Wet root rot

Wet root rot is a destructive plant disease caused by the fungal pathogen Ganoderma philippii. As a soil-borne fungus, it specializes in attacking the vascular systems of roots, causing systemic breakdown of tissues that effectively prevents the plant from absorbing essential water and nutrients.

The host range of Ganoderma philippii is broad, significantly impacting several economically important crops. Among the most susceptible are plantation crops like cacao and grain legumes such as chickpea and lentils. The pathogen is particularly devastating in warm and humid agricultural regions where it can persist in the soil for several years.

Symptoms of the disease are typically observed in the aerial parts of the host: chlorosis, wilting, and sudden death. Below ground, the roots exhibit distinct rot symptoms, including discoloration (turning dark brown or black) and the softening of the cortical tissue. In some instances, reddish-brown basidiocarps of the fungus emerge at the base of the infected plant.

The development of wet root rot is favored by high soil moisture, poor drainage, and warm environmental conditions. The fungus spreads rapidly through root-to-root contact, contaminated irrigation water, and the movement of infected soil debris. Because the fungus thrives in waterlogged areas, the presence of high-moisture zones significantly accelerates the disease cycle.

Integrated management is essential for controlling Ganoderma philippii, as chemical control alone is often insufficient. Effective strategies include:

• Sanitation by removing and burning infected plants and surrounding soil.
• Improving soil drainage to prevent the anaerobic conditions that promote fungal growth.
• Implementing rigorous quarantine procedures for planting material.
• Applying specific soil fungicides to manage potential outbreaks in early stages.