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The Center for Native Grasslands Management

Title: Using imazapic and prescribed fire to enhance native warm-season grasslands in Kentucky, USA
Year: 2002
Author(s): Washburn, B. E., Barnes, T. G., Rhoades, C. C., Remington, R.
Source Title: Natural Areas Journal
Source Type: Journal
pages: 20-27
Original Publication: http://  
Abstract: Tall fescue (Festuca arudinacea Shreb.) is an exotic cool-season grass that aggressively invades native grassland communities in the eastern and central United States, reducing native plant cover and botanical diversity. We conducted two studies in Kentucky to determine the usefulness of post-emergence herbicide applications for eradicating tall fescue and increasing native warm-season grasses. In one study, we applied imazapic (0.21 kg active ingredient ha(-1)) to three previously planted native warm-season grass stands in April 1998 and evaluated tall fescue and seeded native grass cover in fall 1998. Tall fescue cover was reduced to less than 10% in most treatment plots. Mean native warm-season grass cover increased from 30% to 100% following herbicide application. In a second study, we evaluated prescribed burning and post-emergence imazapic applications (0.07-0.18 kg active ingredient ha(-1), with and without non-ionic surfactant) for tall fescue control and increasing native warm-season grasses and native forbs in remnant native barrens plant communities. Prescribed burning in spring followed by a post-emergence application of imazapic at 0.14 or 0.18 kg active ingredient ha(-1) with or without non-ionic surfactant reduced tall fescue cover to less than 25% and increased native grass cover by 18% to 50% in all treatment plots. Imazapic at 0.18 kg active ingredient ha(-1) and nonionic surfactant (without prescribed burning) was also effective. Cover of Indiangrass (Sorghastrum nutans [L.] Nash), big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachryrium scoparium [Michx.] Nash), broomsedge bluestem (Andropogon virginicus L.), and tall dropseed (Sporobolus asper [Michx.] Kunth) increased in the herbicide treatments. Imazapic may be a useful tool for removing tall fescue and enhancing native warm-season grasses and native forbs in planted stands and in native barrens ecosystems.