Rigidoporus vinctus

Rigidoporus vinctus is a wood-decaying fungus belonging to the Basidiomycota phylum, responsible for causing white root rot in various woody plant species. As a potent pathogen, it targets the lignin and cellulose within the host's root system, leading to rapid degradation of structural integrity and eventual decline of the entire plant.

The host range of this fungus is broad, primarily affecting tropical and subtropical agricultural crops such as Hevea (rubber tree), tea, coffee, and cocoa. It is also found in various forest tree species, where it functions as a primary pathogen capable of infecting both stressed and seemingly healthy trees in plantation settings.

Early symptoms include a general loss of vigor, chlorosis of leaves, and dieback of the canopy. As the infection progresses, trees show stunted growth. The diagnostic sign of the disease is the presence of the fungus's rhizomorphs or mycelial mats on the roots, followed by the appearance of perennial, tough, white-to-brownish fruiting bodies at the base of the infected trunk.

The development and dissemination of the pathogen are driven by environmental and biological factors. High soil moisture and warm temperatures create optimal conditions for mycelial growth. The fungus spreads rapidly through root-to-root contact in dense plantations and can persist for years in the soil on decaying stumps or woody debris, serving as an inoculum source for future infections.

Economic damage caused by Rigidoporus vinctus is significant, as infected trees become unstable and prone to windthrow. Effective management relies on strict sanitation protocols: removing symptomatic trees including the root stumps, isolating the infected area with deep trenches to prevent root contact spread, and applying appropriate fungicidal treatments to the soil to limit the pathogen's ability to survive in the rhizosphere.