Originally prepared by Nancy Kokalis-Burelle, Graduate Assistant, Plant Pathology. The host range of the fire blight pathogen includes nearly 130 plant species in 40 genera. Badly diseased trees and shrubs are usually disfigured and may even be killed by fire blight. Include Fire Blight Susceptible Cultivars. The term fire blight describes the blackened, burned appearance of damaged flowers, twigs, and foliage.
Symptoms appear in early spring.
Blossoms first become water-soaked, then wilt, and finally turn brown. These symptoms are often referred to as blossom blight. The blossom blight phase of fire blight affects different host plants to different degrees. Fruit may be infected by the bacterium directly through the skin or through the stem. These mummies often cling to the trees for several months.