Mix Up Your Sites of Action

Mix Up Your Sites of Action

Mix up your sites of action this growing season to manage and control tough weeds.

Change can be scary. Especially when what you have done in the past has worked well. However, sometimes it’s necessary to mix things up for the greater good of your yields and stewardship of the land. This couldn’t be truer when it comes to sites of action for weed control.

A site of action is the location in a plant where an active ingredient of a herbicide disrupts the development process. Using the same sites of action targets the same locations within a weed. And using a single site of action only attacks a weed in one location, thus in one way. Doing this year after year will not do you any favors in the long run. In fact, repeating herbicide sites of action can contribute to the development of herbicide-resistant weeds, which threaten the stewardship of your land and the legacy you hope to pass on. Now is the time to embrace change and protect your farm for future generations. Mixing up your sites of action is an important part of an integrated weed management program, which will help protect your yields this year and for years to come.

Tankmixing enhances rotation

While rotation is an important practice, it is even more important to combine multiple effective sites of action.

In any population of weeds, some will be naturally resistant to a single site of action. Combining multiple sites of action is an essential practice for controlling these naturally resistant weeds. In fact, recent research by the University of Illinois suggests that growers who use an average of 2.5 effective sites of action per application are 83 times less likely to have herbicide resistant weeds than those who use 1.5 effective sites of action per application.i Tankmixing multiple sites of action can enhance your herbicide program to ensure fields stay weed-free.  

Plan on using multiple, effective sites of action every time you spray, whether it be within the same growing season or from year to year.

Developing your herbicide program

A zero tolerance approach is one that focuses on eliminating weeds before they set seed and multiply. Herbicides are just one part of an effective zero tolerance strategy. To maximize efficiency of your herbicide application, mix up your sites of action by following these three steps.

  1. Identify problem weeds
    Knowing the resistance profile of problem weeds you plan to tackle is an important first step for weed control. When developing your herbicide program, plan on incorporating sites of action that target problem weeds specifically.
  2. Reference product labels
    The Weed Science Society of America assigns numbers to different sites of actions, which are easily found on the product label. Intentionally select multiple and different sites of action that are effective against the weeds you plan to fight. This knowledge is essential for planning different mixtures and rotations.
  3. Customize your tankmix
    Look for herbicide programs that allow for tankmix flexibility to achieve multiple sites of action. Being able to customize your herbicide program allows you to target problem weeds without repeating the same combinations of sites of action from previous years or applications.

Bayer herbicide solutions

Mark Waddington, selective corn herbicides product development manager at Bayer, recommends the two-pass program of Corvus® Herbicide followed by DiFlexx® DUO Herbicide.

Corvus (Groups 2 and 27) is a pre-emergence herbicide that provides superior control of emerged weeds due to its long-lasting residual and unique feature of reactivation. With as little as a half inch of rain, Corvus reactivates to wipe out weeds that may have emerged later in the season, even after extended dry periods. DiFlexx DUO (Groups 4 and 27) is a postemergence herbicide that takes down tough-to-control weeds, including driver weeds.

“When combined, Corvus and DiFlexx DUO give growers the ability to develop strong weed management programs around three effective sites of action,” said Waddington. “To further mix up your sites of action with this herbicide program, add different tankmix partners both pre- and post-emergence.” 

Bayer offers a full spectrum of options that can be tankmixed with Corvus or DiFlexx DUO, such as Harness® Brand Agricultural Herbicides and Roundup® Brand Agricultural Herbicides.

Corvus (2, 27) is easily tankmixed with atrazine (Group 5), Roundup Brand Agricultural Herbicides (Group 9), DiFlexx (Group 4) and Harness Brand Agricultural Herbicides (Group 15).  

Recommended tankmix options for DiFlexx DUO (4, 27) include Roundup Brand Agricultural Herbicides (Group 9) and atrazine (Group 5).

Talk to your local Bayer representative or retailer about the weeds you are fighting in your fields to develop an integrated weed management program that will help you mix up your sites of action.



©2019 Bayer Group. Always read and follow label instructions. Bayer, the Bayer Cross, Corvus, DiFlexx, Harness and Roundup are registered trademarks of Bayer Group. Corvus is a Restricted Use Pesticide. Not all products are registered in all states. For additional product information please call toll-free 1-866-99-BAYER (1-866-992-2937) or visit our website at www.CropScience.Bayer.us. Bayer CropScience LP, 800 North Lindbergh Blvd, St. Louis, MO 63167.

Works Cited

i Henry, S. “Illinois: Tank Mixing Vs Herbicide Rotation To Stop Resistance?” Agfax, 2015. https://agfax.com/2015/05/20/herbicide-resistance-tank-mixing-more-effective-than-rotation/

Copyright © Bayer CropScience