Efficacy of 2,4-D Choline/Glyphosate Dimethylamine on Glyphosate Resistant Canada Fleabane (Conyza canadensis) at Different Sizes


Glyphosate resistant (GR) Canada fleabane has spread quickly across southwestern Ontario and new strategies for the control of this competitive weed must be developed especially in no-tillage crops. A premix of 2,4-D choline and glyphosate dimethylamine (DMA) has been developed for application on tolerant corn, soybean and cotton crops that provides an option for the control of this problematic GR weed. The objective of this research was to determine the required dose needed to effectively control GR Canada fleabane at different size categories in field and greenhouse experiments. In the field experiments, nine rates of 2,4-D choline/glyphosate DMA (53.8 to 13,760 g·ae·ha-1) were applied to GR Canada fleabane that were 10 cm in diameter/tall, 20 cm tall or 30 cm tall. Similarly, in the greenhouse, seven rates of 2,4-D choline/glyphosate DMA (0 to 3440 g·ae·ha-1) were applied to 10, 20 and 30 cm tall GR Canada fleabane plants. The three different size classes of GR Canada fleabane responded similarly to 2,4-D choline/glyphosate DMA in the field experiment. In the greenhouse there were some differences in control for the three size classes of GR Canada fleabane with 2,4-D choline/glyphosate DMA; the 20 and 30 cm tall plants required similar rates to provide equivalent control, but the 10 cm plants required a lower rate. In all situations, greater than 1720 g·ae·ha-1 of 2,4-D choline/glyphosate DMA was required to provide 95% control of 10, 20 and 30 cm tall Canada fleabane in greenhouse (35 DAA) and field experiments (8 WAA), respectively.

Share and Cite:

Ford, L. , Soltani, N. , Robinson, D. , Nurse, R. , McFadden, A. and Sikkema, P. (2014) Efficacy of 2,4-D Choline/Glyphosate Dimethylamine on Glyphosate Resistant Canada Fleabane (Conyza canadensis) at Different Sizes. American Journal of Plant Sciences, 5, 2755-2763. doi: 10.4236/ajps.2014.518292.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Byker, H.P., Soltani, N., Robinson, D., Tardif, F., Lawton, M. and Sikkema, P.H. (2013) Occurrence of Glyphosate and Cloransulam Resistant Canada Fleabane (Conyza canadensis L. Cronq.) in Ontario. Canadian Journal of Plant Science, 93, 851-855.
[2] Kruger, G.R., Davis, V.M., Weller, S.C. and Johnson, W.G. (2010) Growth and Seed Production of Horseweed (Conyza canadensis) Populations after Exposure to Postemergence 2,4-D. Weed Science, 58, 413-419.
[3] Dauer, J.T., Mortensen, D.A. and Humston, R. (2006) Controlled Experiments to Predict Horseweed (Conyza canadensis) to Dispersal Distances. Weed Science, 54, 484-489.
[4] Shields, E.J., Dauer, J.T., VanGessel, M.J. and Neumann, G. (2006) Horseweed (Conyza canadensis) Seed Collected in the Planetary Boundary Layer. Weed Science, 54, 1063-1067.
[5] Weaver, S.E. (2001) The Biology of Canadian Weeds. 115. Conyza Canadensis. Canadian Journal of Plant Science, 81, 867-875. http://dx.doi.org/10.4141/P00-196
[6] Cici, S.Z.H. and VanAcker, R.C. (2009) A Review of the Recruitment Biology of Winter Annual Weed in Canada. Canadian Journal of Plant Science, 89, 575-589.
[7] Coupland, D. (1994) Resistance to the Auxin Analog Herbicides. In: Holtum, J.A.M. and Powlesm, S.B., Eds., Herbicide Resistance in Plants: Biology and Biochemistry, Lewis Publishers, Boca Raton, 171-214.
[8] Heap, I. (2014) The International Survey of Herbicide Resistant Weeds. www.weedscience.com
[9] Anonymous (2012) Technical Bulletin: A System Approach to Broad-Spectrum Weed Management for Corn, Soybeans and Cotton. Dow AgroSciences Publication, Indianapolis.
[10] Bolan, N.S. and Baskaran, S. (1996) Biodegradation of 2,4-D Herbicide as Affected by Its Adsorption-Desorption Behavior and Microbial Activity of Soils. Australian Journal of Soil Research, 34, 1041-1053.
[11] Bayley, C., Trolinder, N., Ray, C., Morgan, M., Quisenberry, J.E. and Ow, D.W. (1992) Engineering 2,4-D Resistance into Cotton. Theoretical and Applied Genetics, 83, 645-649.
[12] Storrie, A. (2014) Reducing Herbicide Spray Drift. NSW Agriculture. www.agric.nsw.gov.au
[13] Green, J.M. and Owen, M.D.K. (2010) Herbicide-Resistant Crops: Utilities and Limitations for Herbicide-Resistant Weed Management. Journal of Agricultural and Food Chemistry, 59, 5819-5829.
[14] Hillger, D.E., Qin, K., Simpsonand, D.M. and Havens, P. (2012) Reduction in Drift and Volatility of EnlistTM Duo with Colex-D. Proceedings of the 65th Annual Meeting of the North Central Weed Science Society Conference Proceedings, 65, 38.
[15] Kruger, G.R., Davis, V.M., Weller, S.C. and Johnson, W.G. (2008) Response and Survival of Rosette-Stage HORSEWEED (Conyza canadensis) after Exposure to 2,4-D. Weed Science, 56, 748-752.
[16] Kruger, G.R., Davis, V.M., Weller, S.C. and Johnson, W.G. (2010) Control of Horseweed (Conyza canadensis) with Growth Regulator Herbicides. Weed Technology, 24, 25-429.
[17] Keeling, W.J., Henniger, G.C. and Abernathy, J.R. (1989) Horseweed (Conyza canadensis) Control in Conservation Tillage Cotton (Gossypium hirsutum). Weed Technology, 3, 399-401.
[18] Bowley, S. (2008) A Hitchhiker’s Guide to Statistics in Plant Biology. 2nd Edition, Any Old Subject Books, Guelph, 266 p.

Copyright © 2022 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.