Silver leaf fungus

Silver leaf fungus (Chondrostereum purpureum) is a basidiomycete fungus belonging to the family Cyphellaceae. It is a well-known plant pathogen responsible for the disease called "silver leaf," which severely impacts the vitality and longevity of various woody plants worldwide.

The host range is broad, significantly affecting Rosaceae family members, particularly plums, cherries, apples, and pears. The fungus acts as a wound pathogen, typically invading the host through pruning cuts, branch breakage, frost damage, or other mechanical injuries in the bark.

The life cycle involves the production of spores by purple-brown, shelf-like fruiting bodies found on dead or decaying wood. These spores are wind-dispersed and land on susceptible wounds, where they germinate and colonize the sapwood. The mycelium secretes toxins that travel up the transpiration stream, causing the characteristic silvering of leaves.

The harm caused by this pathogen is progressive, leading to necrotic wood discoloration and eventual dieback of branches. In advanced stages, it can kill an entire tree. Its ability to survive on deadwood as a saprophyte makes it a persistent threat in orchards and forest environments.

Effective control relies on cultural practices rather than direct chemical intervention. Key strategies include pruning during dry weather to minimize spore entry, immediate removal and destruction of infected wood, and the application of wound protectants. Promoting general tree health through proper fertilization and watering is also essential to improve defense mechanisms.