NAAA Submits Comments to EPA in Support of Aerial Application for Two Herbicides

NAAA recently submitted comments to the EPA for two different herbicides. The first was directed towards the registration of epyrifenacil, a new herbicide for use as a pre-plant burndown herbicide for agricultural use in canola, field corn, soybean, wheat, and fallow land. It will also be labeled for some non-crop sites, including guardrails, railroads, parking areas, road surfaces and shoulders. Aerial application of epyrifenacil on non-crop sites will be prohibited; NAAA did not object to this non-crop prohibition as none of these use sites are typically applied to with ag aircraft.

NAAA agreed with most of the proposed mitigations for aerial applications of epyrifenacil including droplet size, boom length restrictions, maximum wind speed, swath displacements, wind measurement, release height, buffer zones for unmanaged areas, and the use of EPA’s online mitigation menu to reduce buffer distance. NAAA objected to the vague statement “When applying to crops via aerial application equipment, the spray boom must be mounted on the aircraft to minimize drift caused by wing tip or rotor blade vortices.” NAAA requested a discussion with EPA to determine exactly what EPA intends with this statement. NAAA also objected to the proposed minimum spray application rate of seven gallons per acre (GPA). NAAA detailed how increasing GPA with straight steam nozzles can increase the risk of drift. Click here to read NAAA’s full comments on epyrifenacil.

The second herbicide NAAA commented on was atrazine. At the end of September, the Fish and Wildlife Service (FWS) released their draft biological opinions (BiOp) for atrazine and simazine. Biological opinions are the final stage of the consultation between EPA and FWS regarding endangered species protection before finalizing a pesticide’s re-registration. Since aerial application of simazine is already prohibited, NAAA focused on atrazine. The atrazine BiOp used the herbicide strategy to develop mitigations for aerial applications of atrazine to protect endangered species. NAAA agreed with almost all proposed mitigations, including droplet size, boom length restrictions, maximum wind speed, swath displacements, release height, and downwind buffer zones for protected areas. NAAA did object to the prohibition of aerial application for all dry formulations of atrazine; this prohibition is due to human exposure risks for mixers and loaders and is unlikely to be changed. Click here to read NAAA’s full comments on atrazine.