Tuber Talk
Podcast: Takeaways of PED research in Alberta with Colby Robertson

For the past two years, Colby Robertson investigated the impact of soil treatments on southern Alberta fields with high pathogen levels for Verticillium and root-lesion nematode. These two pathogens are involved in potato early dying complex (PED) – a disease that can shave 15 to 30 per cent off a field’s yield potential.

Robertson briefly explains the research and shares takeaways for potato growers. In addition, Robertson shares what he’s learned as a potato researcher and how he began working with potatoes from his hometown of Carberry, Man. to where he is today in Alberta.

Editor’s note: Throughout the podcast, Colby does not use the market names of products but refers to them by active ingredients. Feel free to reach out to Colby directly or click on the research paper below for more information.

You can find Colby Robertson on Twitter and send him potato jokes at @TuberAwesome.

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The music used in this episode is Vital Signs from Purple Planet Music.

Show notes

• Full paper in American Journal of Potato Research: Impact of Fumigation on Soil Microbial Communities under Potato Cultivation in Southern Alberta 
• Robertson’s key takeaway: Soil sample for more than your macros and micros; include biological measurements beyond soil organic matter. Lab methods are being developed to help make PED pathogen quantification quicker, cheaper, and more reliable, but they need participants to make it work. (CanPEDNet is a Canada-wide project working on this in collaboration with growers across Canada).
• Robertson has written a more in-depth summary of his research:

“In collaboration with southern Alberta potato growers, McCain Foods, Cavendish Farms, Lamb Weston, and the University of Lethbridge, there have been potato fields identified as potential candidates for managing a disease of potato in Southern Alberta. This is called Potato Early Dying complex (PED) and involves two pathogens. They are a soil-borne fungus (Verticillium) and a soil-borne nematode (root-lesion nematode, small worm, not segmented like your typical earthworm, requires microscope to be identified).

I soil sampled the selected fields at various times. That soil was sent to various laboratories to check the levels of the pathogens in the soil. Specific soil treatments were applied to determine how well they reduced pathogen levels in the soil. Yield of the potato crop and quality of the tubers were also judged in response to soil treatment. The soil treatments included a fumigant, an in-furrow fungicide, and an in-furrow nematicide.

Beyond pathogen levels in the soil, crop yield, and how they both responded to each soil treatment, I also had a microbial community structural analysis completed on the soil samples. Information garnered from this included total bacteria in the soil, total fungi, the ratio of the two, and what proportion of specific taxonomic groups comprised the communities (i.e. several different Orders were assessed for their proportions relative to each other; 10% of Order 1, 30% of Order 2, 22% of Order 3, etc.).”