Potato Facts By Steven B. Johnson, Ph.D., 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/. Bulletin #5041, Verticillium Wilt of Potatoes (PDF) History Verticillium wilt symptoms with poor rotation (on left). Compare to good rotation on right.