John Spafford
Graduate Student
In 2022, Michigan’s cucumber industry was valued at $63.2 million, $45.5 million of which was generated by pickling cucumber production. Cucurbit downy mildew (CDM) represents one of the top disease concerns for Michigan cucumber growers and left untreated can lead to greater than 80% yield loss. CDM is caused by the obligate, oomycete pathogen Pseudoperonospora cubensis; while it is unable to survive Michigan winters, its spores arrive to MI cucumber fields in spring/summer via wind. CDM requires frequent fungicide applications to successfully manage, but P. cubensis readily adapts to the fungicides used to control it. The number of fungicide applications can be optimized by utilizing spore traps and disease forecasters. Spore traps can track the pathogen as it spreads across Michigan and notify growers when to begin applications. Disease forecasters can analyze weather conditions favorable to disease development to inform the frequency of applications. My research will focus on P. cubensis populations and optimizing spore traps, disease forecasters, and new fungicides to better inform cucumber growers of best management practices.
- Spafford, J.R. and Hausbeck, M.K. 2024. Evaluating new fungicides with the TOMCAST forecasting model to limit Stemphylium vesicarium on asparagus fern. Phytopathology (accepted).
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Hausbeck, M.K. and Spafford, J. 2024. Downy Mildew Update. Great Lakes Fruit, Vegetable and Farm Market Expo. Grand Rapids, MI. 10 Dec. Proceedings.
Spafford, J. and Hausbeck, M.K. 2024. Asparagus Pathology Research. Great Lakes Fruit, Vegetable and Farm Market Expo. Grand Rapids, MI. 10 Dec. Proceedings.
- Spafford, J.R., Harlan, B.R., and Hausbeck, M.K. 2024. Evaluation of fungicides for the control of downy mildew of impatiens in the greenhouse, 2023. Plant Disease Management Reports 18:OT026.
- Perla, D.E., Spafford, J.R., and Hausbeck, M.K. 2024. Efficacy of conventional and biorational products to control Phytophthora crown rot using a partially resistant Cucurbita maxima cultivar, 2023. Plant Disease Management Reports 18:V101.
- Tippett, E.S., Spafford, J.R., and Hausbeck, M.K. 2024. Evaluation of fungicides for control of Puccinia malvacearum on common mallow, 2023. Plant Disease Management Reports 18:V066.
- Spafford, J. R, Tippett, E.S., and Hausbeck, M.K. 2024. Evaluating organic fungicides for the control of foliar blights of organic carrot, 2023. Plant Disease Management Reports 18:V078.
- Spafford, J. R., Tippett, E.S., and Hausbeck, M.K. 2024. Evaluating conventional fungicides for the control of Alternaria leaf blight of carrot, 2023. Plant Disease Management Reports 18:V077.
- Spafford, J. R., Perla, D.E., and Hausbeck, M.K. 2024 Combining conventional and biorational fungicides for the control of purple spot disease on asparagus fern, 2023. Plant Disease Management Reports 18:V076.
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Hausbeck, M.K., Spafford, J.R., and Engfehr, C.L. 2023. Purple Spot Disease of Asparagus. Updated Nov 2023. Online.
- Spafford, J., Kenny, G., and Hausbeck, M.K. 2022. Evaluation of new fungicides with TOMCAST forecasting model to limit Stemphylium vesicarium on asparagus fern. 10th International IPM Symposium. Poster.
- Spafford, J.R., and Hausbeck, M.K. 2023. Evaluating fungicides for control of Stemphylium vesicarium on asparagus fern, 2022. Plant Disease Management Reports 17:V065.
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Spafford, J. and Hausbeck, M.K. 2022. Asparagus Pathology Research. Great Lakes Farm, Fruit, and Vegetable Expo. Grand Rapids, MI. 6 Dec. Proceedings.
- Spafford, J.R., Kenny, G., and Hausbeck, M.K. 2022. Evaluating fungicides applied according to the TOMCAST forecasting model for their ability to provide long-lasting control of Stemphylium vesicarium on asparagus fern, 2021. Plant Disease Management Reports 16:V176.
- Spafford, J. and Hausbeck, M.K. 2022. Asparagus Pathology Research. Great Lakes Farm, Fruit, and Vegetable Expo. Proceedings.
- Hausbeck, M.K., Spafford, J.R., and Engfehr, C.L. 2022. Purple Spot Disease of Asparagus. Updated Dec 2022. Online.
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Spafford, J. and Hausbeck, M.K. 2024. Asparagus Pathology Research. Great Lakes Fruit, Vegetable and Farm Market Expo. Grand Rapids, MI. 10 Dec. 68 attendees.
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Spafford, J. and Hausbeck, M. 2024. Using the weather to determine the days between sprays for downy mildew. Annual Meeting of Pickle Packers, Inc., Chicago, IL, 29-31 Oct.
Spafford, J. and Hausbeck, M. 2024. 2024 Spore trapping and fungicide trial results for downy mildew in Michigan. Annual Meeting of Pickle Packers, Inc., Chicago, IL, 29-31 Oct.
- Spafford, J.S. and Hausbeck, M.K. 2024. Evaluating new fungicides with TOMCAST forecasting model to limit Stemphylium vesicarium on asparagus fern. Plant Health, American Phytopathological Society, Memphis, TN, 27-30 Jul. Poster presentation.
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Spafford, J.S. and Hausbeck, M.K. 2024. Asparagus pathology research update. Michigan Asparagus Growers, New Era, MI, 29 Mar.
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Spafford, J.S. and Hausbeck, M.K. 2024. Asparagus pathology research update. Michigan Asparagus Advisory Board, Dewitt, MI, 20 Feb.
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Spafford, J. and Hausbeck, M.K. 2023. Asparagus Pathology Research. Great Lakes Fruit, Vegetable and Farm Market Expo: asparagus. Grand Rapids, MI. 5 Dec. 60 attendees.
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Spafford, J. and Hausbeck, M.K. 2022. Asparagus pathology Research. Great Lakes Farm, Fruit, and Vegetable Expo. Grand Rapids, MI. 6 Dec. 85 attendees.
