Using Multiple Modes of Action to Manage Herbicide Resistance



Learn about the importance of using multiple modes of action to manage herbicide resistance on your farm.


There are many steps that every farmer can take to optimize weed control on farm and to help manage the potential for herbicide resistance and tough-to-control weeds. Using multiple modes of action is just one step when taking a ‘Start Clean & Stay Clean’ approach to weed management. Adding two or more herbicide groups to your spray tank where appropriate can help reduce the selection pressure caused by exclusive use of one herbicide group. Diversifying herbicides can reduce the risk of developing herbicide resistant weeds.

Tank mixing herbicides or using premixes with multiple modes of action in your herbicide application is one of the most effective ways to delay or prevent the development or spread of herbicide resistant weeds on-farm. The good news is that there are a wide variety of existing herbicides and labeled tank mixes that can be used as an effective solution to achieving sustainable weed control.

Applications & Products

The use of broad spectrum herbicides with varying modes of action, including those with soil active residuals, should be used as the foundation of weed control in canola, corn and soybean. Additionally, a diverse crop rotation will also help facilitate a comprehensive integration of different herbicide groups in a farmer’s weed control program.

Using Multiple Modes of Action Helps to:

  • Lower the risk of developing weed resistance.
  • Decrease shifts in weed populations on farm.
  • Increase yield potential by reducing weed pressure both pre-seed, and in-crop, as shown in canola, corn and soybean weed management systems.
  • Reduce the amount of weed seed return to the field.

 Weed Control Recommendations

  • Early season weed control is important to maximize yield potential of your crop.
  • Residual herbicides provide extended weed control, allowing for better post-emergent weed control and reduced overall weed pressure.
  • Weed staging can greatly affect herbicide efficacy. Using full labeled rates and applying herbicides when weeds are within the labeled stages are critical for optimal weed control.