Glyphosate-resistant weeds have been on the rise over the past decade. Regardless of whether you’re experiencing weed resistance on your farm, it is important to remain vigilant in your weed management program. Take a proactive approach to managing weeds on your farm to prevent weed resistance.
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.
In Iowa, growers should watch for waterhemp and ragweed (giant and common). Reports of Palmer amaranth also are popping up around the state.
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.
“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 your 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 your fields. Consider the following scouting tips:
Be aware of weed types and common resistant species in your area.
Andy Asbury, Enlist field specialist, Dow AgroSciences
Prior to application, scout your field to identify the toughest-to-control weeds. Use full rates of the herbicides during applications.
Following each application, scout your 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 Enlist.com or talk with your Dow AgroSciences sales representative.
Trademarks of The Dow Chemical Company (“Dow”) or an affiliated company of Dow. Enlist Duo, Sonic and SureStart II are not registered for sale or use in all states. SureStart II is not available for sale, distribution or use in Nassau and Suffolk counties in the state of New York. Contact your state pesticide regulatory agency to determine if a product is for sale or use in your state. Always read and follow label directions. copyright 2015 Dow AgroSciences LLC