By daughterson Black Knot Disease (Apiosporina morbosa) The problem with Black Knot disease is that the tree is infected with this fungus two years before you see any sign of the problem. The

Wayne F. Wilcox, Department of Plant Pathology, NYS Agricultural Experiment Station, Cornell University Black knot is a common and often serious disease of plum and prune trees in New York. Once es

Submitted by Meghan Shinn on March 8, 2011 – 8:00 am Question: Our purple-leaf plum tree has a couple branches with a thick black crust covering a section of bark. I think it is black knot. How s

Black Knot On Plum And Cherry Trees Black knot, caused by the fungus Dibotryon morbosum, is a common disease of plum and cherry trees throughout the United States. The fungus attacks twigs and bran