A growing concern across the country is the development of herbicide resistance in weed species to glyphosate, or Roundup.
This herbicide has grown in popularity in crop production since it first came on the market years ago. With advanced technology we now have crops such as soybeans, corn, sugarbeets and alfalfa, which tolerate the herbicide.
But the widespread use of glyphosate has, in some instances, led to resistance development in some weed species. I listened to Neil Harker, a weed specialist from Canada who gave a presentation at the No Till On The Plains Winter Conference on this topic.
Pattern Is Clear
Harker showed the areas around the U.S. where resistance to glyphosate has developed in certain weed species and, as you would guess, the biggest concerns are in regions where growers are using Roundup Ready corn or soybeans in rotation on their farms.
In this region of the country there are now several weed species that are resistant to glyphosate herbicide.
Here in the Nebraska Panhandle, we’re at risk as well due to widespread use of Roundup Ready corn and sugarbeets. Many of us also use Roundup as a burndown prior to planting crops that aren’t Roundup resistant, such as edible beans, winter wheat, field peas, sunflower and millet.
There is also widespread use of Roundup with producers who are using chemical fallow in place of tillage fallow in winter wheat production.
Make a Plan
I think it’s in our best interest if we develop management strategies to combat the overuse of Roundup so it remains a viable herbicide in our crop-production practices. This includes proper crop rotations that allow growers to vary the herbicide, timing and mode of action with herbicides.
Proper crop rotations, with the use of pre-plant and post-emergence herbicides with residual activity, will allow growers to reduce the number of applications of Roundup or glyphosate.
On our farm we’re developing herbicide programs that will limit the use of glyphosate to no more than one per year on any field.
We plan to incorporate herbicides in our program that have enough residual to reduce the spraying of glyphosate and, in some cases, go even longer without using it. I think this strategy will greatly reduce the risk of developing weed resistance.
If you’re using Roundup Ready crops such as corn or sugarbeets, try to develop herbicide programs that also reduce the amount of times you apply the glyphosate herbicide.
For farmers using glyphosate herbicides rather than tillage in their wheat/fallow systems, I would encourage you to change your herbicide program or cropping system.
Possibly replace this long fallow period with a crop rotation or a cover crop, which might reduce the amount of glyphosate herbicide you’re applying on your fields.
We need to pay close attention to our herbicide programs that include the use of glyphosate herbicide and reduce the amount of times we apply this herbicide as much as possible.
Glyphosate herbicides have proven to be excellent herbicides for our crop production systems, but we need to use this herbicide in a prudent manner, which will insure its effectiveness in the future.