Dematophora

Dematophora is a genus of fungi representing the anamorphic stage of the ascomycete Rosellinia necatrix. This pathogen is globally recognized as the causative agent of white root rot, a devastating disease affecting a diverse range of agricultural, horticultural, and forestry crops.

The fungus invades the root system, causing necrosis and decay of root tissues. Infected plants often exhibit symptoms such as reduced vigor, yellowing of leaves, premature defoliation, and eventual wilting. The disease is particularly destructive to fruit trees, including pome and stone fruits, as well as vines.

The biology of the pathogen relies on the formation of rhizomorphs—thick, white mycelial strands that grow through the soil to reach neighboring healthy roots. These structures, along with sclerotia, allow the fungus to persist in the soil for several years even in the absence of a host.

Development is favored by high soil moisture, poor drainage, and moderate temperatures. Dematophora thrives in compacted soil environments where the lack of oxygen and organic activity creates a niche for the pathogen to establish and spread effectively.

• Remove and burn infected plant debris and roots.
• Improve soil drainage to prevent waterlogging.
• Implement soil fumigation or solarization in affected areas.
• Use biological control agents to promote healthy soil microflora.
• Select resistant rootstocks where available.

Controlling the pathogen is challenging due to its soil-borne nature. Successful management relies on rigorous sanitation, prevention of soil compaction, and the application of integrated pest management strategies to limit the spread of mycelium in the root zone.