Fiji disease of sugarcane

Fiji disease of sugarcane is a serious viral disease caused by the Fiji disease virus (FDV), a member of the Fijivirus genus within the Reoviridae family. The virus is a systemic pathogen that disrupts the normal growth and physiological development of the plant, significantly impacting productivity in sugarcane-growing regions worldwide.

The primary host is sugarcane (Saccharum species). The disease is transmitted primarily by leafhopper vectors, most notably Perkinsiella saccharicida. Additionally, the virus is spread through infected vegetative cuttings (setts), which serve as a major pathway for transmitting the infection to new fields and distant geographic areas.

The most distinctive symptom is the appearance of small, elongated galls on the underside of leaf blades and along the leaf sheaths. Infected plants often exhibit stunted growth, shortened internodes, and stiff, deformed, fan-like leaf arrangements. In severe cases, the entire plant structure is compromised, leading to a condition commonly referred to as "stunting disease."

The development and spread of Fiji disease are heavily dependent on environmental conditions that favor the vector's life cycle. Warm and humid climates promote the rapid multiplication of leafhoppers, which facilitate the transmission of the virus. Once a plant is infected, the virus spreads throughout its vascular system, ensuring permanent systemic colonization.

The economic impact of Fiji disease is severe, characterized by significant yield losses and reduced sucrose content in the stalks. When infection levels are high, the crop's ability to ratoon (regrow after harvest) is diminished, often leading to the eventual abandonment of infected fields due to poor economic returns.

Effective management strategies require an integrated approach focused on exclusion and resistance:

• Use of disease-free, certified seed cane for planting.
• Breeding and cultivation of resistant or tolerant sugarcane varieties.
• Systematic roguing and destruction of infected stools to reduce virus inoculum.
• Monitoring and management of leafhopper vector populations using integrated pest management (IPM) techniques.
• Implementation of strict quarantine protocols for the movement of sugarcane germplasm.