Black Knot of Plum and Cherry
Black knot of plum, caused by Dibotryon morbosum, occurs on cultivated plum and wild cherry (Fig. 36-1A). It is a common disease in northeastern and north-central United States. One cannot wander about the north woods without encountering it on wild cherry. The disease is of little economic importance and is easily controlled by removal of cankers in orchards and nearby wild cherry trees.