Press Release •  11/6/2018

Corteva Agriscience™, Agriculture Division of DowDuPont, Submits New Pasture Herbicide to EPA

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Product Promises New Chemistry, Pending Registration

INDIANAPOLIS — Corteva Agriscience, Agriculture Division of DowDuPont, submitted a new herbicide for broadleaf weed control on pastures and rangeland to the U.S. Environmental Protection Agency (EPA). Pending EPA registration, this herbicide will provide cattle producers access to a broader spectrum weed control product, compared with current market standards. This will be first new active ingredient for pastures and rangeland in more than 10 years.

“Regardless of market conditions, it’s always a good idea in the cattle business to focus on the forage production and quality side of the equation,” explains Damon Palmer, Pasture and Land Management Leader at Corteva Agriscience. “Effective weed control can help producers get greater productivity from their lowest-cost feed source — grazing land — and maximize their return on their investment.”

Multiple years of testing show improved control of important broadleaf species, including wild carrot, giant hogweed, wild parsnip, poison hemlock and common caraway, plus better late-season control of marshelder and ironweed. It brings Rinskor® active, recipient of the 2018 Presidential Green Chemistry Challenge Award, to pasture management, along with a number of anticipated features, including:

  • Safe to desirable forage grasses
  • Season-long residual control
  • Low use rate
  • Compatibility with dry and liquid fertilizer
  • A low-odor formulation

“Tall ironweed is the number one weed problem in beef cattle pastures in our area,” explains William W. Witt, emeritus professor, Plant and Soil Sciences at the University of Kentucky. “It reduces forage production, and cattle avoid grazing around it. So, it reduces available grazing area.”

Witt conducted multiple trials over several years with this new pasture herbicide. Tall ironweed control exceeded 90 percent, one year after treatment. He says the potential for better late-season control would benefit producers.

“Tall ironweed is a deep-rooted perennial, so we need a highly effective herbicide,” Witt said. “When weather or the busyness of the spring prevent early pasture spraying, a wider treatment window would be helpful.”

Pending EPA registration, Corteva Agriscience expects this to be the second of three products brought to the pasture market over the next three years.

“Earlier this fall, we introduced MezaVue herbicide as the new standard in pricklypear control,” Palmer said. “Corteva Agriscience is focused on working with cattle producers to help them meet their individual goals for their land -- that is a significant objective for us. In addition to our legacy brands, including GrazonNext HL, Chaparral and PastureGard HL herbicides, we are committed to researching and developing new, simple solutions for ranchers across the country. We are excited about bringing these new products to market.”

Corteva Agriscience anticipates announcing the brand name for this new pasture herbicide in 2019.

Ironweed can limit forage production and pasture utilization.


Poison hemlock leaf.jpg
Poison hemlock is a growing challenge for cattle producers.


About Corteva Agriscience, Agriculture Division of DowDuPont

Corteva Agriscience, Agriculture Division of DowDuPont (NYSE: DWDP), is intended to become an independent, publicly traded company when the previously announced spinoff is complete by June 2019. The division combines the strengths of DuPont Pioneer, DuPont Crop Protection and Dow AgroSciences. Corteva Agriscience provides growers around the world with the most complete portfolio in the industry — including some of the most recognized brands in agriculture: Pioneer®, Encirca®, the newly launched Brevant Seeds, as well as award-winning Crop Protection products — while bringing new products to market through our solid pipeline of active chemistry and technologies. More information can be found at

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Label precautions apply to forage treated with GrazonNext HL or Chaparral and to manure from animals that have consumed treated forage within the last three days. Consult the label for full details.


™®Trademarks of Dow AgroSciences, DuPont or Pioneer, and their affiliated companies or their respective owners. This new product has not yet received regulatory approvals; approvals are pending. The information presented here is not an offer for sale. MezaVue is a Restricted Use Pesticide. MezaVue, Rinskor, GrazonNext HL and Chaparral are not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions.


Kacey Birchmier
DuPont Agriculture

Erik Johnson
Bader Rutter