Aerial spraying for invasive weeks wraps up early

NORTH FORK, Idaho (KIFI) — Aerial spraying contractors wrapped up operations on the North Fork Ranger District Saturday after applying herbicides on all units contracted for treatment this year. 

Moderate temperatures and relatively low winds during the first two weeks of the five-week herbicide application window allowed crews to treat 11,000 acres of National Forest System lands for annual invasive species.

“The fall is the best time to effectively treat these noxious weeds before they sprout,” District Ranger. Chris Waverek said. “With the use of helicopters, we were able to be efficient and accurate with the application of herbicide."

Salmon-Challis has been aerially applying herbicides to National Forest System lands every fall since 2018. The applications are part of the Forestwide Integrated Weed Management Project, the environmental impact statement for which was completed in 2016.

The herbicides used in these aerial operations are Milestone and Plateau, both of which are plant growth hormone regulators designed to interrupt and halt development of invasive annual grasses, such as cheatgrass and spotted knapweed. According to Botany, Invasives, and Pollinators Program staff, Milestone and Plateau are both recognized as having low use rates, little to no toxicity to humans, low toxicity to non-target organisms, and low potential for groundwater contamination.

An unexpected aspect of this year’s applications was that one of the units scheduled for treatment included an area that burned during the Moose Fire earlier this summer.  While forest specialists have been corresponding with research scientists to determine the most effective way to treat burned areas following the Moose Fire, areas targeted for this project have not previously included burned areas. 

Salmon-Challis staff said they look forward to the what the data they collect next spring can tell them about how to prevent re-emergence of noxious weeds after wildland fire so native vegetation has a better chance to re-establish.