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Evaluation of Glyphosate-Tolerant and Conventional Alfalfa Weed Control Systems during the First Year of Establishment

Published online by Cambridge University Press:  20 January 2017

Robert G. Wilson  and
Paul A. Burgener
Robert G. Wilson*
Affiliation:
Department of Agronomy and Horticulture and Research Analyst, Department of Agricultural Economics, University of Nebraska–Lincoln, Scottsbluff, NE 69361
Paul A. Burgener
Affiliation:
Department of Agronomy and Horticulture and Research Analyst, Department of Agricultural Economics, University of Nebraska–Lincoln, Scottsbluff, NE 69361
*
Corresponding author's E-mail: rwilson@unl.edu.
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Abstract

A field trial was conducted for 3 yr (2005 through 2007) near Scottsbluff, NE, to examine weed control, crop safety, forage production, and economics of glyphosate-tolerant and conventional alfalfa establishment systems. Glyphosate applied to alfalfa at the unifoliate growth stage provided 67% weed control and was similar to imazamox applied at the two-trifoliate leaf stage. Delaying glyphosate application until alfalfa had reached the two-trifoliate growth stage improved weed control to 83%, and weed control was similar to imazamox plus 2,4-DB and imazethapyr plus 2,4-DB. Imazamox and imazethapyr caused minor crop injury, and the addition of bromoxynil or 2,4-DB to both herbicides further decreased crop safety. Weeds were most competitive with the first forage harvest and reduced relative feed value, crude protein, and value (dollars per t) of forage compared to forage that had been treated with herbicides. The total forage yield for the season consisted of three forage harvests and was greatest when no herbicides were applied. The total forage yield of plots treated with glyphosate at the two-trifoliate growth stage was greater than that of plots treated with imazamox or imazethapyr in combination with bromoxynil. When glyphosate was applied at the two-trifoliate growth stage, seasonal forage yield was similar to forage treated with imazamox, imazethapyr, or both herbicides in combination with 2,4-DB. When herbicide was applied to alfalfa at the two-trifoliate growth stage, the net return from using glyphosate with a glyphosate-tolerant alfalfa variety or utilizing imazamox with a conventional alfalfa variety were similar at $742 and $743/ha, respectively.

Keywords

2,4-DBbromoxynilglyphosateimazamoximazethapyralfalfa, Medicago sativa L. ‘RR04BD-2411’, ‘Rebound 4.2’Herbicide-tolerant cropsforage qualityweed management
Type
Weed Management—Other Crops/Areas
Information
Weed Technology , Volume 23 , Issue 2 , June 2009 , pp. 257 - 263
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Anonymous. Livestock and Grain Market News 2008. USDA Agriculture Marketing Service. http://marketnews.usda.gov/portal/lg. Accessed: March 5, 2008.Google Scholar
Becker, R. L., Shaeffer, C. C., Miller, D. W., and Swanson, D. R. 1998. Forage quality and economic implications of systems to manage giant foxtail and oat during alfalfa establishment. J. Prod. Agric 11:300–308.Google Scholar
Canevari, W. M., Orloff, S. B., Vargas, R. N., and Hembree, K. J. 2003. Raptor, a new herbicide for alfalfa weed control. Proc. Calif. Weed Sci. Soc 55:107–111.Google Scholar
Cords, H. P. 1973. Weeds and alfalfa hay quality. Weeds 21:400–401.Google Scholar
Curran, B. S., Kephart, K. D., and Twidwell, E. K. 1993. Oat companion crop management in alfalfa establishment. Agron. J. 85:998–1003.Google Scholar
Fischer, A. J., Dawson, J. H., and Appleby, A. P. 1988. Interference of annual weeds in seedling alfalfa (Medicago sativa). Weed Sci 36:583–588.Google Scholar
Gomez, K. A. and Gomez, A. A. 1984. Statistical Procedures for Agricultural Research. New York: Wiley. 680.Google Scholar
Hintz, R. W. and Albrecht, K. A. 1991. Prediction of alfalfa chemical composition from maturity and plant morphology. Crop Sci 31:1561–1565.Google Scholar
Jeranyama, P. and Garcia, A. D. 2004. Understanding relative feed value (RFV) and relative forage quality (RFQ). South Dakota State University Extension Bulletin 8149. 3.Google Scholar
Jose, H. D. and Malchow, S. 2006. 2006 Nebraska Farm Custom Rates—Part I. Cooperative Extension Circular EC823. Lincoln, NE: University of Nebraska. 10.Google Scholar
Marten, G. C. and Andersen, R. N. 1975. Forage nutritive value and palatability of 12 common annual weeds. Crop Sci 15:821–827.Google Scholar
McCarty, M. K. and Sand, P. F. 1961. Chemical weed control in seedling alfalfa. III. Effect of some herbicides on five varieties. Weeds 9:14–19.Google Scholar
McCaslin, M., Fitzpatrick, S., and Temple, S. 2000. Roundup ready alfalfa: progress report. Pages 245. in. Proceedings of the 29th National Alfalfa Symposium and 30th California Alfalfa Symposium, Las Vegas, NV. Davis, CA: Department of Agronomy and Range Science Cooperative Extension, University of California.Google Scholar
McCordick, S. A., Hillger, D. E., Leep, R. H., and Kells, J. J. 2008. Establishment systems for glyphosate-resistant alfalfa. Weed Technol 22:22–29.Google Scholar
Nelson, K. A., Renner, K. A., and Penner, D. 1998. Weed control in soybean (Glycine max) with imazamox and imazethapyr. Weed Sci 46:587–594.Google Scholar
Orloff, S. B., Vargas, R. N., Canevari, W. M., and Hembree, K. J. 2003. Progress in Roundup Ready alfalfa. Pages 112–116. in. Proceedings for the 33rd California Alfalfa & Forage Symposium, Monterey, CA. Davis, CA: Department of Agronomy and Range Science Cooperative Extension, University of California.Google Scholar
Peregrine, E. K. and Norris, R. F. 1988. Environmental modification of seedling alfalfa, Medicago sativa, tolerance to bromoxynil. Weed Sci 36:671–677.Google Scholar
Selley, R. A., Barrett, T., Klein, R. N., Hay, P., Holman, T., Jarvi, K., Seymour, R., and Zoubek, G. 2006. Nebraska Crop Budgets. Cooperative Extension Circular EC06-872-S. Lincoln, NE: University of Nebraska. 42.Google Scholar
Simmons, S. R., Sheaffer, C. C., Rasmusson, D. C., Stuthman, D. D., and Nickel, S. E. 1995. Alfalfa establishment with barley and oat companion crops differing in stature. Agron. J. 87:268–272.Google Scholar
Tonks, D., Jeffery, L. S., and Webb, B. L. 1991. Response of seedling alfalfa (Medicago sativa) to four postemergence herbicides. Weed Technol 5:736–738.Google Scholar
University of Nebraska 2007. 2007 Guide for Weed Management in Nebraska Cooperative Extension Circular EC130. Lincoln, NE: University of Nebraska. 192.Google Scholar
Ward, C. E. 1994. Price and quality relationships for alfalfa hay. J. Am. Soc. Farm Manag. Rural Appraisers 58:130–134.Google Scholar
Wilson, R. G. 1986. Weed control in irrigated seedling alfalfa (Medicago sativa). Weed Sci 34:43–426.Google Scholar
Wilson, R. G. 1994. Effect of imazethapyr on legumes and the effect of legumes on weeds. Weed Technol 8:536–540.Google Scholar