B08_-_Airport_PUP_ORW030-26-005-PUP.pdf

This is a Pesticide Use Proposal submitted by the Bureau of Land Management (BLM) Spokane District for herbicide treatments on approximately 1,400 acres of BLM-managed land in Lincoln County, Washington. The proposal covers the period 2026-2029 and was prepared by Jonathan Carvella, Border Field Office Botanist, with approval dated April 28, 2026 (Proposal Number ORW030-26-001).

The treatment area is located in the Airport pasture of the Fishtrap allotment northeast of Sprague, Washington, and is designed to mitigate wildfire risk and manage noxious weeds and invasive annual grasses. Proposed herbicides include Imazapic products (Alligare Panoramic 2SL, Nufarm Imazapic 2SL, and Plateau) at rates up to 12 oz/acre with active ingredient up to 0.19 lb a.e./acre, and Aminopyralid products (Milestone and Whetstone) at rates up to 7 oz/acre with active ingredient up to 0.11 lb a.e./acre. Application methods include spot spraying via backpack and truck/UTV-mounted sprayers, as well as broadcast application via aerial (fixed-wing aircraft and rotorcraft) and ground-mounted boom nozzles. Multiple adjuvant products are approved for use, including surfactants, oils, and defoaming agents. Imazapic applications will occur between October 1 and April 1 annually, while Aminopyralid applications will occur between March 15 and October 31 annually, with typically one application per herbicide per year. The desired outcome is to reduce cover of target invasive species (Bromus tectorum, B. japonicus, B. arvensis, and Ventenata dubia) to less than 5% within one year post-treatment, thereby improving rangeland health and reducing wildfire fuel continuity. The proposal was approved with modifications by the BLM State Pesticide Coordinator on May 19, 2026.