Root and rhizome rot of banana

Pathogen and disease type
Root and rhizome rot, caused by the fungus Cylindrocarpon musae, is a significant soil-borne disease affecting banana crops. The pathogen is a facultative parasite that persists in the soil for extended periods through durable structures called chlamydospores, allowing it to survive in the absence of a host.

Affected crops
The primary host of this pathogen is the banana plant (Musa spp.). The disease is particularly destructive in intensive commercial banana plantations, where high-density planting facilitates the rapid spread of the fungus among root systems.

Symptoms and signs
Initial symptoms typically include chlorosis and wilting of the lower leaves. As the disease progresses, the root system undergoes severe necrosis, turning dark brown or black. A cross-section of the rhizome reveals extensive internal rotting and softening of the tissues, which severely compromises the plant's structural integrity and ability to transport water and nutrients.

Conditions for development and spread
The development of Cylindrocarpon musae is favored by poorly drained soils and excessive moisture. The fungus often exploits existing wounds in the roots, frequently caused by root-knot nematodes or mechanical damage during cultivation. Spread is facilitated by contaminated planting material, irrigation runoff, and movement of infested soil on farm machinery and tools.

Harmfulness and protection measures
The disease results in stunted growth, reduced bunch weight, and often total plant death, causing significant economic losses. Management strategy focuses on:

• using pathogen-free tissue-cultured plantlets;
• improving field drainage to prevent waterlogging;
• sanitizing equipment regularly to avoid cross-contamination;
• applying systemic fungicides to the root zone where infestation is confirmed.