Today’s disease photo comes courtesy of Dr. Dale Pollet. This is foamy canker (or alcoholic flux), a disease that occurs on a number of tree species, but is most commonly seen on elm, oak, sweet gum and Victorian box. The white frothy, foam that is characteristic of this disease has a slightly alcoholic or fermentative odor and occurs only briefly during warm weather. The disease is presumably caused by bacteria or yeasts that invade cracks, holes or other injuries to the bark of trees where they grow. In some cases, the cambium beneath will be decayed as well. The only suggested treatment for this is to remove the bark from the affected area to expose it to the air and allow it to heal normally. In severe cases, the tree needs to be removed.
Donald M. Ferrin, Ph.D., Louisiana State University Agricultural Center, Baton Rouge, LA