Towards biological control of Spongospora subterranea f. sp subterranea, the causal agent of powdery scab in potato

Powdery scab of potato, caused by the obligate biotrophic protozoan pathogen Spongospora subterranea f.sp. subterranea (Sss), is a major problem in potato growing areas throughout the world. It results in lesions (scabs) on the surface of the tubers which renders them unmarketable. In recent years there has been an increasing number of reports of the disease, many from new areas. Management of the disease has proved difficult and relies on the integrated application of a range of methods. Biocontrol is not currently used for the management of powdery scab although the results of preliminary studies have been encouraging. This review evaluates the potential for developing a biocontrol strategy for powdery scab.