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Herbicide Timing and Rate Effects on Weed Management in Three Herbicide-Resistant Canola Systems

Published online by Cambridge University Press:  20 January 2017

K. Neil Harker*
Affiliation:
Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada
George W. Clayton
Affiliation:
Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada
John T. O'Donovan
Affiliation:
Agriculture and Agri-Food Canada, Beaverlodge Experimental Farm, Box 26, Beaverlodge, AB T0H 0C0, Canada
Robert E. Blackshaw
Affiliation:
Agriculture and Agri-Food Canada, Lethbridge Research Centre, Box 3000, Lethbridge, AB T1J 4B1, Canada
F. Craig Stevenson
Affiliation:
142 Rogers Road, Saskatoon, SK S7N 3T6, Canada
*
Corresponding author's E-mail: [email protected]

Abstract

Herbicide-resistant canola dominates the canola market in Canada. A multiyear field experiment was conducted at three locations to investigate the effect of time of weed removal (two-, four-, or six-leaf canola) and herbicide rate (50 or 100% recommended) in three herbicide-resistant canola systems. Weeds were controlled in glufosinate-resistant canola (GLU) with glufosinate, in glyphosate-resistant canola (GLY) with glyphosate, and in imidazolinone-resistant canola (IMI) with a 50:50 mixture of imazamox and imazethapyr. Canola yields were similar among the three canola cultivar–herbicide systems. Yields were not influenced by 50 vs. 100% herbicide rates. Timing of weed removal had the greatest effect on canola yield, with weed removal at the four-leaf stage giving the highest yields in most cases. Percent dockage was often greater for GLU and IMI than for GLY. In comparison with the other treatments, dockage levels doubled for GLU after application at 50% herbicide rates. The consistency of monocot weed control was usually greater for GLY than for GLU or IMI systems. However, weed biomass data revealed no differences in dicot weed control consistency between IMI and GLY systems. Greater dockage and weed biomass variability after weed removal at the six-leaf stage or after low herbicide rates suggests higher weed seed production, which could constrain the adoption of integrated weed management practices in subsequent years.

Type
Research
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Barton, D. L., Thill, D. C., and Shafii, B. 1992. Integrated wild oat (Avena fatua) management affects spring barley (Hordeum vulgare) yield and economics. Weed Technol. 6:129135.Google Scholar
Blackshaw, R. E., Semach, G. P., and O'Donovan, J. T. 2000. Utilization of wheat seed rate to manage redstem filaree (Erodium cicutarium) in a zero-tillage cropping system. Weed Technol. 14:389396.Google Scholar
Canola Council of Canada. 2001. An agronomic and economic assessment of transgenic canola. Report prepared by Serecon Mgmt. Consulting and Koch Paul Assoc. Web page: http://www.canola-council.org/production/ gmo_main.html. Accessed: September 1, 2004.Google Scholar
Cardina, J., Webster, T. M., Herms, C. P., and Regnier, E. E. 1999. Development of weed IPM: levels of integration for weed management. in Buhler, D. D., ed. Expanding the Context of Weed Management. New York: Haworth. Pp. 239267.Google Scholar
Clayton, G. W., Harker, K. N., O'Donovan, J. T., Baig, M. N., and Kidnie, M. J. 2002. Glyphosate timing and tillage system effects on glyphosate-tolerant canola (Brassica napus). Weed Technol. 16:124130.Google Scholar
Hall, L., Topinka, K., Huffman, J., Davis, L., and Good, A. 2000. Pollen flow between herbicide-resistant Brassica napus is the cause of multiple-resistant B. napus volunteers. Weed Sci. 48:688694.CrossRefGoogle Scholar
Harker, K. N., Blackshaw, R. E., Kirkland, K. J., Derksen, D. A., and Wall, D. 2000. Herbicide-tolerant canola: weed control and yield comparisons in Western Canada. Can. J. Plant Sci 80:647654.CrossRefGoogle Scholar
Harker, K. N., Clayton, G. W., Blackshaw, R. E., O'Donovan, J. T., and Stevenson, F. C. 2003. Seeding rate, herbicide timing and competitive hybrids contribute to integrated weed management in canola (Brassica napus). Can. J. Plant Sci 83:433440.Google Scholar
Harker, K. N., Clayton, G. W., Turkington, T. K., O'Donovan, J. T., Blackshaw, R. E., and Thomas, P. 2001. How to implement IWM in canola. in Blackshaw, R. E. and Hall, L. M., eds. Integrated Weed Management: Explore the Potential. Quebec: Sainte-Anne-de-Bellevue. Pp. 9198.Google Scholar
Kirkland, K. J., Holm, F. A., and Stevenson, F. C. 2000. Appropriate crop seeding rate when herbicide rate is reduced. Weed Technol. 14:692698.Google Scholar
Liebman, M. and Davis, A. S. 2000. Integration of soil, crop and weed management in low-external-input farming systems. Weed Res 40:2747.Google Scholar
Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. 1996. SAS System for Mixed Models. Cary, NC: SAS Institute. 656 p.Google Scholar
Martin, S. G., Friesen, L. F., and Van Acker, R. C. 2001. Critical period of weed control in spring canola. Weed Sci. 49:326333.Google Scholar
McGill, R., Tukey, J. W., and Larsen, W. A. 1978. Variations of box plots. Am. Stat 32:1216.Google Scholar
O'Donovan, J. T., Harker, K. N., Clayton, G. W., Robinson, D., Newman, J. C., and Hall, L. M. 2001. Barley seeding rate influences the effects of variable herbicide rates on wild oat (Avena fatua). Weed Sci. 49:746754.Google Scholar
O'Donovan, J. T. and Newman, J. C. 1996. Manipulation of canola (Brassica rapa) plant density and herbicide rate for economical and sustainable weed management. in Proceeding of the 2nd International Weed Control Congress; June 25–28, 1996; Copenhagen, Denmark. Slagelse, Denmark: Department of Weed Control and Pesticide Ecology. Pp. 969974.Google Scholar
Spandl, E., Durgan, B. R., and Miller, D. W. 1997. Wild oat (Avena fatua) control in spring wheat (Triticum aestivum) and barley (Hordeum vulgare) with reduced rates of postemergence herbicides. Weed Technol. 11:591597.Google Scholar
Stougaard, R. N., Maxwell, B. D., and Harris, J. D. 1997. Influence of application timing and the efficacy of reduced rate postemergence herbicides for wild oat (Avena fatua) control in spring barley (Hordeum vulgare). Weed Technol. 11:283289.Google Scholar
Tukey, J. W. 1977. Exploratory Data Analysis. 1st ed. Reading, MA: Addison-Wesley. 688 p.Google Scholar
Van Deynze, A. E., McVetty, P. B. E., Scarth, R., and Rimmer, S. R. 1992. Effect of varying seeding rates on hybrid and conventional summer rape performance in Manitoba. Can. J. Plant Sci 72:635641.Google Scholar
Zand, E. and Beckie, H. J. 2002. Competitive ability of hybrid and open-pollinated canola (Brassica napus) with wild oat (Avena fatua). Can. J. Plant Sci 82:473480.Google Scholar