WEED MANAGEMENT IN 2022 WILL BE UNLIKE ANY OTHER SEASON.
Key postemergent herbicides are likely to be in short supply in spring 2022. But the weed management show must go on. Strategies will need to be tinkered with, and approaches will have to shift.
“There are products that are going to be tight. Early indications are that glyphosate, glufosinate, 2,4-D and dicamba burndown products could be in short supply. Growers have to think through how they can be proactive. This includes making products go further or simply limiting our reliance on these types of products,” says Matthew Wiggins, technical service manager for FMC.
“I start by thinking about how to make these solutions go further, and immediately my mind goes to focusing on residual chemistry both as part of our preemergent and postemergent programs. In 2022, we cannot, whatsoever, rely on cleaning up fields with a postemergent application.”
According to Wiggins, it all begins upfront with a strong, foundational residual preemergent herbicide that provides flexibility for growers’ postemergent application. Specific weed control options that fi t the bill include Authority® Supreme herbicide or Authority® Edge herbicide, which deliver an optimized ratio of the industry’s best Group 14 and Group 15 herbicides. These solutions are built for growers with wide-ranging soil and field conditions from light soils to heavy soils with high organic matter, all while delivering long-lasting residual weed control. In particular, they target weed species like waterhemp and Palmer amaranth that other chemistries might struggle to manage.
Bill Johnson, professor of weed science at Purdue University, echoes a similar recommendation as Wiggins, particularly for those growers who plant Enlist® or Roundup Ready 2 Xtend® soybeans.
“I want to see us go out earlier in the spring and layer in a residual herbicide to give growers depth protection. For those Enlist and Xtend soybean users, we need to build a weed management program that puts out one postemergent pass. Our quantities will allow only one pass,” Johnson says. “We need to load up on the residual in the preemergent and spray our Enlist® or XtendiMax® herbicide early postemergence and layer another residual alongside that. Most common are the Group 15 herbicides to pair with an Enlist or XtendiMax herbicide application.”
To bolster the residual weed control of these preemergent herbicide applications, focus on utilizing multiple effective modes of action. This will help provide flexibility in the postemergence stage.
CUTTING APPLICATION RATES IN 2022 SPELLS DOWNSTREAM ISSUES
Even with the supply constraints, weed management best practices need to be upheld. One in particular rises above the rest: application rate integrity. For those growers who can get their hands on glyphosate, glufosinate, 2,4-D and other postemergent products, it will be tempting to dial back the label’s recommended use rate in order to spread their product stock out across as many acres as possible. 2022 is not the year to start cutting effective rates, especially when it comes to residual herbicides.
Wiggins points out that rate cuts in the past have been a red flag for herbicide resistance development.
“When supply gets tight or prices increase, some growers will cut their application rates. Historically, this isn’t a viable option. We have to continue to use full label use rates, or we will create a headache for ourselves down the road,”
Wiggins says. “2022 could be a tipping point. We could look back five or six years from now and identify areas of escapes or increased herbicide resistance in places where herbicide applications were made below recommended rates. Growers have done a good job of managing weed species, so let’s not let that diligent work go to waste.”
To mitigate the effect of weeds on yield potential and their contribution to the weed seedbank, Wiggins implores growers to carefully craft a weed management plan and stick to it.
“If we make a decision on our plan, let’s do our best to implement it in it’s entirety. This includes not cutting corners on rates or applying herbicides that do not have a good residual. Don’t let it fall apart at the last minute because of one hiccup.”
XtendiMax herbicide is a Restricted Use Pesticide. Always read and follow all label directions, precautions and restrictions for use. Some products may not be registered for sale or use in all states. FMC, the FMC logo and Authority are trademarks of FMC Corporation or an affiliate. Enlist is a trademark of a trademark of Dow AgroSciences, DuPont or Pioneer and their affiliated companies or respective owners. Roundup Ready 2 Xtend and XtendiMax are trademarks of Bayer or an affiliate. ©2022 FMC Corporation. All rights reserved. 22-FMC-3223 02/22
