Senna begomovirus

The disease type is a systemic viral infection. The virus localizes in the plant's phloem, disrupting the normal transport of nutrients.

The main vector (carrier) of the virus in nature is the tobacco whitefly, Bemisia tabaci. The insect acquires the virus while feeding on the sap of an infected plant.

The virus persists in the whitefly's body for a long time, remaining capable of transmission when the insect moves to healthy plants.

Mechanical transmission of the virus through tools or seeds for this species is extremely rare; the primary pathway is entomological.

The first sign of infection is characteristic leaf mosaic, manifesting as light green or yellow spots. Leaf tissue may become chlorotic.

Pronounced deformation of the leaf blade is observed: leaves curl, their edges roll inward or outward, taking on a corrugated shape.

Overall plant growth is slowed. Internodes are shortened, resulting in affected specimens appearing stunted compared to healthy plants.

There is a significant reduction in the quantity and quality of flowering. Flower buds may fall off without opening or develop with visible anomalies in shape.

• Yellowing of leaf veins
• Curling of young shoots
• Small leaf size (little leaf)
• Premature leaf drop

Disease development is directly dependent on the population density of the vector, the whitefly. Virus spread occurs most actively in hot, dry weather.

A temperature range of +25°C to +30°C is optimal both for whitefly reproduction and for the accumulation of the virus titer in plant tissues.

The presence of reservoir weeds capable of carrying latent infection or serving as a habitat for whiteflies accelerates the contamination of Senna plantings.

Dense plantings facilitate the rapid migration of insects from bush to bush, leading to a lightning-fast spread of infection centers across the field.

Poor irrigation and nutrition management weaken the plants' immune systems, making them more susceptible to systemic viral infection.

The harmfulness of Senna begomovirus lies in significant yield losses of medicinal raw materials (Senna leaves), which become unsuitable for processing.

Infected plants lose their ornamental and economic value. The quality of raw material drops sharply due to tissue necrosis and the loss of photosynthetic area.

In cases of massive infection, young plants may die, leading to sparse stands and the necessity for costly replanting of areas.

Economic damage includes not only yield losses but also expenses for constant monitoring and efforts to control whitefly populations.

Viral infection is practically impossible to treat with therapeutic agents, so affected specimens often become a source of infection for neighboring crops.

The main control measure is the elimination of virus vectors. It is necessary to timely apply insecticides against whiteflies, especially during their activity periods.

It is important to perform regular weeding of plants that may act as reservoirs for both the virus and insect pests during the off-season.

Using resistant varieties or hybrids is the most effective preventive method in regions endemic to the begomovirus.

Upon detecting the first symptoms of infection, affected plants should be immediately removed from the plot and disposed of through deep burial or burning.

Adherence to crop rotation rules and spatial isolation from other Solanaceae and Fabaceae crops helps reduce the risk of cross-infection through shared pests.