations. Weeds that are killed fail to produce seed, reducing their populations. So your weed spectrum shifts to the surviving weeds.”

When dealing with weed escapes, Dirk Drost, a technical brand lead for Zeneca Ag Products, suggests rotating herbicide chemistry and using tankmixes to keep weed gaps under control.

Waterhemp Concerns

One of the worst weed shifts Midwestern no-tillers witnessed in the ‘90s dealt with waterhemp. This obscure relative of pigweed quickly became a major weed problem.

When ALS-inhibitor herbicides came on the market in the late ‘80s, a number were very effective against waterhemp. But widespread use of ALS inhibitors caused a weed shift within a few years. Mike Owen, another Iowa State University weed scientist, says infestations of common waterhemp soon became a major weed problem throughout the Midwest.

While he says reduced tillage systems contributed somewhat to the weed shift, Owen believes selection pressure from the ALS inhibitors was the major factor. These herbicides demonstrated excellent activity on a…

To view the full article, please subscribe or login.
 Premium content is for our Digital-only and Premium subscribers. A Print-only subscription doesn't qualify. Please purchase/upgrade a subscription with the Digital product to get access to all No-Till Farmer content and archives online. Learn more about the different versions and what is included.
Lessiter_frank

Frank Lessiter

Frank Lessiter has served as editor of No-Till Farmer since the publication was launched in November of 1972. Raised on a six-generation Michigan Centennial Farm, he has spent his entire career in agricultural journalism. Lessiter is a dairy science graduate from Michigan State University.

Top Articles

Current Issue

NTF_December_1218

No-Till Farmer

Get full access NOW to the most comprehensive, powerful and easy-to-use online resource for no-tillage practices. Just one good idea will pay for your subscription hundreds of times over.

View More

Must Read Free Eguides

Download these helpful knowledge building tools

View More
Top Directory Listings