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Delaware Soybean Grower Survey on Glyphosate-resistant Horseweed (Conyza canadensis)

Published online by Cambridge University Press:  20 January 2017

Barbara A. Scott  and
Mark J. Vangessel
Barbara A. Scott*
Affiliation:
Department of Plant and Soil Science, Research and Education Center, University of Delaware, 16483 County Seat Highway, Georgetown, DE 19947
Mark J. Vangessel
Affiliation:
Department of Plant and Soil Science, Research and Education Center, University of Delaware, 16483 County Seat Highway, Georgetown, DE 19947
*
Corresponding author's E-mail: bascott@udel.edu
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Abstract

In November 2004, a 29-question survey was mailed to Delaware soybean growers to determine grower perceptions of glyphosate-resistant (GR) horseweed and if glyphosate applications, GR soybean usage, and management practices had been altered in lieu of the presence of resistance. A total of 213 valid responses were received. Ninety-eight percent of respondents reported planting GR soybean at some point in the last 5 yr, with 90% reporting having planted GR soybean 3 or more years. The presence of GR horseweed on-farm was reported by 38% of the respondents and 95% of those growers with GR horseweed on-farm reported implementing one or more changes in GR soybean management. The most frequent change (66% of growers) due to resistant horseweed was the application of another herbicide with a different mode of action before planting. Forty-eight percent of growers with resistance on-farm reported a $5 to $17/ha increase to manage for GR horseweed, with 28% reporting a greater than $17/ha increase. Regardless of experience with GR horseweed, approximately 80% responded that it was worthwhile to incur additional costs now to preserve glyphosate for future use. Soybean grower reliance on glyphosate has not decreased in light of GR horseweed in Delaware. Misconceptions of timing for the selection of GR horseweed biotypes and the future availability of new herbicides with different modes of action exist within the farming community.

Keywords

Glyphosatehorseweed, Conyza canadensis (L.) Cronq. ERICAsoybean, Glycine max (L.) MerrGlyphosate-resistant soybeanglyphosate-resistant horseweedsurvey
Type
Extension/Outreach
Information
Weed Technology , Volume 21 , Issue 1 , March 2007 , pp. 270 - 274
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Bernard, J. C., Pesek, J. D. Jr, and Fan, C. 2004. Delaware growers' adoption of GE soybeans in a time of uncertain U.S. adoption. Agribusiness 20:81–94.CrossRefGoogle Scholar
Bruce, J. A. and Kells, J. J. 1990. Horseweed (Conyza canadensis) control in no-tillage soybeans (Glycine max) with preplant and preemergence herbicides. Weed Technol. 4:642–647.CrossRefGoogle Scholar
Buhler, D. D. and Owen, M. D. K. 1997. Emergence and survival of horseweed (Conyza canadensis). Weed Sci. 45:98–101.CrossRefGoogle Scholar
Dauer, J., Sharpaas, O., and Mortensen, D. A. 2004. Assessing long distance seed dispersal. Proc. Northeast Weed Sci. Soc. 58:148.Google Scholar
Fan, C. 2001. An analysis of farm level effects of GE soybeans in Delaware. M.S. Thesis. Newark, DE University of Delaware. 80.Google Scholar
Heap, I. 2005. Herbicide-resistant horseweed globally. Weed Science Society of America: Web page: http://www.weedscience.org/. Accessed: September 11, 2005.Google Scholar
Llewellyn, R. S. 2002. What Australian growers will adopt in managing herbicide resistance. Proc. Aust. Weeds Conf. 13:680–684.Google Scholar
Llewellyn, R. S., Linder, R. K., Pannell, D. J., and Powles, S. B. 2001. Grower perception of the herbicide resistance ‘wall’. SEA Working Paper 01/13. School of Agriculture and Resource Economics, University of Western Australia. Web page: http://www.general.uwa.edu.au/u/dpannell/dpap0113.htm. Accessed: August 4, 2004.Google Scholar
Mueller, T. C., Mitchell, P. D., Young, B. G., and Culpepper, A. S. 2005. Proactive versus reactive management of glyphosate-resistant or tolerant weeds. Weed Technol. 19:924–933.CrossRefGoogle Scholar
Norsworthy, J. K. 2003. Use of soybean production surveys to determine weed management needs of South Carolina growers. Weed Technol. 17:195–201.CrossRefGoogle Scholar
Orson, J. H. 1999. The cost to the grower of herbicide resistance. Weed Technol. 13:607–611.CrossRefGoogle Scholar
Pannell, D. J. and Zilberman, D. 2001. Economic and sociological factors affecting growers' decision making on herbicide resistance. in Powles, S.B., Shaner, D.L., eds. Herbicide Resistance and World Grains. Boca Raton, FL CRC. 251–278.CrossRefGoogle Scholar
VanGessel, M. J. 2001. Glyphosate-resistant horseweed from Delaware. Weed Sci. 49:703–705.CrossRefGoogle Scholar
Weaver, S. E. 2001. Conyza canadensis: the biology of Canadian weeds. Can. J. Plant Sci. 81:867–875.CrossRefGoogle Scholar
Zelaya, I. A., Owen, M. D. K., and VanGessel, M. J. 2004. Inheritance of evolved resistance in Conyza canadensis L. Cronq. Theor. Appl. Gen. 110:58–70.CrossRefGoogle ScholarPubMed