Corallomycetella elegans

Corallomycetella elegans (formerly known as Nectria rigidiuscula) is a fungal pathogen responsible for various wood-rotting diseases and bark necrosis in tropical and subtropical tree crops. As a significant phytopathogen, it plays a detrimental role in the health and productivity of diverse agricultural and plantation ecosystems.

This pathogen primarily targets trees such as cocoa, coffee, and rubber. Infection usually occurs through wounds, pruning cuts, or galleries created by wood-boring insects. While it can exist as a saprophyte on dead tissue, it frequently transitions to a parasitic state, especially when tree defenses are compromised by abiotic stress or previous infestations.

The primary symptom is the development of necrotic lesions on the bark and branches. Under favorable environmental conditions, the fungus produces distinctive coral-red or orange-colored stromata on the bark surface. As the infection progresses, the cambium tissue is destroyed, leading to the blockage of vascular bundles, branch dieback, and eventually the death of the host plant.

The development and spread of Corallomycetella elegans are heavily dependent on humidity and rainfall, which facilitate spore dispersal via wind and water splashes. Insects often act as primary vectors, carrying spores directly into the fresh wounds they create on the tree bark. Therefore, poor orchard sanitation and insect infestation levels are directly correlated with the severity of the disease.

Effective management and prevention strategies include:

• Regular removal and destruction of infected branches and debris.
• Application of protective wound dressings to pruning sites.
• Integrated pest management to reduce insect-related damage.
• Proper fertilization to ensure high plant vigor and resistance.
• Chemical control using copper-based fungicides during high-risk rainy seasons.