Management Strategies for Difficult-to-Control Weeds (Driver Weeds)

There is a tremendous push in the agricultural industry to find solutions to problems such as herbicide-resistant weeds and other hard-to-control weeds — driver weeds — by utilizing a simple, one-pass system. However, if you listen to weed scientists from leading agricultural universities, you quickly learn that a simple, one-pass system is difficult, if not impossible, to achieve without further exacerbating the problem. 

So, what is a “driver weed”? A driver weed is a troublesome weed in your operation that you find difficult or impossible to control with traditional chemical means. Therefore, driver weeds drive your buying decisions as well as your willingness to try new practices to control them. In this new, biweekly blog series, we will discuss several driver weeds and consider options ranging from chemical control to management practices and trait systems to control them. Key driver weeds include Waterhemp, Palmer Amaranth, Marestail, Giant Ragweed and Kochia.

Background
The prevalence of herbicide-resistant weeds and the spread of these weeds steal headlines, but there are some weeds that are simply harder to control because of their biology and evolutionary resistance to certain control measures. Our pattern has been to find new chemical control measures that work and continue to use them year after year, season after season, and in all rotational crops. This strategy is a formula for disaster as it exponentially increases the rate at which selection for herbicide resistance can occur. For years, we have said “if” herbicide resistance occurs when we should say “when” herbicide resistance occurs because of our cultural and management practices. In this series, we will look at the biology, strengths and weaknesses of these driver weeds and examine alternative cultural and management practices that can be utilized in conjunction with trait systems to manage these weeds. We’ll discuss questions such as:

• What are the biology considerations of driver weeds?
  • When does it emerge?
  • What are its strengths?
  • What are its weaknesses?
  • What system type strategies can I use to eradicate this species from my farm?
• What herbicide technologies and trait systems will fit best for my strategy to control these driver weeds?

Stay tuned in the coming weeks for the next conversation in our series on driver weeds. And remember, if you have problems with hard-to-control weeds on your farm, you can always reach out to your local Stine agronomist for assistance.