NAAA Submits Comments to EPA on Fungicide Strategy, Aquatic Buffer Zones, and Drone Drift Data
Last week NAAA submitted comments to the EPA on its draft fungicide strategy. The strategies (herbicide, insecticide, and now fungicide) are EPA’s blueprints detailing how they will assess the risk of pesticides to endangered species and their critical habitats during the registration of new pesticides and when older pesticides get reviewed. The final herbicide strategy was released in August of 2024, followed by the insecticide strategy in June of 2025. EPA’s endangered species strategies are part of their ongoing efforts to become compliant with the Endangered Species Act (ESA) and settle numerous lawsuits against the agency regarding their past efforts to address ESA in their registration activities.
The majority of the components that involved aerial applications from the insecticide strategy remained unchanged in the draft fungicide strategy. Wind-directional spray drift buffer zones from 50 to 300 feet will be used to mitigate the risk of drift from aerial applications. The exact distance will be based on the risk the specific pesticide being assessed poses to endangered species. Managed areas count as part of the buffer zone, and the required distance can be reduced by using drift mitigation options. For a thorough review of how EPA’s endangered species strategies will impact aerial applicators, NAAA recommends members review the 2025-2026 PAASS program.
One change for aerial applicators is that the fungicide strategy adds oil emulsion drift reduction adjuvants as a mitigation option to reduce buffer distance for both fungicides and insecticides, not just herbicides. Ground applicators received the ability to use guar gum drift reduction adjuvants to reduce buffer distance; aerial applicator did not get this option. NAAA informed EPA they will be working with the USDA-ARS Aerial Application Technology Research Unit (AATRU) to collect wind tunnel data on the impact guar gum adjuvants have on the droplet size for aerial applications. EPA is also considering how fungicides may impact endangered vertebrates who eat seeds treated with fungicides or are exposed directly to a fungicide application. NAAA recommended they ensure any potential mitigations do not prevent crops from receiving timely fungicide applications.
NAAA also submitted comments to EPA on buffer zones to protect aquatic areas. These comments were focused on those labels that still have mandatory buffer zones that are required on all sides of aquatic areas, regardless of wind direction. NAAA recommended EPA implement these buffer zones in the same manner as endangered species buffer zones – they should not be required when wind is blowing away from an aquatic area, and managed areas and mitigation options should be able to reduce the buffer distance.
NAAA’s final comments submitted to the EPA dealt with how drift data submitted to the EPA by the Unmanned Aerial Pesticide Application System Task Force (UAPASTF) compared their spray drift results to that of manned agricultural aircraft. UAPASTF compared the results of field trial data from four passes with a drone to the Tier 1 AgDRIFT model. NAAA took issue with that comparison, reminding the EPA they now recognize the Tier 3 AgDRIFT model with modern assumptions as a more accurate model for aerial applications. Additionally, the Tier 3 AgDRIFT model assumes the area is treated with 15 passes using an AT-802, not 4 passes with a drone that has a much narrower swath width. NAAA asked that EPA consult with scientists from AATRU in order to accurately assess the data and make valid comparisons between drones and other application platforms.
NAAA’s comments can be read at the following locations: