In 2017 and 2018 Dr Eugenia Banks, Potato Specialist with the Ontario Potato Board in Canada, conducted common scab research on potatoes that included the identification of the common scab bacteria present in Ontario potato fields. Dr Banks sampled 50 fields and submitted the soil samples to A & L Laboratories. A&L identified the different scab bacterium species using PCR.
The results of the PCR tests indicated that Streptomyces stelliscabiei was the most common bacteria found followed by S. scabiei. The lab also found that the higher the organic matter (OM) in the soil samples, the lower the levels of S. stelliscabiei. (This research was supported by the Ontario Potato Board).
Dr Banks says Streptomyces caviscabies is a common scab bacterium that causes deep, star-shaped lesions (see photo below). Growers have told Dr Banks that this is