Plant cover and density and sagebrush growth in Idaho roadsides treated with herbicides and bioherbicides

Proliferation of cheatgrass and other exotic annual grasses such as medusahead and ventenata are a major environmental concern and operational problem for roadsides in Idaho. These annual grasses are highly flammable and they shorten fire-return intervals. Flammable vegetation is particularly hazardous in roadsides because of proximity to a ready source of ignition, and fires that start on roadsides can spread into adjacent public lands and urban communities with sprawling home development, causing extensive and expensive damage and degradation to wildlife habitat, rangelands, private or public property, utilities, etc. Thus, the Idaho Transportation Department (ITD) has a strong interest in preventing roadside vegetation from becoming invaded by exotic annual grasses and in improving vegetation on roadsides that are currently invaded, replacing exotic annual grasses with perennial bunchgrasses and forbs that support pollinators. These data were generated in roadside tests of various tools designed to reduce exotic annual grasses on the landscape, as well as techniques designed to improve the efficacy of these tools. These include the ACK55 strain of the bacterium Pseudomonas fluorescens, which was isolated to target cheatgrass, medusahead and jointed goatgrass (aka “weed-suppressive bacteria”, hereafter “WSB”). We also tested a relatively new pre-emergent herbicide, indaziflam (Rejuvra®) thought to remain active in soil for years after application. We tested these against and in combination with the “workhorse” pre-emergent herbicide most frequently sprayed by land managers for exotic annual grass control, Imazapic (Plateau®).

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  "010:12"
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  "geospatial"
]