March 28, 2024

The three R’s of good weed management

MARKLE, Ind. — The three R’s traditionally represent reading, writing and arithmetic. When he’s talking about Acuron corn herbicide, Chad Threewits, Syngenta agronomy service representative for Indiana, wants farmers to think about resistance, rates and revenue potential.

Using the full labeled rate of Acuron can help delay or prevent herbicide resistance and can contribute to increased revenue potential.

“I would say, starting off, that resistance continues to be a big driver of what we do with herbicide programs, across not only Indiana, but the Midwest and the whole United States. It’s not just a local problem,” said Threewits.

Threewits knows herbicide resistance can be a difficult topic to discuss with farmers. Applying the correct rates of herbicide and timing of application are priorities, but many times circumstances beyond farmers’ control can disrupt even the most meticulous herbicide program.

“It’s a very broad, complex issue when you look at herbicide resistance. One way it develops is by reducing rates. That may be intentional or unintentional,” Threewits said.

The list of weed resistance causes is long and includes items that are within the farmer’s power to control — and outside a farmer’s power to control. But intentionally applying reduced rates is a big factor.

“Without full rates, those plants can then withstand the herbicide application and survive. If a weed withstands an application, it can now start that process of having tolerance to the herbicide, and that eventually turns into resistance where it will not be able to be killed by that active ingredient,” Threewits said.

More Than Meets The Eye

Using Acuron and using the right rate at the right time can be the key to preserving herbicide efficacy.

“Having a focused and planned approach, in this case by using full rates applied at the right time, is going to be a very strong tactic,” Threewits said.

A herbicide program is judged to be successful when a field is clean at harvest. But a clean field may not tell the whole story — and it may not guarantee that herbicide resistance is not occurring.

“We may have made an application earlier in the season that didn’t work and then had to come back again with a different herbicide to try to treat those weeds that were resistant to the first application. A lot of times, resistance goes unnoticed until we see maybe 30% of the weeds in the field that are truly resistant. Once you get to that point, it can spread really fast,” Threewits said.

Unmanaged weeds can impact crop growth through the competition for nutrients, sunlight and water, which can ultimately reduce yields. Studies by Syngenta found that 1-inch to 2-inch weeds consumed over 9 pounds of nitrogen per acre. Those studies also showed that in three days, 3-inch weeds can take up an inch of water.*

“All of those things can work together and put stress on the crop and result in decreased yield,” Threewits said.

Today Changes Tomorrow

Threewits emphasizes the importance and necessity of preventing and delaying herbicide resistance simply to preserve the efficacy of current herbicides.

“In the foreseeable future, there really are no new herbicide sites of action that are coming. This is why we do a lot of research every year and try to improve the products,” he said.

In that arena, of preemergence herbicide products that have been developed to address resistance issues while providing full-spectrum weed management, Acuron is a product that stands out.

“The unique active ingredient in Acuron is bicyclopyrone. Bicyclopyrone was developed to help manage the weeds that are now becoming more of an issue,” Threewits said. “In combination with the other active ingredients in Acuron, it delivers powerful weed control, longest-lasting residual and proven crop safety.”

This unique combination enables Acuron to provide increased revenue potential, and help delay or prevent herbicide resistance, Threewits said. When used preemergence at the full labeled rate, Acuron outyields competitive corn herbicides by 5-15 bushels an acre.**

“When we think about using full rates, Acuron corn herbicide really has unmatched weed management, whether we are looking at the preemerge or post-emergence market. Having four active ingredients and three effective sites of action really allows us to maximize the weed management and also delivers that higher yield potential,” he said.

This column was contributed by Indiana AgriNews for Syngenta.

*2006 Syngenta trial: York, NE.

**Acuron yield advantage range based on 2016 Syngenta and University trials comparing Acuron to Corvus®, Resicore®, SureStart® II and Verdict® applied preemergence at full label rates. For more information on Acuron versus an individual product, ask your Syngenta representative.

Acuron is a Restricted Use Pesticide. Acuron® is a registered trademark of a Syngenta Group Company. All other trademarks are the property of their respective owners.

Jeannine Otto

Jeannine Otto

Field Editor