Powdery Scab of Potato

Powdery scab is a formidable and damaging fungus-like pathogen that damages potatoes worldwide. It causes gall formation on roots as well as lesions on the tubers, which reduce potato quality as well as inhibit plant growth and yield. Even worse, once established in a field the pathogen is hard to get rid of — a field can remain infectious for over ten years, even in the absence of a potato crop. Because there are very few effective ways to manage the disease, it’s crucial to know how to minimize the risk of an outbreak. This five-page bulletin discusses the signs and symptoms, the pathogen’s disease cycle and the management options available. Full-color photography helps growers to identify potentially afflicted plants; a handy table identifies which cultivars planted in Idaho are the least susceptible to the disease.