Oyster mushroom

The genus Pleurotus, while primarily known as edible mushrooms, can function as an opportunistic pathogen for trees. In professional horticulture, these fungi are often considered agents of white rot, targeting the woody tissues of various tree species.

The causative agent is the fungal mycelium that invades the host through bark wounds, pruning cuts, or frost cracks. Once established, the fungus initiates a type of rot that degrades cellulose and lignin, effectively transforming the structural integrity of the timber.

Fruit trees such as apple, pear, and plum are susceptible, especially when their vigor is compromised by environmental stress or old age. The disease often progresses silently inside the trunk before the formation of visible fruiting bodies confirms the infection.

Symptoms include the emergence of characteristic shelf-like sporocarps and the internal degradation of wood, which turns brittle and pale. The harmfulness lies in the gradual weakening of the tree, ultimately leading to mechanical failure and the premature death of the specimen.

• Monitor tree trunks for signs of fungal brackets.
• Sanitize all pruning tools to prevent spore transmission.
• Treat open wounds and deep cuts with specialized wound dressings.
• Remove and dispose of decayed wood to prevent secondary infection.

Integrated management is essential, as there are no direct curative fungicides for established internal rot. Maintaining proper tree vitality through balanced nutrition and minimizing mechanical injury remains the most effective strategy against Pleurotus infestations in the field.