Introduction Brown spot needle blight is a fungal disease of pine trees. The disease is caused by the pathogen, Mycosphaerella dearnessii. The damage produced by brown spot needle blight resembles…

Introduction Powdery mildew is a fungal disease that affects a wide range of plants. It is caused by numerous fungi in the order Erysiphales, of which Podosphaera xanthii is the…

Introduction Nectria canker is one of the most serious diseases to afflict hardwood trees. The disease is caused by several species of Nectria. Nectria is a genus of Ascomycete fungi.…

Introduction Holly leaf spot, also referred to as holly tar spot, is a fungal disease that affects holly plants. Holly tar spot induces the formation of black spots on the…

Introduction Maple tar spot is a fungal disease that affects many species of maple. The disease occurs most frequently in North America and Europe. It is caused by three related…

Introduction Oak wilt is an aggressive tree disease that affects many species of oak. The causal agent of oak wilt is the fungus Ceratocytis fagacearum. Ceratocytis fagacearum is believed to…

Introduction Armillaria root rot, also called fungal root rot, or Armillaria root disease, is a plant disease caused by several members of the genus Armillaria. The fungus most often identified…

Introduction Crown gall is a tree disease of many woody shrubs, and some herbaceous plants. The disease is caused by the bacterium Agrobacterium tumefaciens, a soil-borne bacterium that is normally…

Introduction Bacterial wetwood, often referred to as slime flux, is a bole rot that afflicts hardwood trees. The disease is associated with numerous bacteria, which infect the inner sapwood, and…

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 America and Europe. Dutch elm…