Cedar apple rust affects the foliage and fruit of apples (Malus domestica) and other members of the family Rosaceae (e.g. crabapple). This fact sheet describes the causal agent, the fungal pathogen, Gymnosporangium ...

Fire blight, caused by the bacterium Erwinia amylovora, is one of the most destructive diseases in apple and pear production. Fire blight can infect other members of the rose family including quince, juneberry, hawthorne, ...

Apple scab, one of the most devastating fungal diseases of apple, occurs worldwide, wherever apples are grown. The fungal pathogen, Venturia inaequalis, can also infect crabapple, hawthorn, mountain-ash, firethorn, and loquat.

Powdery mildew occurs in all apple-producing regions worldwide, especially where warm, humid climate conditions prevail. Young expanding plant tissues are particularly susceptible to the disease. Therefore, powdery mildew ...