Submitted to: Potato Progress
Publication Type: Trade Journal
Publication Acceptance Date: November 22, 2010
Publication Date: December 14, 2010
Citation: Wanner, L.A. 2010. The search for integrated management of common scab. Potato Progress. X:13.
Common scab (CS), caused by several species of Streptomyces, is a soil-borne bacterial disease of potato and other root and tuber crops. Frustratingly, CS severity is highly variable (and unpredictable) from year to year and location to location. Symptoms include superficial, raised, or pitted lesions which may be discrete, or may coalesce to cover large areas of the underground tuber. Although CS was first described in the literature more than 100 years ago, it continues to be a significant problem in potato production world-wide. Most popular potato cultivars are quite susceptible to the disease. Growers report serious CS in new areas, and on cultivars that were thought to be resistant. Traditional control measures are insufficient and often fail, including reducing soil pH and keeping plants well-irrigated from the time of tuber initiation through early development. Planting cultivars with the best CS resistance in your region is currently the most successful control strategy. Research is focused on two areas that may help in controlling CS: (1) developing rational, research-based CS control methods based on understanding the pathogen, its distribution, and why it causes disease (when it does); and (2) development of CS-resistant (tolerant) potato cultivars.