Silver scurf, caused by the fungus Helminthosporium solani, is a common disease of potato and is present in all major production areas in the United States. The incidence and severity of silver scurf in New York, and its associated economic losses, have increased since about 1985. The brown blemishes that develop on the tuber surface lower the market value of the crop. These losses are greatest when the disease occurs on tubers with white or red skin intended for the table-stock market. The increased water loss from infected tubers during storage results in shrinkage that can be economically significant. Silver scurf-infected tubers may be more susceptible to secondary infection by other pathogens. Silver scurf infection has been associated with decreased seed-tuber vigor, but the importance of these effects is not well documented.