Pink disease fungus

Corticium salmonicolor is a pathogenic basidiomycete fungus known to cause a serious condition in woody plants widely referred to as pink disease or pink limb blight. This pathogen is particularly destructive in tropical and subtropical agriculture, significantly impacting the health and productivity of various woody hosts across the globe.

The fungus affects a broad spectrum of commercial crops, including rubber trees, citrus, cocoa, coffee, and tea, as well as many fruit-bearing trees. The primary symptom is the appearance of a salmon-pink or dusty-pink mycelial mat on the surface of branches and stems. As the infection progresses, the bark becomes brittle and cracks, often leading to girdling, branch dieback, and, in severe cases, the death of the entire plant.

The life cycle of the pathogen involves both mycelial growth and the production of spores, primarily basidiospores and conidia. These spores are disseminated via wind currents and splashing water during rainfall events. Upon landing on a suitable host, particularly near existing wounds or crevices in the bark, the spores germinate and colonize the host tissues, establishing the infection site.

Environmental conditions play a decisive role in the virulence and spread of Corticium salmonicolor. High relative humidity and frequent rainfall are essential for the fungus to thrive, with optimal temperatures usually ranging from 25 to 30 degrees Celsius. In dense orchards, where air circulation is restricted, the pathogen can quickly transition from isolated infections to widespread outbreaks.

Effective management and control strategies rely on a combination of cultural and chemical interventions. Key practices include:

• Pruning and destroying infected branches to reduce the inoculum load.
• Applying copper-based fungicides to the affected areas and as a preventive measure during high-risk seasons.
• Maintaining proper spacing between plants to enhance canopy ventilation.
• Monitoring plantation health to detect early symptoms, as timely intervention significantly improves the chances of saving the tree.