Key Issues Perspective

Northern farmers have weed resistance, too

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

Even with all the attention directed toward weed resistance to various herbicides, and especially glyphosate, there are still too many farmers ignoring the messages or making only minor changes to their farming practices, especially in the northern Midwest.

Farmers need to plan for keeping resistant weeds at bay and not attempt to react to resistance when the first herbicide resistant weed is identified, explained Jeff Stachler, Ph.D., Extension agronomist for weed science and assistant professor at North Dakota State University and the University of Minnesota.

Stachler defines resistance more from a farmer angle. He said, “I now define resistance as the inactivity to respond to a changing weed population.”

Farmers cannot afford to ignore weeds that are showing resistance to any herbicide. He continued, “We don’t scout enough to know when the population is changing. We don’t understand the impact that one plant will have, and, therefore, we let it go because we’ll get it next time.”

Stachler explained his point of view on the current build up of weed resistance to herbicides, mainly glyphosate. He noted that if two weeds are resistant to nine-tenths of a full rate of herbicide and are only hit with nine-tenths of a full rate and survive, then the likelihood is that crossbreeding in the field of those two weeds will result in plants growing from the crossbred seed that are resistant to a full rate or higher rate of herbicide. Increased resistance will continue to balloon in each subsequent year’s batch of weeds.

“This is why I’ve come to the conclusion that zero tolerance is the only thing that you can accept. Can we get to zero tolerance all the time? No, but if we don’t try or talk about it, we can’t even get close to it,” Stachler said. His zero tolerance is zero weeds left in a field so that it is pristinely clean, as was the case when many farmers would hand hoe the last few weeds from their fields in the decades prior to the 1970s.

Weed resistance to herbicides in North Dakota and Minnesota where Stachler works is similar to reports across most of the upper Midwest. “It is very bad in some areas, and you can go to other areas and we have very little weed resistance to one or more herbicides. But it is pretty hard to not find a field in a county in all of Minnesota and at least the eastern two-thirds of North Dakota that doesn’t have glyphosate resistant weeds at this time,” he said.

Mike Jones, Bayer technical service representative in eastern Iowa, concurs with Stachler’s observations. “In the 20 counties in which I work, I’ve seen glyphosate resistance issues in each of them.”

Jones has watched as weed resistance has become obvious because of overuse of glyphosate. “Any herbicide that is overused will encourage weed resistance. You could say the weeds will adapt,” he said.

“Bayer is trying to point out the need for herbicide diversity as well as trait and crop diversity,” Jones said. “Respect the Rotation field days and materials are tools we have been using for the last three years to tell the message about weed resistance. We have also been working with universities—in my area it is Iowa State University—supporting their messages.”

Confirmation of weed resistance usually comes late in the cycle of resistance buildup in a field, noted Stachler. Although not officially confirmed in all cases, it appears there is probably glyphosate resistance to giant ragweed, common ragweed, waterhemp, marestail and kochia in his northern climate area. In other words, weed resistance isn’t being contained to the southern U.S. It has spread from border to border.

Prev 1 2 Next All

Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...

Comments (0) Leave a comment 

e-Mail (required)


characters left

Market Info






Demco 1400 Grain Cart

Demco offers a 1400 bushel grain cart to provide unmatched efficiency and operator convenience. In addition to the large 1400 ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form