Dr. Charles M. Geddes, Ph.D., P.Ag.

Research Scientist - Weed Ecology and Cropping Systems

Herbicide-resistant plants
Weed ecology, biology and management
Integrated weed management
Weed seedbank dynamics
Crop/weed interference
Long-term agroecosystem experiments

Lethbridge Research and Development Centre

Current research and/or projects

16. Principal Investigator. Title "Old plots, new hypotheses: Toward a revitalized AAFC long-term agroecosystem experiment (LTAE) network." AAFC Management Solicited Initiative. 2019-2022.

15. Principal Investigator. Title "Development of an integrated weed management (IWM) package to mitigate and manage glyphosate-resistant weeds in soybean." WGRF, MPSG, CAP Ag Action MB Program. 2019-2024.

14. Principal Investigator. Title "Management of glyphosate-resistant kochia in western Canadian cropping systems." ICA Cluster - CAP, WGRF, MPSG, MWBGA, AAFC. 2018-2023.

13. Principal Investigator. Title "Weed seed-suppressive soils: Managing herbicide-resistant weed populations at the source." AAFC A-base. 2018-2021.

12. Co-Investigator. Title "Beneficial insects in Prairie crops: quantifying the value and vulnerability of biological pest control." AAF, AWC, AB, SWDC. 2019-2022.

11. Co-Investigator. Title "Development of improved protocols for the culture of arbuscular mycorrhizal fungi with high symbiotic potential according to the analyses of soil microbiome." AAFC A-base. 2018-2021.

10. Co-Investigator. Title "Delivery of an innovative winter wheat package to achieve sustainable wheat production in the Canadian Prairies." CNW Cluster - CAP. 2018-2023.

9. Co-Investigator. Title "Glyphosate-resistant kochia/Russian thistle surveys." WGRF. 2018-2023.

8. Co-Investigator. Title "Identifying agronomic and environmental benefits and drawbacks of diverse crops in cereal/canola/pulse crop rotations on the semi-arid Canadian Prairies. DFC Cluster - CAP. 2018-2023.

7. Co-Investigator. Title "Improving the management of sclerotinia stem rot of canola using fungicides and better risk assessment tools. CAR Cluster - CAP. 2018-2023.

6. Co-Investigator. Increasing the suitability of the Holos model for life cycle analysis through production cycle inputs, collaborative/open source development, and the development of representative farm systems. AAFC A-base. 2019-2022.

5. Co-Investigator. Integrating multiple beneficial management practices (BMPs) in an organic cropping system: Soil health, weed and insect interactions. AAFC A-base. 2018-2021.

4. Co-Investigator. Title "Long-term sustainable canola production - All phases rotations. WGRF, ACPC. 2017-2020.

3. Co-Investigator. Title "Manipulating agronomic factors for optimum canola harvest timing, productivity and crop sequencing." CAR Cluster - CAP. 2018-2023.

2. Co-Investigator. Title "Mitigating herbicide resistance - Investigating novel integrated weed maangement systems." WGRF, ACPC, ABC, SWDC. 2016-2021.

1. Co-Investigator. Title "The right balance: Management strategies for plugging organic soil health constraints and moving forward." OS Cluster III - CAP. 2018-2023.

Education and awards

Doctor of Philosophy (Plant Science), University of Manitoba, 2018

Bachelor of Science (Agroecology), University of Manitoba, 2012

Key publications

Geddes, C.M.* 2023. Kochia combat: Winning the war with knowledge, innovation and strategy. WinField Agronomy Academy Conference. Saskatoon, SK. Nov 28, 2023. (Oral Presentation). Invited.
2023 - View publication details
Geddes, C.M.*, Pittman, M., Brown-Livingston, K., and Leeson, J. 2023. Manitoba survey of herbicide-resistant weeds in 2022. 2023 Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Poster Presentation).
2023 - View publication details
Geddes, C.M.*, Dhariwal, G., Kennedy, L., and Pittman, M. 2023. Ile2041Asn substitution confers ACCase inhibitor resistance in foxtail barley (Hordeum jubatum). 2023 Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Poster Presentation).
2023 - View publication details
Geddes, C.M.*, Jayasekara, S., Anderson, M., Gulden, R., and Holzapfel, C. 2023. Weed suppression by integrating cultural tactics in western Canadian soybean production. 2023 Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Poster Presentation).
2023 - View publication details
Geddes, C.M.* 2023. Introduction to the 2023 Kochia Summit: Kochia research and priorities. 2023 Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Oral Presentation).
2023 - View publication details
Zvomuya, J.*, Geddes, C.M., and Gulden, R.H. 2023. Root elongation among 10 soybean genotypes at different temperatures. Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Oral Presentation).
2023 - View publication details
Geddes, C.M.*, Jaster, A., and Pittman, M. 2023. Protoporphyrinogen oxidase inhibitor (Group 14)-resistant kochia (Bassia scoparia). 2023 Annual Meeting of the Canadian Weed Science Society. Nov 20-23, 2023. Winnipeg, MB, CA. (Oral Presentation).
2023 - View publication details
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
Tidemann BD, Geddes CM, Sharpe SM (2023) Investigating the 2014-2017 Prairie Herbicide Resistance Samples for False Cleavers (Galium spurium) Response to Quinclorac. Canadian Weed Science Society Annual Meeting, Winnipeg, MB. 2023/11/20 - 2023/11/23
2023 - View publication details
Geddes, C.M.* 2023. Weed Management. Alberta Grains – Region 1 Meeting. Lethbridge, AB. Nov 15, 2023. (Oral Presentation). Invited.
2023 - View publication details
Geddes, C.M.*, and Cranston, R. 2023. 2023 Western Canadian herbicide resistance update. TopCrop Webinar. Virtual. Nov 09, 2023. (Oral Presentation). Invited.
2023 - View publication details
Geddes, C.M.* 2023. Keynote #2: Herbicide-resistant kochia management. 2023 Nufarm Kochia Summit. Deadwood, SD, USA. Oct, 26, 2023. (Oral Presentation). Invited.
2023 - View publication details
Geddes, C.M.* 2023. Keynote #1: Herbicide-resistant kochia on the Canadian Prairies. 2023 Nufarm Kochia Summit. Deadwood, SD, USA. Oct, 25, 2023. (Oral Presentation). Invited.
2023 - View publication details
Geddes, C.M.* 2023. Weed biovigilance kits/genetic analyses. 2023 Annual Meeting of the Prairie Biovigilance Network. Agriculture and Agri-Food Canada. Saskatoon, SK. Sep 19, 2023. (Oral Presentation).
2023 - View publication details
Prabahar Ravichandran, Keshav D. Singh, Charles M. Geddes, Breanne Tidemann, Eric Johnson, Steve Shirtliffe, Thomas K. Turkington, and Manoj Natarajan, "Utilizing Hyperspectral Imaging Technology to Characterize Herbicide Phytotoxicity in Oat and Mustard", 11th International Conference of Agro-Geoinformatics, Wuhan, China, July 2023
2023 - View publication details
Prabahar Ravichandran, Keshav D. Singh, Charles M. Geddes, Manoj Natarajan, Austin Jaster, and Hongquan Wang, "Proximal Hyperspectral Imaging to Classify Herbicide-Resistant and -Susceptible Kochia (Bassia Scoparia)", 11th International Conference of Agro-Geoinformatics, Wuhan, China, July 2023
2023 - View publication details
Geddes, C.M. 2023. Weed management and resistance. WheatStalk 2023. AlbertaGrains. Vermillion, AB. Jul 25, 2023. (Oral Presentation). Invited.
2023 - View publication details
Geddes, C.M. 2023. T.K.O. for herbicide resistance, population x row spacing x herbicide. Farming Smarter 2023 Plot Hop. Lethbridge, AB. Jul 13, 2023. (Oral Presentation). Invited.
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Geddes, C.M. 2023. Alberta Canola Producers Commission field tour. Lethbridge Research and Development Centre. Lethbridge, AB. Jul 11, 2023. (Oral Presentation).
2023 - View publication details
Geddes, C.M. 2023. Herbicide-resistant weeds and their management on the prairies. AAFC Pest Management Centre – IWM strategy and sustainable weed management webinar. Mar 14, 2023. Invited.
2023 - View publication details