Just ahead of the Fourth of July holiday, EPA took a major step toward bringing several new herbicide technologies to market, advancing six herbicide registrations that could eventually give farmers more tools to fight herbicide-resistant weeds.
For farmers dealing with tough weeds such as Palmer amaranth, waterhemp and other pigweed species, the news is significant. While none of the new products is available for use yet, several are moving closer to commercialization after years of research and regulatory review.
The Weed Science Society of America (WSSA) praised EPA’s actions, noting that new herbicide technologies are critical as herbicide-resistant weeds continue to spread across U.S. crop acres.
Two New Active Ingredients Closest to Market
Among the six technologies, EPA issued final registration decisions — subject to a 60-day public comment period — for two new herbicide active ingredients: epyrifenacil and diflufenican.
Valent’s Rapidicil (Epyrifenacil)
Valent is developing the active ingredient epyrifenacil under the trade name Rapidicil, a fast-acting PPO inhibitor designed for preplant burndown applications and cover crop termination.
The chemistry is intended for use in field corn, soybeans, wheat, canola, fallow ground and non-crop areas.
Valent expects its first commercial products containing epyrifenacil — Empera and Empera Viragess — to become available in late 2026. The active ingredient was developed by Sumitomo Chemical Co., Valent’s parent company.
Bayer’s Convintro (Diflufenican)
Bayer is developing Convintro, a Group 12 preemergence herbicide containing diflufenican, for use in corn and soybeans.
The herbicide is designed to provide broad-spectrum residual control of broadleaf weeds, including herbicide-resistant waterhemp, Palmer amaranth and other pigweed species.
Although EPA registration is a major milestone, Convintro must still receive approval from individual state regulatory agencies before it can be sold. Bayer expects availability to vary by state, with commercial launches beginning during the 2027 growing season.
Four More Technologies In The Works
In addition to epyrifenacil and diflufenican, EPA advanced four other herbicide technologies that remain at different stages of the development and registration processes.
They include:
- BASF isoxaflutole is a pre-plant/pre-emergence Group 27 herbicide designed to control over 70 tough grass and broadleaf weeds. It is currently used in corn and soybeans and is under development for the cotton market.
- BASF topramezone, a Group 27 HPPD inhibitor for controlling broadleaf weeds, including Palmer amaranth and other pigweeds. It is being developed for new use in Axant Flex topramezone-resistant cotton.
BASF trifludimoxazin, a systemic Group 14 protoporphyrinogen oxidase (PPO) inhibitor herbicide that targets both broadleaf and grassy weeds in crops including soybeans, corn, and cereals. It is notable for controlling PPO-resistant weed populations and providing both pre-emergent and burndown control, according to the WSSA.
The EPA originally approved trifludimoxazin in 2021, but after facing a lawsuit from environmental groups over endangered species protections, BASF voluntarily paused development of the chemistry in early 2022 but has resumed the registration process.
- Corteva florpyrauxifen-benzyl is being developed for use in residentrial turf, commercial sports, sod farms and turfgrass areas. Currently, it is branded as Rinskor in the U.S. and is primarily used in rice, small grains and pastures.
Some of these products are closer to commercialization than others, and companies must still complete remaining federal and state regulatory requirements before farmers can purchase them.
Industry Groups Applaud EPA Efforts
Farm organizations welcomed EPA’s actions, saying farmers need additional herbicide options as resistant weeds become more widespread.
The American Farm Bureau Federation said new registrations provide growers with valuable tools to manage increasingly difficult weed pressure while maintaining crop productivity.
“We appreciate EPA’s rigorous review process and ultimate approval of new products that will help farmers grow crops for food, fiber and renewable fuel while also contributing to sustainability goals,” AFBF President Zippy Duvall said in a statement.
Environmental Groups Level Criticism At EPA
Environmental organizations quickly criticized EPA’s actions, arguing the agency is moving too aggressively to expand access to pesticides.
Groups including the Center for Food Safety and the Center for Biological Diversity said approvals covering several pesticide active ingredients — including epyrifenacil, diflufenican, fluoxapiprolin and trifludimoxazin, along with expanded uses for chlormequat chloride and bifenthrin — could pose environmental and public health risks.
An article published by the Center for Biological Diversity also contends that epyrifenacil and diflufenican should be considered PFAS, commonly referred to as “forever chemicals.” EPA says neither product meets the agency’s current regulatory definition of PFAS.
What Farmers Should Expect In Future Labels
While new herbicide technologies are welcome additions to weed management programs, growers should also expect increasingly complex product labels.
Future registrations are expected to include additional environmental requirements, including spray drift mitigation measures, runoff reduction practices and endangered species protections.
For farmers battling resistant weeds, however, the arrival of new herbicide chemistries offers another opportunity to diversify their weed control programs and preserve the effectiveness of existing products in the marketplace.
