Centrosema mosaic

The causative agent of the disease is Begomovirus centrosemae, a plant virus belonging to the Geminiviridae family. These viruses are characterized by a geminate capsid structure and a single-stranded DNA genome. The pathogen primarily affects leguminous plants, particularly species of the genus Centrosema, causing systemic infection that impairs the plant's physiological functions and metabolic processes.

Symptoms of the infection typically include characteristic mosaic patterns, leaf yellowing, and mosaic-like mottling on the foliage. Infected plants often show signs of leaf curling, stunted growth, and a reduction in the overall size of the leaf blades. In advanced stages of the disease, necrosis of the veins or leaf margins may occur, leading to a significant reduction in the photosynthetic capacity and vitality of the affected crop.

Transmission of the virus is primarily mediated by the whitefly vector Bemisia tabaci. This insect acquires the virus during feeding on an infected host plant through a persistent, circulative manner. Once the insect has acquired the virus, it remains a carrier for the rest of its lifespan, facilitating the spread of the pathogen across the field as the whiteflies move from plant to plant in search of food.

The spread and development of the disease are heavily influenced by the population dynamics of the whitefly vector, which thrives in warm and humid climates. High temperatures accelerate the life cycle of the whitefly, leading to rapid population surges. Additionally, the presence of alternate host plants, such as wild legumes or invasive weeds, ensures the survival of the virus throughout the year, serving as a continuous reservoir for further outbreaks.

The impact of this virus on agriculture is significant, leading to reduced yields and inferior plant quality. Management strategies focus on an integrated approach:

• Regular monitoring and control of whitefly populations using targeted insecticides.
• Removal and destruction of symptomatic plants to reduce local inoculum sources.
• Implementation of crop rotation and destruction of reservoir weed species.
• Utilization of virus-free planting material and resistant crop varieties.