Subjects: Sociology Alerts Jobs Make a Gift Maps / Directions Text Only Accessibility The University of North Carolina at Charlotte 9201 University City Blvd, Charlotte, NC 28223-0001 | 704-687-8622 Â© UNC Charlotte | All Rights Reserved | Terms of Use | Policy Statements
Cause of Potato Scab. The cause of common potato scab is a bacterium, Streptomyces Scabies, found in the soil. It is most common on light, sandy soils, low in organic matter. Soils that were previously grassland are particularly liable to having the disease. Soils with a high pH (recently limed) provide a better environment for the bacteria.
J.A.Turton. 1  Sheep-scab is a condition in sheep caused by infestation with a particular type of mite (Psoroptes ovis, known as the sheep-scab mite). You may see wool in the mouth of the sheep and wool may also be found on fences and other objects against which the sheep rub. 2  Fluid leaks from the irritated skin, and dries to form yellow crusts or scabs. 3  This is why the condition is called scab. 4  You will see bare, scabby patches and matted wool.