Bulletin #2444, Silver Scurf of Potato (PDF) By Steven B. Johnson, Extension Crops Specialist, University of Maine Cooperative Extension For information about UMaine Extension programs and resources, visit extension.umaine.edu.Find more of our publications and books at extension.umaine.edu/publications/. Tuber with silver scurf. Note the silvery appearance. Helminthosporium solani, a fungus, causes silver scurf disease of potatoes.