Common Scab Potato Disease

Common scab, caused by Streptomyces scabies, is a skin-blemishing potato disease which although has no effect on cooking quality, can greatly affects a crop’s market value.

A tell tale signs of common scab is the appearance of patches of rough, cork-like areas on the tuber’s surface, sometimes known as russetting.  Symptoms of common scab usually become first noticable late in the growing season, or during harvest.


Common Causes and Conditions of Common Scab

Common scab is caused by very common soil organism attacking the tubers at an early stage of development, especially in dry conditions.  Lime can increase the severity of an attack of common scab.

Common scab is not spread during storage.


Affected / Vulnerable Varieties

One potato variety which tends to be more susceptible to common scab is Maris Piper.


Control of Common Scab

Cultural and Methods:
Common scab can be prevented by irrigation at the early stage of formation, making use of irrigation forcast systems and soil measuring equipment optimises water use and disease control.

Chemicals and Pesticides:
Currently there are no chemicals approved in the UK that give adequate control and protection against common scab.