ARS | Publication request: Herbicides for Establishing Switchgrass in the Great Plains

Submitted to: Asa-Cssa-Sssa Annual Meeting Abstracts
Publication Acceptance Date: August 10, 2003
Publication Date: October 1, 2004
Citation: Mitchell, R., Vogel, K.P., Masters, R.A., Berdahl, J.D. 2004. Herbicides For Establishing Switchgrass In The Great Plains. Agronomy Abstracts. Cd-Rom No. 4505. Asa, Cssa Sssa. Madison, Wi.

Technical Abstract: Our objective was to determine the effect of selected herbicides applied at seeding on stand establishment and subsequent biomass yields of switchgrass in the Northern Great Plains. 'Cave-In-Rock' and 'Trailblazer' were planted in May 2000 at Mead, NE, Highmore, SD, and Mandan, ND. Additionally, 'Sunburst' was planted at Highmore and 'Forestberg' was planted at Mandan. Herbicides applied immediately after planting were different concentrations of atrazine, quinclorac, atrazine + quinclorac, imazapic, and quinclorac + imazapic. Herbicide efficacy was determined by measuring stand frequency of occurrence and biomass yield. In the year after establishment, imazapic often reduced switchgrass stands in comparison to the untreated control, and is not recommend by the manufacturer for switchgrass establishment. The other herbicides did not reduce stands at any of the locations. Herbicide treatments impacted post-establishment year biomass yields only at Mead. Plots treated with atrazine + quinclorac produced 7.4 Mg/ha of switchgrass biomass. The herbicide by cultivar interaction was not significant for stands or biomass yields, indicating that the effects of herbicides on switchgrass stands and biomass yields are consistent over cultivars. The application of atrazine + quinclorac resulted in acceptable stands and high biomass yields, and appears to be an excellent herbicide combination for establishing switchgrass for biomass production in the Great Plains.