Martin Laforest

Current research and/or projects

Early detection, monitoring and management of herbicide resistant weeds in field vegetables

Complexe herbicide resistance

Triazine resistant Chenopodium album

Impact of cover crops in horticulture

Research and/or project statements

My projects consist in detecting the presence of herbicide-resistant weeds and explaining the mechanism that the plant uses to survive the herbicide treatment. With this information, we develop genetic tests (molecular markers) which make possible the rapid detection of identical cases. We also study weed populations in order to better understand and possibly act on field implantation. This work is in line with the sector strategy in several ways. By its innovation, it allows to be more competitive in the external markets because it reduces the cost of inputs (herbicides) and therefore the cost of production. These tools, which provide rapid knowledge of resistance cases, mitigate risks and prevent unnecessary use of herbicides while encouraging the development of farming methods that will produce better results using resources with more efficiency. 

Professional activities / interests

Molecular mechanisms of weeds herbicide resistance
Development of diagnostic tools for herbicide resistance

Population genetics of weeds

Genetics, genomics and transcriptomics

Education and awards

Ph.D. Molecular Biology, Laval Université, 1999
B.Sc. Biological Sciecnes, University of Montréal, 1992

Key publications

  1. Dhariwal, G.*, Kennedy, L., Pittman, M., Bessette, M., Laforest, M., and Geddes, C.M. 2023. P197L and W574L amino acid substitutions confer ALS inhibitor resistance in pale smartweed (Persicaria lapathifolia). 2023 Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Oral Presentation).

    2023 - View publication details

  2. Hickmott, H., F. Tardiff, I. Rajcan, S. Meloche, M. Laforest and E.R. Page. Heterosis and the inheritance of paraquat resistance in Canada fleabane. 2021. Annual meeting of the Canadian Weed Science Society, Halifax, N.S., November 14-17.

    2022 - View publication details

  3. Weed emergence and growth under mini-greenhouses in muck and clay soils. Simard, M.-J1., Lord, E1., Nurse, R.E2., Laforest, M1. and Smith, T3. 1Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, QC; 2AAFC, Harrow, ON; 3AAFC, Ottawa.

    2022 - View publication details

  4. Laforest, M. S. Martin, S. Meloche, B. Soufian, K. Bisaillon, F. Tardif and E.R. Page. 2021. Chromosome-Scale Draft Genomes of Common and Giant Ragweed Reveal a Potential Mechanism of Glyphosate Resistance. Annual meeting of the Canadian Weed Science Society, Halifax N.S., November 14-17.

    2022 - View publication details

  5. Laforest, M., Simard, M.-J., Nurse, R., Page, E., Geddes, C.M., Obeid, K., Picard, A., Miville, D., Grainger, C., and Kora, C. 2022. Available genetic testing enables early detection and mitigation of herbicide-resistant weeds. 2022 Joint Meeting of the Canadian Weed Science Society/Canadian Society of Agronomy. Nov 14-18, 2022. Halifax, NS, CA. (Poster Presentation).

    2022 - View publication details

  6. Page, E.R.*, R.E. Nurse, S. Meloche, K. Bosveld, C. Grainger, K. Obeid, M. Filotas, M.J. Simard and M. Laforest. 2021. Import of Palmer amaranth (Amaranthus palmeri S. Wats.) seed with sweet potato (Ipomea batatas
    (L.) Lam) slips. Joint virtual meeting of the Canadian Weed Science Society and Weed Science Society of America, February 22nd – 24th 2022 (Poster Presentation).

    2022 - View publication details

  7. Simard, M-J, Laforest, M., Martin, S. and Maheux, L. 2022. Competition between bird’s rape and canola in unmanaged field borders: Year 1. Weed Science Society of America/Canadian Weed Science Society meeting, February 22-24, Online. Poster

    2022 - View publication details

  8. Laforest, M., Bisaillon, K., Soufiane, B. Maheux, L., Fortin S., Martin, S., James T. , Miville D. , Marcoux, A. and Simard, M.-J. 2021. Glyphosate Resistant Bird Rape Mustard (Brassica rapa) Through Introgression of a Transgenic Construct: Distribution and Genetic Characterization. Weed Science Society of America meeting, March 15-18, Online.

    2021 - View publication details

  9. Pandian, B.A., Friesen, A., Laforest, M., Peterson, D.E., Vara Prasad, P.V., Jugulam, M. (2020). Confirmation and characterization of the first case of acetolactate synthase (ALS)-inhibitor resistant wild buckwheat (Polygonum convolvulus) in the United States. Agronomy, [online] 10(10),

    2020 - View publication details

  10. McKenzie-Gopsill, A., Graham, G., Laforest, M., Ibarra, S., Hann, S., Wagg, C. (2020). Occurrence and management of PSII-inhibitor-resistant chenopodium album L. In atlantic canadian potato production. Agronomy, [online] 10(9),

    2020 - View publication details

  11. McKenzie-Gopsill AG, Graham G, Laforest M, Ibarra S, Hann S, Wagg C. 2020. Tracking and managing triazine resistant Chenopodium album in Atlantic Canadian potato production. Prince Edward Island Soil and Crop Conference. March 5th 2020, Summerside PE Canada

    2020 - View publication details

  12. McKenzie-Gopsill AG, Graham G, Laforest M, Ibarra S, Hann S, Wagg C. 2020. Tracking and managing triazine resistant Chenopodium album in Atlantic Canadian potato production. New Brunswick Soil and Crop Improvement Association Annual General Meeting. Feb 21st 2020, Woodstock NB Canada

    2020 - View publication details

  13. Plant and Animal Genome Conference, January 11-15, 2020.

    2020 - View publication details

  14. Page, E.R., Meloche, S., Bae, J., Larsen, R.J., Laforest, M., Nurse, R.E. (2019). Tricotyledenous giant ragweed (Ambrosia trifida L.). Canadian Journal of Plant Science, [online] 99(1), 84-87.

    2019 - View publication details

  15. Laforest, M., Bisaillon, K., Ciotola, M., Cadieux, M., Hébert, P.O., Toussaint, V., Svircev, A.M. (2019). Rapid identification of erwinia amylovora and pseudomonas syringae species and characterization of E. Amylovora streptomycin resistance using quantitative PCR assays. Canadian Journal of Microbiology, [online] 65(7), 496-509.

    2019 - View publication details

  16. Laforest, M., Soufiane, B. (2018). Coevolution of two sulfonylurea-resistant common chickweed (Stellaria media) biotypes with different mutations in the acetolactate synthase Gene. Weed Science, [online] 66(4), 439-445.

    2018 - View publication details

  17. Page, E.R., Grainger, C.M., Laforest, M., Nurse, R.E., Rajcan, I., Bae, J., Tardif, F.J. (2018). Target and Non-target site Mechanisms Confer Resistance to Glyphosate in Canadian Accessions of Conyza canadensis. Weed Science, [online] 66(2), 234-245.

    2018 - View publication details

  18. Breeden, S.M., Brosnan, J.T., Breeden, G.K., Vargas, J.J., Eichberger, G., Tresch, S., Laforest, M. (2017). Controlling Dinitroaniline-Resistant Goosegrass (Eleusine indica) in Turfgrass, 31(6), 883-889.

    2017 - View publication details

  19. Laforest, M., Soufiane, B., Simard, M.J., Obeid, K., Page, E., Nurse, R.E. (2017). Acetyl-CoA carboxylase overexpression in herbicide-resistant large crabgrass (Digitaria sanguinalis). Pest Management Science, [online] 73(11), 2227-2235.

    2017 - View publication details

  20. Marie-Josée Simard,a Martin Laforest,a Brahim Soufiane,a Diane Lyse Benoit,a François J. Tardifb

    2017 - View publication details

Research facility

430 Gouin Boulevard
Saint-Jean-sur-Richelieu, QC J3B 3E6


Canadian Weed Science Society
Québec Society for the Protection of Plants

Weed Science Society of America

International Weed Science Society

Associate Professor, Laval University