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Critical period of weed control in spring canola

Published online by Cambridge University Press:  20 January 2017

Steven G. Martin ,
Rene C. Van Acker  and
Lyle F. Friesen
Steven G. Martin
Affiliation:
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
Lyle F. Friesen
Affiliation:
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
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Abstract

The critical period of weed control is the portion of the life cycle of a crop during which it must be kept weed-free to prevent yield loss due to weed interference. The advent of herbicide-resistant canola (Brassica napus L.) varieties in western Canada has meant that there are now more options for postemergence weed control in canola, and this has prompted increased interest in identifying the optimum timing for weed control in this crop. A critical period experiment was conducted at three locations in southern Manitoba in 1998 and 1999, and it consisted of two sets of treatments. In the first set of treatments, the crop was kept weed-free for increasing lengths of time to determine when emerging weeds would no longer reduce crop yield. In the second set of treatments, weeds were permitted to grow in the crop for increasing lengths of time to determine when weeds emerging with the crop began irrevocably to reduce crop yield. Results of the experiments indicated that canola must be kept weed-free in most cases until the four-leaf stage of the crop (17–38 days after crop emergence [DAE]) and, in one early-seeded experiment, until the six-leaf stage of the crop (41 DAE), in order to prevent >10% yield loss. After the four- to six-leaf stage of the canola crop, few weeds emerged, and late-emerging weeds accumulated little shoot biomass. Weeds needed to be removed by the four-leaf stage of the crop (17–38 DAE) to prevent >10% yield loss due to weed interference. In all but the early-seeded experiment, the critical weed-free period and the critical time of weed removal overlapped, such that a single weed removal at the four-leaf stage of the crop would have been sufficient to prevent >10% yield loss. This information will be useful for providing weed control recommendations to canola producers.

Keywords

Diquatglufosinateglyphosateterbufosbarnyardgrass, Echinochloa crus-galli (L.) Beauv. ECHCGcanola, Brassica napus L. BRSNS, ‘Innovator’common hempnettle, Galeopsis tetrahit L. GAETEcommon lambsquaters, Chenopodium album L. CHEALcommon purslane, Portulaca oleraceae L. POROLdandelion, Taraxacum officinale Weber in Wiggers TAROFfield pennycress, Thlaspi arvense L. THLARgreen foxtail, Setaria viridis (L.) Beauv. SETVIquackgrass, Elytrigia repens (L.) Nevski AGRREredroot pigweed, Amaranthus retroflexus L. AMAREroundleaved mallow, Malva pusilla Sm. MALPUsmartweed, Polygonum persecaria L. POLPEvolunteer barley, Hordeum vulgare L. HORVXvolunteer flax, Linum usitatissimum L. LINUSvolunteer wheat, Triticum aestivum L. TRZASwild buckwheat, Polygonum convolvulus L. POLCOwild mustard, Brassica kaber (DC.) L. C. Wheeler SINARwild oat, Avena fatua L. AVEFAyellow foxtail, Setaria pumila (Poir.) Roem & Schult. SETLUWeed interferencecompetitiontime of removalcritical period

Information

Type
Research Article
Information
Weed Science , Volume 49 , Issue 3 , June 2001 , pp. 326 - 333
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Baldwin, F. L. and Santelmann, P. W. 1980. Weed science in integrated weed management. Bioscience 30:675–678.Google Scholar
Canadian Grain Commission. 1991. Official Grain Grading Guide. Winnipeg: Government of Canada. 451 p.Google Scholar
Canola Council of Canada. 1998. Brandon, Manitoba: Canola Production Centre: 1998 Rep. pp. 88–95.Google Scholar
Dawson, J. H. 1986. The concept of period thresholds. Pages 327–331 In Proceedings of the European Weed Research Society Symposium, Economic Weed Control. Stuttgart: EWRS.Google Scholar
Hall, M. R., Swanton, C. J., and Anderson, G. W. 1992. The critical period of weed control in grain corn (Zea mays). Weed Sci. 40:441–447.Google Scholar
Harper, F. R. and Berkenkamp, B. 1975. Revised growth-stage key for Brassica campestris and B. napus . Can. J. Plant Sci. 55:657–658.CrossRefGoogle Scholar
Kvalseth, T. O. 1985. Cautionary note about R2 . Am. Stat. 39:279–285.Google Scholar
Manitoba Agriculture. 1999. Summary of Canola Varieties Planted in Manitoba 1996–99.Google Scholar
Martin, S. G. 2000. The Critical Period of Weed Control in Canola (Brassica napus L.). . University of Manitoba, Winnipeg, MB. 119 p.Google Scholar
McGregor, D. I. 1987. Effect of plant density on development and yield of rapeseed and its significance to recovery from hail injury. Can. J. Plant Sci. 67:43–51.Google Scholar
McMullan, P. M., Daun, J. K., and DeClercq, D. R. 1994. Effect of wild mustard (Brassica kaber) competition on yield and quality of triazine-tolerant and triazine-susceptible canola (Brassica napus and Brassica rapa). Can. J. Plant Sci. 74:369–374.Google Scholar
Morrison, M. J., McVetty, P.B.E., and Scarth, R. 1990. Effect of row spacing and seeding rates on summer rape in southern Manitoba. Can. J. Plant Sci. 70:127–137.Google Scholar
Morrison, M. J., McVetty, P.B.E., and Shaykewich, C. F. 1989. The determination and verification of a baseline temperature for the growth of Westar summer rape. Can. J. Plant Sci. 69:455–464.Google Scholar
Nieto, J. H., Brando, M. A., and Gonzalez, J. T. 1968. Critical periods of the crop growth cycle for competition from weeds. PANS 14:159–166.Google Scholar
O’Donovan, J. T. 1992. Seed yields of canola and volunteer barley as influenced by their relative times of emergence. Can. J. Plant Sci. 72:263–267.Google Scholar
Ratkowsky, D. A. 1990. Handbook of Nonlinear Regression Models. New York: Marcel Dekker. pp. 123–147.Google Scholar
Roberts, H. A. 1976. Weed competition in vegetable crops. Ann. Appl. Biol. 83:321–347.Google Scholar
Ross, M. A. and Harper, J. L. 1972. Occupation of biological space during seedling establishment. J. Ecol. 60:77–88.Google Scholar
[SAS] Statistical Analysis Systems. 1990. SAS Procedures Guide. Version 6, 3rd ed. Cary, NC: Statistical Analysis Systems Institute.Google Scholar
Stoller, E. W. and Wax, L. M. 1973. Periodicity of germination and emergence of some annual weeds. Weed Sci. 21:574–580.CrossRefGoogle Scholar
Swanton, C. J. and Weise, S. F. 1991. Integrated weed management: the rationale and approach. Weed Technol. 5:657–663.CrossRefGoogle Scholar
Van Acker, R. C., Weise, S. F., and Swanton, C. J. 1993. The critical period of weed control in soybeans (Glycine max (L.) Merr.). Weed Sci. 41:194–200.CrossRefGoogle Scholar
Wall, D. 1994. Weed Research Report. Morden, Manitoba: Agriculture and Agri-food Canada. p. 2.Google Scholar
Weaver, S. E., Kropff, M. J., and Groeneveld, R.M.W. 1992. Use of ecophysiological models for crop-weed interference: the critical period of weed interference. Weed Sci. 40:302–307.CrossRefGoogle Scholar
Weaver, S. E. and Tan, C. S. 1987. Critical period of weed interference in transplanted tomatoes and its relation to water stress and shading. Can. J. Plant Sci. 67:575–583.Google Scholar