Gall diseases are common on many trees and shrubs. Galls are abnormal swelling growths that form on the leaves, twigs, branches, roots, and flowers of plants. There are myriad gall…

Introduction Galls are abnormal swelling growths that occur on the leaves, twigs, branches, roots, and flowers of plants. A gall's characteristics are determined by its causal organism. They vary in…

Introduction Cedar-apple rust is a fungal infection that commonly affects junipers, apples, and crabapples. It is caused by a pathogen called Gymonosporangium juniperi-virginianae. Cedar-apple rust requires two hosts to complete…

Introduction Canker diseases are symptomatic of an injury associated with a plant that has become infected by a fungal or bacterial pathogen. Canker diseases frequently kill branches, and cause extensive…

Introduction Chestnut blight, also called chestnut bark disease, is a fungal infection that has significantly reduced the chestnut population in North America. The fungus is spread by wind-borne ascospores and…

Introduction: Sooty mold is a collective term applied to several species of dark fungi. The fungi grow on honeydew excreted by insects, or exudates from leaves of certain plants. Sooty…