“It’s been decades since farmers have had a truly new tool,” said Jody Gander, technical product manager with Bayer Crop Science. “These next-generation chemistries will help take back control over weeds that have adapted to everything we’ve had up to now.”
Bayer Brings Two New Active Ingredients
Bayer Crop Science has two new herbicide chemistries moving toward commercial launch. The first, Convintro, introduces diflufenican (Group 12), long used in Europe but new to U.S. corn and soybean systems. “That makes it a completely new active ingredient for American row crop farmers,” Gander said.
Bayer said it expects this chemistry to be available to U.S. farmers in 2026, pending regulatory approval. Convintro is to be labeled for preplant or preemergence use in corn and soybeans, and is expected to perform strongly on waterhemp and Palmer amaranth, Gander said. “Because it’s a single-active product, growers will be required to tank-mix it with another herbicide,” he said. “That not only broadens control but it also helps preserve the chemistry.”
Bayer is also developing icafolin, a new active ingredient for postemergence weed control, expected around the end of the decade. Icafolin-treated weeds become “frozen” in the field, meaning they stop growing and competing with crops, and eventually collapse into a surface residue layer — rather than the typical browning and wilting farmers expect, Gander explained. Bayer said the chemistry provides foliar and residual activity and has shown strong performance on resistant weeds such as Italian ryegrass in southern geographies. “Icafolin works differently from anything farmers have used before,” Gander said. “It changes the way we think about what weed control can look like.”
Bayer Announces Herbicide With New Site of Action for Soybean and Corn Market
Rice treated with Dodhylex active 37 days after treatment compared with weedy border. FMC
Keenali is a pre- to early-postemergence herbicide for rice, containing the Dodhylex active ingredient (tetflupyrolimet, Group 28), which introduces a brand-new site of action. It targets grass species and select broadleaf species.
“It’s the first new mode of action in my lifetime,” said Lawson Priess, an FMC technical service representative based in Arkansas. “Dodhylex active provides excellent residual control on barnyardgrass, sprangletop, and crabgrass.”
As of late November, the product was awaiting EPA registration, which FMC said it expects to receive in 2026, followed by a commercial launch in 2027. Keenali GR will serve as a stand-alone formulation for the California rice market, while Keenali Complete is targeted for Mid-South growers.
The Long Road to Discovery
Developing a new herbicide mode of action is a slow and complex process that can span more than a decade. The discovery pipeline today looks very different from decades past, said Nick Fassler, director of technical service for BASF.
“In the past, discovery meant testing large catalogues of chemicals through manual screening,” Fassler said. “Now, we’re focusing more on specific biological target sites within the pest, and the next frontier is figuring out how to leverage large datasets and artificial intelligence to make that discovery process more focused.”
Once a promising molecule is identified, Fassler explained, it must clear multiple rounds of testing — first for biological activity and crop selectivity, then for environmental and toxicological safety, and finally for formulation and field performance. Regulatory review and production scale-up add several more years to the timeline.
“From initial discovery to farmer use, you’re easily looking at 10–15 years,” Fassler said. “That’s why new modes of action are such a big deal when they finally make it to market.”
Fassler said BASF invests about $1 billion each year in agricultural research and development, with roughly $300 million and 12 years required to bring a single molecule from discovery to field. “The cost of failure is enormous,” he said, “but so is the cost of doing nothing.”
When Resistance Outruns the Toolbox
Waterhemp. Karla Gage, Southern Illinois University
The excitement surrounding new chemistry stems from a simple — and urgent — truth: Herbicide resistance has never been worse.
In Minnesota, the state’s most aggressive weed, waterhemp, has now developed resistance to six different sites of action, said Debalin Sarangi, Extension weed scientist at the University of Minnesota. “In some cases, glufosinate is the only postemergence option left — and we’re already seeing reduced sensitivity there,” Sarangi said.
One southwestern Minnesota population survived a full 32-ounce Liberty application, Sarangi said. “Liberty resistance is coming. It’s not widespread yet, but we’re putting a lot of selection pressure on it,” he said.
In Tennessee, in addition to problematic pigweed species such as Palmer amaranth and waterhemp, Larry Steckel, Extension weed science specialist at the University of Tennessee, has documented a rapid rise in herbicide-resistant grasses. “We’re running out of herbicides that do anything on pigweed,” he said. “And now, barnyardgrass, goosegrass, and Italian ryegrass are showing resistance to glyphosate and clethodim. We desperately need new options for grasses, maybe even more than for pigweed.”
Rye Randolph, who farms about 1,200 acres west of Peoria, Illinois, said staying clean has become labor intensive and expensive. “It used to be one postemergence pass,” he said. “Now it’s two or three, and my herbicide bill on soybeans is triple what it is on corn.”
Why Won’t Herbicides Alone Stop Waterhemp?
Beyond the Jug
Even as new chemistries enter the pipeline, researchers caution that no single product will solve resistance.
“The biggest mistake we see, year after year, is not doing enough up front,” Steckel said. “Residual herbicides are the backbone now — Dual; PPOs, like Valor; and other soil-applied products. You must keep weeds from ever emerging.”
Steckel and Sarangi stressed integrating cultural tactics. “You can’t manage resistance with herbicides alone,” Sarangi said. “You have to help your herbicide through crop rotation, cover crops, or mechanical control. And scout fields after spraying to pull escapes before they seed.”
The Future of Crop Protection: A Comprehensive Analysis of the Global Pesticides Market 2024-2033
Economic realities complicate that message. “Farmers agree with everything I tell them,” Sarangi said. “But every new practice costs money, and not everyone can take that risk.”
The Tillage Divide
While many researchers promote cover crops, some Midwestern farmers still rely on steel. Randolph is unapologetic about his approach. “Nothing’s resistant to cold, hard steel,” he said. “It costs less for me to run a field cultivator in spring than to spray a burndown. I start clean, and that’s worth a lot.”
Steckel doesn’t disagree. “There’s no resistance to tillage,” he said. “That’s one big reason resistance hasn’t spread as fast in the Midwest as it has here in the South. Unfortunately, our soils are too fragile to bring plows back.”
Protecting What’s Next
As exciting as products like Convintro, Keenali, icafolin, and other future next-generation actives may be, experts agree: Their longevity depends on stewardship.
“If we treat a new mode of action as a silver bullet, we’ll be right back where we started,” BASF’s Fassler said. “Mother Nature always finds a way around it.”
Fassler said BASF’s product labels emphasize tank-mix diversity and application limits. “The goal is to delay resistance, not chase it,” he said.
Bayer’s Gander echoed that sentiment. “History shows the quickest way to lose a product is to rely on it alone,” he said. “Convintro will launch with a required tank-mix partner.”
At FMC, stewardship is built into the product design. “From day one, Keenali Complete was intended to be used with another effective mode of action,” the company’s Priess said. “That’s how we keep Dodhylex effective for decades, not just a few seasons.”
Technology Tools
The John Deere See & Spray system uses an array of cameras on the boom arms to target weeds. Courtesy of manufacturer
Advances in precision application technology could help stretch the life of existing herbicides, but experts cautioned it’s not a cure-all. Steckel said optical and site-specific sprayers can reduce total herbicide use and slow resistance development but the industry still needs new chemistry. “You can’t spray your way out of this problem — even with better targeting,” he said.
In the Midwest, Sarangi noted that while camera-guided and sensor-based sprayers show potential, cost and calibration challenges limit their adoption. “We still need chemistries that perform well in small, targeted doses,” he said.
Fassler agreed that new herbicide formulations will likely be designed to work with precision systems. “There’s no single silver bullet,” he said. “It’s going to take the right mix of chemistry, application technology, and management to keep weeds under control.”
Looking Ahead
Despite daunting challenges, experts said they remain optimistic.
“I don’t think we’ll ever eliminate resistance,” Steckel said. “It’s biology and evolution — we’re just trying to live with it. But if we manage comprehensively, we can keep it from overwhelming us.”
Randolph, the Illinois farmer, said he hopes his son will inherit a future where solutions keep pace with problems. “Every time a new weed shows up, I hope we’ve got a new way to fight it,” he said.
Fassler said he shares that hope. “There’s as much investment in weed-control innovation now as ever,” he said. “When these new tools finally reach farmers, our job is to make sure they’re used right, so they last.”
