The EPA recently announced the registration of the new active ingredient glufosinate-P, which controls weeds in conventional and glufosinate-resistant field corn, sweet corn, soybean, cotton, and canola. The Agency also released its final biological evaluation for the active ingredient under the Endangered Species Act (ESA).
“Glufosinate-P is the first new active ingredient registration where EPA has used its new Herbicide Strategy Framework, released in August 2024, to inform the level of mitigation necessary to reduce exposure to listed species and critical habitat from runoff and erosion,” according to an EPA news release. “The strategy is part of EPA’s broader plan to efficiently meet its ESA obligations by standardizing mitigation and protecting listed species from herbicides, including conventional herbicides used in agriculture, which allows EPA to meet its ESA obligations for glufosinate-P faster. Based on the Herbicide Strategy mitigation menu, glufosinate-P requires a low level of mitigations to reduce spray drift and other off-field risks.”
Following the recent restriction of diacamba, glufosinate-P is reported to be an acceptable alternative, with the added benefit of offering flexible application timing, which allows for post-emergence weed control for crops that tolerate glufosinate and for early-season application in crops that are non-tolerant.
Background
“Before issuing the final 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),” the EPA’s release continues. “No human health risks of concern were identified for the uses of glufosinate-P. However, EPA’s ecological draft risk assessment identified potential risks for terrestrial and aquatic plants and chronic risk to mammals, bees, and other terrestrial invertebrates that may forage in treated fields and may be exposed to residues by consuming food exposed to off-site spray drift.”
Mitigations
The EPA is requiring the implementation of the following mitigation measures to address on- and off-field effects to non-target species, including listed species:
- Application during rainfall and when soils are saturated or above field capacity is prohibited.
- Users are required to visit the EPA’s Mitigation Menu Website before application and determine an appropriate strategy for meeting or exceeding the required number of mitigation points as specified on the label.
- A downwind buffer between the last spray row and the protection area of 50 feet (ft) for aerial application and 10 ft for ground application is required.
- Users are instructed to access and follow any applicable endangered species bulletins for the two listed species, the Spring Creek bladderpod plant and the whorled sunflower plant, from the “Bulletins Live! Two” Web-based system for all additional directions and restrictions.
“With these mitigations in place, EPA’s final biological evaluation predicts that the use of glufosinate-P will not result in a likelihood of future jeopardy of any listed species, or a likelihood of adverse modification for any designated critical habitat,” the EPA’s release adds.
“EPA has initiated ESA consultation and shared its findings with the U.S. Fish and Wildlife Service and the National Marine Fisheries Service. During formal consultation, the Services use the information in EPA’s final biological evaluation to inform their biological opinions. … 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.”
Industry pushback
“Agricultural organizations have voiced opposition to the enhanced herbicide restrictions, asserting that they will impose undue regulatory burdens on farmers reliant on conventional crop protection methods,” notes McGlinchey Stafford in a JD Supra article. “The American Soybean Association (ASA) issued a statement indicating that the additional limitations surpass previous safety determinations. Alan Meadows, an ASA director from Tennessee, remarked, ‘The EPA seems to have capitulated to pressure from environmental organizations by imposing further [ESA] restrictions on farmers.’ This development establishes a worrisome precedent for growers.
“The approval of glufosinate-P represents a significant advancement in sustainable agriculture, providing farmers with an effective tool for weed management while ensuring the protection of human health and the environment,” McGlinchey Stafford’s article continues. “As the first herbicide approved under the EPA’s new Herbicide Strategy Framework, glufosinate-P sets a precedent for future herbicide registrations aimed at balancing agricultural productivity with environmental conservation.”
All the supporting documents related to glufosinate-P are available in EPA-HQ-OPP-2020-0250. Draft labels for BASF Corporation products are available in EPA-HQ-OPP-2020-0250, and the draft labels for MITSUI Chemicals Crops and Life Solutions INC (MCCLS) products are available in EPA-HQ-OPP-2020-0533.