Assessing commercially produced herbicide protection seed coatings and the effects of seeding strategy and added biostimulant film coating
Invasive annual plants hinder restoration across dryland ecosystems, and pre‑emergent herbicides often provide only temporary control. This study tested refined herbicide‑protection (HP) seed coatings for two perennial bunchgrasses and one shrub using laboratory and multi‑site field trials across the sagebrush ecosystem of western North America. Activated‑carbon HP coatings consistently protected seeds from herbicide exposure, improving first‑year seedling density and two‑year adult establishment for multiple species. Biostimulant film coatings showed no added benefit, while deep‑furrow seeding after herbicide application enhanced establishment and strengthened HP effects for one grass species. Results indicate that HP seed technology can meaningfully improve restoration outcomes at landscape scales where herbicides are required to suppress invasive annuals.
Subject Tags
- Grassland
- Invasive Species
Abstract
Exotic invasive plant species threaten biodiversity, ecosystem resilience, and ecological function. Pre-emergent herbicides are popular tools for managing invasive annual plants, but control is often temporary. Herbicide protection (HP) seed technologies have been under development to improve the success of seed-based restoration efforts in invasive-dominated areas by establishing desirable plants concurrently with controlling exotic plants using pre-emergent herbicide. Many HP prototypes have been tested in a dryland restoration context, and many assessments suggest additional refinements to improve the technologies and approaches. Using laboratory and geographically dispersed field trials in the sagebrush ecosystem of western North America, we assessed the performance of refined HP seed coatings for two perennial bunchgrasses and one shrub against uncoated bare seed with powdered activated carbon dust and uncoated bare seed without activated carbon. We specifically tested whether an added biostimulant film coating (laboratory trial) and different seeding strategies (field trial) affected outcomes. The laboratory trial demonstrated HP for all activated carbon treatments (especially powdered activated carbon), and no effects of the biostimulant film coating. The field trial also demonstrated HP of the HP activated carbon coating in the form of higher first-year seedling density of one grass and one shrub species, and higher density of surviving adults for both grass species after two years. Seeding into deep furrows made after herbicide application often improved initial establishment for all species and enhanced HP for one grass species, compared to shallow furrows applied before herbicide. Adult establishment from HP coatings (but not other treatments) was high enough to suggest that future large-scale use of HP seed technology could be a viable tool for improving landscape-scale restoration outcomes in the presence of herbicide.
Citation
Baughman, O., Kildisheva, O., Duquette, C., Boyd, C., Eshleman, M., Owens, M., ... & Schroeder, C. (2025). Assessing commercially produced herbicide protection seed coatings and the effects of seeding strategy and added biostimulant film coating. Restoration Ecology, e70149. https://doi.org/10.1111/rec.70149
TNC Authors
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Owen Baughman
The Nature Conservancy -
Olga Kildisheva
The Nature Conservancy -
Cameron Duquette
Rangeland Scientist, Oregon
The Nature Conservancy
Email: cameron.duquette@tnc.org -
Maggie Eshleman
Wyoming Restoration Scientist
The Nature Conservancy
Email: maggie.eshleman@tnc.org
TNC Authors
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Michaela Owens
Wyoming Native Plant Scientist
The Nature Conservancy
Email: michaela.owens@tnc.org -
Corinna Riginos
Wyoming Science Director
The Nature Conservancy
Email: corinna.riginos@tnc.org -
Corinne Schroeder
The Nature Conservancy