Why Fall Burndown Beats Spring Weed Control
That’s why I always encourage making a burndown application in the fall when weeds are easiest to control. This is incredibly important for those who practice minimum/no-till and have a history of winter annuals.
So, why do some farmers shy away from making a fall burndown application? If I had to guess, I’d say most don’t want the added cost. This application comes when you have finally recouped input costs from the spring crop and are looking to purchase seed for next year. I understand this hesitation, but the weeds don’t care.
Fall Burndown Provides Efficacy at a Low CostThe good news is that a fall burndown application doesn’t need to be complicated or expensive to be effective. In fact, even a late fall burndown made shortly before freezing is likely to provide far better results than a spring herbicide tank mix at a fraction of the cost.
Provided you’re planting a herbicide-resistant crop next spring, all you need to include in your burndown application this fall is glyphosate, a growth regulator like 2,4-D or dicamba to target glyphosate-resistant weeds and the appropriate adjuvant package. I usually recommend a tank mix containing the following products:
- WinField United Cornerstone® 5 Plus herbicide (glyphosate).
- WinField United Shredder® E-99 herbicide (2,4-D).
- WinField United Class Act® NG® adjuvant, which contains a quality nonionic surfactant.
- WinField United InterLock® adjuvant to lock in spray coverage and lock out drift.
Is Residual Chemistry Needed?If you’re planting a herbicide-tolerant crop next season, it isn’t necessary to include a residual herbicide in your fall burndown application unless you’re dealing with a complex weed issue. In most cases, you can just come back next spring and clean up newly sprouted weeds with the appropriate postemergent herbicide application.
But if you’re planting a conventional crop, wheat on no-till or minimum-till acres, or pulse crops like peas, lentils, chickpeas or dry edible beans, it’s best to include a fall residual product in your burndown tank mix. An effective flumioxazin option like Valor® herbicide applied in the fall will continue to suppress marestail, narrowleaf hawksbeard and downy brome in the spring.
The Downsides of Relying on a Spring ApplicationWheat producers who practice minimum/no-till and skip a burndown application this fall will be forced to deal with broadleaf weeds and downy brome next spring. Pyroxsulam products like OpenSky® and GoldSky® herbicides are the best options for controlling downy brome on wheat and other cereal crops. Everest® 3.0 herbicide also offers residual control, but it isn’t used as often as the others due to its longer rotational restrictions.
Whichever of these products you choose, relying on it for your spring herbicide application will cost about $30 per acre1. You’d hope to get excellent control for that investment, but these tank mixes are not a silver bullet. Since weeds that started growing in fall are larger and harder to manage come spring, farmers are often disappointed by the modest results they attain.
Choosing between spending $10-20 per acre this fall to achieve effective control or $30 per acre next spring to get mediocre results is a no-brainer. Depending on the size of your operation, you can save thousands of dollars with a fall burndown application, all while receiving better results.
Timing is Important, But Not an End AllThe best time to make your fall burndown application is when weeds germinate after harvest, generally mid-September in the Northern Plains. But, as I implied earlier, you can still achieve adequate control if you apply a fall burndown before the first heavy freeze or even post freeze if warmer temperatures return for an extended amount of time before winter ultimately arrives.
I saw firsthand what a late application can do last fall when I made a burndown application on some volunteer wheat in a local grower’s field. As it turned out, it snowed the next day and didn’t end up melting off until spring. I thought that application would be a lost cause, so imagine my surprise when I saw excellent results in the spring. In addition to eliminating the volunteer wheat, there were perfect strips of black soil where we sprayed, but carpets of cheatgrass had started growing in the unsprayed border areas.
If you’re tired of large weeds and winter grasses outlasting your spring herbicide treatment and reducing your yield potential, consider making a burndown application this fall. Your local WinField United retailer will help custom tailor the right tank mix for your operation.
1Per acre herbicide application costs are supplied only as an estimate and will vary depending on current pricing and rates.
All photos are either the property of WinField United or used with permission.
© 2022 WinField United. Important: Before use always read and follow label instructions. Crop performance is dependent on several factors many of which are beyond the control of WinField United, including without limitation, soil type, pest pressures, agronomic practices and weather conditions. Growers are encouraged to consider data from multiple locations, over multiple years and to be mindful of how such agronomic conditions could impact results. Class Act, Cornerstone, InterLock, Shredder and WinField are trademarks of WinField United. All other trademarks are the property of their respective owners.
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