Red ring

Red ring disease is a devastating condition affecting coconut palms and various other palm species in tropical regions. The disease is caused by the nematode Bursaphelenchus cocophilus, which invades the vascular system of the host plant. This infection leads to a severe disruption of water and nutrient transport, resulting in rapid decline and death.

The primary host is the coconut palm (Cocos nucifera), although the pathogen also affects oil palms and several ornamental varieties. The disease is particularly prevalent in Central and South America and the Caribbean, causing significant economic impact on the plantation sector and the production of coconut products.

Transmission occurs primarily through the palm weevil Rhynchophorus palmarum. The nematode uses this insect as a vector, hitchhiking into the palm tissue during the weevil's feeding or oviposition activities. Once inside, the nematodes multiply and move through the vascular bundles, causing the characteristic necrotic red-brown ring visible on the cross-section of the palm trunk.

Clinical symptoms include the progressive yellowing and browning of leaves, which typically starts with the older fronds. The tree's growth slows significantly, fruit yield drops, and eventually, the entire crown withers. Because the vascular system becomes blocked, the tree loses the ability to sustain itself, often leading to death within a few months of initial infection.

• Systematic removal and incineration of all symptomatic palms.
• Management of the Rhynchophorus palmarum weevil population.
• Deployment of pheromone traps to monitor and reduce vector density.
• Strict quarantine protocols to prevent the movement of contaminated material.
• Regular surveillance of plantation health.

Currently, there are no curative treatments available for infected palms, making prevention the only viable management strategy. Agrotechnical efforts are focused on rapid detection and the elimination of sources of infection to stop the vector-driven cycle of the nematode throughout the plantation environment.