Schizophyllum rot

Schizophyllum rot is a widespread wood-decaying disease caused by the basidiomycete fungus Schizophyllum commune. Known as the split gill fungus, this pathogen targets both dead wood and weakened living trees. It triggers a specific type of white rot, resulting in the rapid degradation of lignin and cellulose within the woody structure of the plant.

The fungus predominantly affects various deciduous trees, including popular orchard species like apple, plum, and peach. Infection usually occurs through exposed wood surfaces, such as pruning wounds, broken branches, or frost cracks. Once the mycelium gains entry, it colonizes the heartwood, slowly spreading outward and causing the structural integrity of the tree to fail over time.

The most distinctive symptom of the disease is the presence of small, fan-shaped fruiting bodies protruding from the bark. These mushrooms are typically greyish-white, with a fuzzy surface and gills on the underside that appear split—a key diagnostic feature. Internally, the affected wood turns bleached, light-colored, and brittle, often becoming spongy as the decomposition progresses.

Environmental conditions such as high humidity and stagnant air favor the growth and dispersal of the fungus. The spores of Schizophyllum commune are highly resistant to desiccation and extreme temperatures, allowing them to remain viable on surfaces for extended periods. Once released into the air, these spores can easily land on new wounds, perpetuating the disease cycle in orchards and urban forests.

Effective management and prevention of Schizophyllum rot are centered on wound care and hygiene. Growers should minimize large pruning cuts, and if they are necessary, seal the wounds with protective horticultural sealants or copper-based fungicides. It is also crucial to remove infected tree debris promptly, as decaying branches often serve as reservoirs for spore production that threatens healthy nearby trees.