Don’t rely on a single tool for weed management

Andy Asbury
Enlist™ Field Specialist
Dow AgroSciences

Andy-AshburyGlyphosate-resistant weeds have been on the rise over the past decade. Regardless of whether growers are experiencing weed resistance on their farm, it is important to remain vigilant in their weed management program.

As the number of resistant weeds increases, controlling them becomes more complex. Start with clean fields and make timely herbicide applications. Apply when weeds are small and most easily controlled.

“On our farm, we’ve been seeing some glyphosate resistance with ragweed and waterhemp,” says Corey Strottmann, a grower from Story City, Iowa. “Glyphosate resistance is impacting our operation by costing us time and money.”

To control the tough weeds, Strottmann says his operation relies on a program approach and incorporates multiple modes of action.

Pay close attention to modes of action, especially when crops are not being rotated. Add a new mode of action to help prevent resistance issues.

Follow a program approach with multiple modes of action. Depending on tillage practices, you may apply a residual, such as Sonic® herbicide in soybeans or SureStart® II herbicide in corn, or a burndown and residual. Next, timely apply a postemergence herbicide, such as Enlist Duo herbicide for Enlist crops. In the fall, consider a fall burndown to help prepare for the next season.

And, don’t underestimate the power of scouting fields. Consider the following scouting tips:

  • Be aware of weed types and common resistant species in your area.
  • Prior to application, scout the field to identify the toughest-to-control weeds. Use full rates of the herbicides during applications.
  • Following each application, scout the fields to identify weed escapes.
  • Watch for noticeable patterns where weed escapes occur. Identifying potential resistance issues early will help prevent widespread distribution later.

New technology such as the Enlist system provides an additional mode of action to help control tough and resistant weeds. To make the most of new herbicides, it’s important to ensure the technology is used properly. Before you head into the field, calibrate your equipment, clean your screens and check your nozzles. This helps prevent potential breakdowns that could delay application.

Best management practices during application are key to ensuring the herbicide is able to do its job. Calibrate your sprayer for slower ground speeds and lower the boom height for better coverage. Be aware of surrounding fields and environmental conditions, such as wind speed and temperature inversions, when applying a herbicide.

For more information on the latest herbicide-tolerant trait technology available to help you manage hard-to-control and resistant weeds, visit or talk with your Dow AgroSciences sales representative.

Waterhemp is becoming harder to control on Corey Strottmann’s farm in Iowa. A few days after spraying Enlist Duo™ herbicide, waterhemp and other weeds were controlled.

Waterhemp is becoming harder to control on Corey Strottmann’s farm in Iowa. A few days after spraying Enlist Duo™ herbicide, waterhemp and other weeds were controlled.

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