Don’t Let Resistance Take Root: 4 Simple Tips for Smarter Weed Control

If managing herbicide resistance were easy, it wouldn’t still be a topic of concern and conversation.

“Weed resistance management is a heavy lift,” says Mark Heineman, HELM Crop Solutions technical agronomist. “We’ve become less engaged in our knowledge around herbicides, which fuels the challenge. Pricing pressures also play a role, especially in current market conditions.”

Weeds don’t care about these factors. Herbicide resistance continues to trend upward, driven by the complex challenges facing growers and retailers as they work to overcome the issue.

It’s time to strengthen your knowledge and direct fresh attention to burndown applications, because weeds are taking full advantage of resistance management missteps.

Research shows:

• Globally, there are 534 unique cases of herbicide resistance spanning 273 weedy species and 168 different herbicides across 21 of the 31 herbicide modes of action (MOA)
• Herbicide-resistant weeds have been found in 98 crops across 72 countries
• More than 130 unique cases have been documented in the United States

So, how do growers and crop advisors break this cycle? Here are four things to consider as you view herbicide resistance as a holistic weed management program strategy during the burndown period and beyond.

1. Trace herbicide history and MOA before applying.

Resistance management advice hinges on changing up MOAs, like incorporating Reviton herbicide into your program and using multiple MOAs.

But the marketplace is also filled with herbicides either coming off-patent or already off-patent. The result is many different product names may feature the same MOA.

“Growers trying to do due diligence in managing resistance tend to rotate or switch products every so often, but sometimes the product name changes, not the actual chemistry,” cautions Heineman. “This adds confusion and frustration.”

Take the time to research product labels before purchase and application. Doing so helps develop a clearer understanding of each MOA and how it fits into your overall program.

2. Rates and active ingredient (AI) percentages matter.

Adding to the complexity, different products may contain varying percentages of AI. Always consider application rates for all products used.

“We have different products that are the same chemistry,” says Heineman. “But then we have the same products with different percentages, as well.”

That’s why rates become extremely important.

“Chemical products usually have rate ranges for proper performance. Keep in mind, a product you bought two years ago may have had a higher concentration, which changes how effective today’s application with a different product will be,” says Heineman.

3. Do the little things right.

The basics of weed management matter more than ever. Actively walking fields throughout the season helps identify which species a program is missing and when escapes occur.

“These foundational things are all about evaluating application methods and attention to detail,” says Heineman. “Whether that’s improper application methods, not a high enough rate of AI, poor coverage with the wrong rate, nozzle choice, application speed or weed size at application.”

These details make the difference between success and resistance pressure.

4. Re-engage and focus on intentional actions.

It takes commitment across the value chain to build effective weed management strategies and keep resistance in check.

“Good retailers and crop advisors are involved at the farm gate, not just with field trials,” says Heineman. “They’re engaged in what their growers see in fields and help sort through marketplace complexity.”

Ultimately, managing resistance means investing in the right program upfront.

“Remember, the cheapest herbicide programs are not necessarily the most effective,” says Heineman. “Rescue programs are usually twice as expensive as doing it right the first time.”

By taking a proactive, knowledge-driven approach, you can strengthen your weed control strategies and gain the upper hand in the fight against resistance. Together, these steps keep you in control – not the weeds.