Tree Diseases: Dutch Elm Disease

Introduction Dutch elm disease is a fungal infection that affects many species of elm. It is one of the most destructive tree diseases in North…

Tree Diseases: Gall Producers

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…

Tree Diseases: Galls on Plants

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…

Tree Diseases: Cedar-Apple Rust

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…

Tree Diseases: Canker Diseases

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…

Tree Diseases: American Chestnut Blight

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…

Tree Diseases: Sooty Mold

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…