Cassava frogskin disease

Cassava frogskin disease (CFSD) is a significant viral condition affecting cassava plants (Manihot esculenta). The disease is associated with a Phytoreolike virus, which interferes with the plant's physiological processes, causing severe stunted growth and abnormal development of the storage roots.

The disease primarily targets cassava. The hallmark symptom is the alteration of the root bark, which becomes thickened, corky, and rough, resembling the skin of a frog. Affected tubers are often distorted, significantly reduced in size, and display irregular cracking, making them commercially unviable and nutritionally inferior.

Transmission of the pathogen occurs mainly through the exchange of infected stem cuttings, which act as primary carriers of the virus. Insect vectors, specifically leafhoppers, play a crucial role in spreading the disease within fields. Warm weather conditions and high humidity facilitate the movement of these vectors, exacerbating the spread of the virus.

The economic impact of the disease is severe, as it leads to substantial yield losses in affected cassava-growing regions. Since the symptoms are often hidden underground until the harvest, farmers may unknowingly propagate the virus from one season to the next, causing a cumulative decline in the health and productivity of the entire plantation.

Effective management requires a multi-faceted approach aimed at prevention and containment:

• Using only certified disease-free planting material.
• Implementing rigorous sanitation practices, including the removal of infected plants.
• Applying heat therapy (thermotherapy) to stem cuttings to eliminate the virus.
• Managing insect populations, particularly vectors, through systematic monitoring and control.