|Clenet, Danielle - Oregon State University|
|Johnson, Dustin - Oregon State University|
|Kerby, Jay - Nature Conservancy|
Submitted to: Restoration Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2019
Publication Date: N/A
Interpretive Summary: Revegetation of exotic annual grass-invaded rangeland with pre-emergent herbicides is challenging because seeding is delayed until herbicide toxicity has diminished, but at this time, exotic annuals can be re-invading. Incorporating seeds into activated carbon pellets may protect seedlings from pre-emergent herbicide damage because activated carbon can neutralize the herbicides around the seedling. We evaluated using activated carbon pellets with a native grass and shrub seeded at the same time indaziflam was applied at four rates in a grow room study. Activated carbon pellets protected seeded species at low, mid, and high rates of indaziflam. These results suggest that activated carbon pellets can be used to seed native grasses and shrubs simultaneously with indaziflam application.
Technical Abstract: Reestablishing native perennial vegetation in annual grass-invaded rangelands is critical to restoring ecosystems. Control of exotics, often achieved with pre-emergent herbicides, is essential for successful restoration of invaded rangelands. Unfortunately, desirable species cannot be seeded simultaneously with pre-emergent herbicide application due to non-target damage. To avoid this, seeding is commonly delayed at least one year. Delaying seeding increases the likelihood that annual grasses will begin reestablishing and compete with seeded species. Activated carbon (AC) can provide pre-emergent herbicide protection for seeded species because it adsorbs and deactivates herbicides. Previous studies suggest that a cylindrical herbicide protection pod (HPP), containing AC and seeds, allows desired species to be seeded simultaneously with the application of the pre-emergent herbicide imazapic. Unfortunately, imazapic is only effective at controlling annual grasses for 1-2 years. Indaziflam is a new pre-emergent herbicide which exhibits longer soil activity, with which HPPs may be useful. To assess this possibility, we evaluated seeding two native species (Wyoming big sagebrush (Artemisia tridentata Nutt Spp. wyomingensis) and bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) Á. Löve)), both incorporated into HPPs and as bare seed, at four application rates of indaziflam in a grow room study. HPPs protected seeded species at low, mid, and high rates of indaziflam. The abundance and size of plants was greater in HPPs compared to bare seed treatments. These results suggest that HPPs can be used to seed native grasses and shrubs simultaneously with indaziflam application.