Cassava vein mosaic virus

Cassava vein mosaic virus (Cavemovirus venamanihotis) is a significant viral pathogen affecting cassava plants (Manihot esculenta). Classified within the Caulimoviridae family, this virus poses a constant challenge to tropical agriculture, directly impacting the yields of roots that serve as a primary starch source for millions of people worldwide.

The virus strictly targets cassava crops. Once a plant is infected, the pathogen moves systemically throughout the vascular system. This systemic spread leads to physiological stress, reducing the overall photosynthetic capacity of the foliage and directly stunting the development of the tuberous roots, which reduces commercial harvest quality.

The primary symptom is the distinctive mosaic or chlorotic pattern along the leaf veins, which appears as pale or yellowish streaks. Advanced stages of the disease may result in leaf malformation, puckering of the leaf surface, and a general reduction in plant vigor. Severely affected plants show significantly stunted growth and reduced biomass compared to healthy specimens.

Disease spread occurs through two main routes: the propagation of infected cassava stem cuttings and transmission by insect vectors. Mealybugs or other sap-sucking insects act as carriers, acquiring the virus during feeding and introducing it into healthy tissues. Because cassava is largely vegetatively propagated, infected planting material remains the most critical factor for widespread outbreaks.

Effective management focuses on integrated disease control strategies. Key preventive measures include:

• Selection of certified disease-free stem cuttings for planting.
• Establishment of nursery programs to maintain healthy germplasm.
• Rogueing of symptomatic plants immediately upon detection in the field.
• Vector management using biological or chemical control agents.
• Crop rotation and spatial separation from older, potentially infected fields.