Emergence of silver scurf (Helminthosporium solani) as an economically important disease of potato

During the 1990s, silver scurf (causal agent Helminthosporium solani ) emerged as an economically important disease of table stock and processing potatoes ( Solanum tuberosum ). The pathogen attacks the periderm of the potato tuber causing blemishes. The disease cycle of silver scurf has both field and storage phases. Primary infection occurs in the field and high relative humidity favours the spread and increase of silver scurf in potato stores. Control of the disease by chemical and cultural practices remains difficult. Increase in disease has been attributed to H. solani isolates resistant to the postharvest fungicide thiabendazole (TBZ). Polymerase chain reaction (PCR)-based detection methods for H. solani and TBZ-resistant isolates are rapid and more specific than traditional identification. This review discusses the biology of the pathogen, epidemiology of the disease, detection of the pathogen and integrated control measures for the management of silver scurf in both field and potato tuber stores.