Comment Period Opens for Liberty ULTRA

JEFFERSON CITY, Mo. (DTN) -- On Thursday, May 9, EPA released for public comment its proposed registration decision for products containing glufosinate-P, the active ingredient in BASF's Liberty ULTRA herbicide. The public comment period will be open for 30 days, closing on June 8.

The proposed registration includes uses to control weeds in non-tolerant and glufosinate-resistant corn, sweet corn, soybean, cotton and canola. When announcing Liberty ULTRA in August 2023, BASF said the product is intended to control both grasses and broadleaf weed species such as waterhemp, Palmer amaranth, giant ragweed and kochia.

Glufosinate-P is an isomer of the currently registered herbicide glufosinate. It is a non-selective herbicide that kills plants by causing excess ammonia build-up and directly inhibiting photosynthesis.

EPA said it received applications for both glufosinate-P and its ammonium salt, glufosinate-P ammonium. Both will generally exist in the same form in the environment and share the same herbicidal properties, the agency stated, so it considers glufosinate-P to be the active ingredient under the proposed registration decision.

EPA noted that glufosinate-P has similar benefits and uses to currently registered glufosinate herbicide products. These benefits include flexible application timing, which allows for postemergence weed control "over the top" of glufosinate-tolerant crops and for early season use in non-tolerant crops.

While the EPA is proposing to register several glufosinate-P and glufosinate-P-ammonium products for manufacturing and commercial distribution, Liberty ULTRA headlines the list.

In its announcement of the product, BASF said the herbicide is "powered by Glu-L Technology," which removes the inactive D isomer and concentrates the herbicidally active L isomer. This enables a 25% rate reduction compared to other glufosinate products, packing "the power of 32 fluid ounces of Liberty herbicide into a convenient 24 fluid ounces of Liberty ULTRA," according to the company.

BASF claims Liberty ULTRA locks more droplets onto weed leaves for better leaf coverage with every pass. Once the leaf is covered, the proprietary formulation also has been shown to drive nearly three times more herbicide into weeds when compared to generic glufosinate products, the company said.

EPA acknowledged that the proposed glufosinate-P products result in fewer chemicals entering the environment, stating that glufosinate-P applications require approximately half the application rate compared to glufosinate.

Before issuing this proposed registration decision, EPA evaluated the potential hazardous effects and exposures to human health and the environment, as required by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Based on the agency's human health risk assessment, the proposed uses of glufosinate-P have no human health risks.

The federal agency also noted that its action complies with its obligations under the Endangered Species Act (ESA). EPA is proposing several mitigation measures to reduce exposure to non-target species, minimizing impacts to federally endangered and threatened species and their designated critical habitats. EPA said glufosinate-P is the fourth new conventional active ingredient the agency has proposed to register that complies with the ESA.

After considering public comments on the proposed registration and the draft effects determinations, EPA will determine whether the registration action meets both the FIFRA standard and ESA obligations. If EPA determines that the registration action can be granted, the agency will finalize the biological evaluation.

If a final biological evaluation continues to find that glufosinate-P may affect any listed species or critical habitats, then EPA will initiate ESA consultation and share its findings with the U.S. Fish and Wildlife Service or the National Marine Fisheries Service (collectively referred to as the Services), as appropriate.

During any formal consultation, the Services use the information in EPA's final biological evaluation to inform their biological opinions. While EPA has made predictions about the potential likelihood of future jeopardy/adverse modification as part of its biological evaluation, the Services are responsible for making the actual final jeopardy/adverse modification findings and have the sole authority to do so.

If the Services determine in their final biological opinions that additional mitigations are necessary to address any jeopardy/adverse modification determination or to address any unintentional harm known as incidental take, then EPA will work with the registrant to ensure that any necessary registration or labeling changes are made.

To read more about the proposed registration of glufosinate-P and to comment, go here: https://www.regulations.gov/…

The last day to submit a comment is June 8, 2024.

Jason Jenkins can be reached at jason.jenkins@dtn.com

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