Pest Management Fact Sheet #5091 Authors: Dr. Alicyn Smart, Dr. Bruce Watt, and Abigayl Novak For information about UMaine Extension programs and resources, visit extension.umaine.edu. Find more of our publications and books at extension.umaine.edu/publications/. Other Name: Dibotryon morbosum Pathogen: Apiosporina morbosa Introduction Figure 1. Black Knot causing a sharp bend
