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A Systems Approach for the Management of Russian Knapweed (Centaurea repens)

Published online by Cambridge University Press:  12 June 2017

Rick M. Bottoms
Affiliation:
University of Missouri-Columbia, Oregon, MO 64473
Tom D. Whitson
Affiliation:
University of Wyoming, Laramie, WY 82070

Abstract

Studies were initiated in Wyoming to determine the potential of grass competition as an alternative to repetitive herbicide treatment or other cultural practices for control of Russian knapweed. An experiment was established to evaluate the effects of five grass species, including Russian wildrye cv. ‘Bozoisky.’ Picloram, applied to Russian knapweed during the first frost, reduced Russian knapweed from an average of 80.1% live canopy cover which equates to 0% control. Untreated, unseeded checks resulted in 83.9 and 81.1% control in tilled and nontilled treated plots, respectively. Grass cover increased in untreated seeded plots from an average of 11.3 and 8.2% in tilled and nontilled plots, respectively, to 65% in tilled and 66% in nontilled plots treated with clopyralid plus 2,4-D. Grass cover also increased 69.7% in tilled and 66% in nontilled plots treated with picloram. There was no significant difference between grass varieties when compared to percent Russian knapweed cover. Reductions to zero live canopy cover of Russian knapweed were obtained with a single application of picloram. Economic feasibility thresholds were obtained from four out of five varieties, including a significant difference provided by nontilled Russian wildrye treated with picloram.

Type
Symposium
Copyright
Copyright © 1998 by the Weed Science Society of America 

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References

Literature Cited

Asay, K. H. and Morton, W. H. 1985. Hycrest Crested Wheatgrass. Logan, UT: Utah State University Bulletin. 2 p.Google Scholar
Callihan, R. H. and Evans, J. O. 1991. Weed Dynamics in Rangeland, Noxious Range Weeds. Boulder, CO: Westview Press. 466 p.Google Scholar
Carter, J. F. 1962. Part IV—Determinations of herbage production and yield. In Kenney, W. K. and Reid, J. T., eds. Pasture and Range Research Techniques. pp. 90101.Google Scholar
Feuz, B. M., Jacobs, J. J., Heed, L. J., and Whitson, T. D. 1996. The Economics of Controlling Russian Knapweed. Albuquerque, NM: Proc. West. Soc. Weed Sci. 48 p.Google Scholar
Fletcher, R. A. and Renney, A. J. 1963. A growth inhibitor found in Centaurea spp. Can. J. Plant Sci. 43:475481.Google Scholar
Lacey, C. A. 1989. Proc. Knapweed Symp. Bozeman, MT. Montana State University Extension Bull. 45. pp. 16.Google Scholar
Lacey, C. A. 1991. Noxious Weed Management Strategies, Noxious Range Weeds, Boulder, CO: Westview Press. 466 p.Google Scholar
Quimby, P. C., Brackart, W. L., Deloch, C. J., Knutson, L., and Ralph, M. H. 1991. Biological Control of Rangeland Weeds, Noxious Range Weeds. Boulder, CO: Westview Press. 466 p.Google Scholar
[USDA] United States Department of Agriculture. 1979. Rosana Western Wheatgrass, A Conservation Plant for Montana and Wyoming. Bridger, MT: Plant Materials Center Soil Conservation Service Bull. 2 p.Google Scholar
[USDA] United States Department of Agriculture. 1981. Critana Thickspike Wheatgrass, A Conservation Plant for Montana and Wyoming. Bridger, MT: Plant Materials Center Soil Conservation Service Bull. 2 p.Google Scholar