Tomato ringspot tospovirus

Pathogen and type of disease
The Tomato ringspot tospovirus (Orthotospovirus tomatozonae) is a member of the Tospoviridae family. It is a highly contagious systemic viral disease that disrupts the normal development of plant tissues and causes severe physiological disorders, leading to significant physiological stress for the host plant.

Host range
While primarily identified as a threat to tomatoes, the virus has a wide host range. It frequently infects a variety of vegetable crops, ornamental plants, and common agricultural weeds. These weeds often serve as environmental reservoirs, allowing the virus to survive between crop cycles.

Symptoms and signs of infection
Infected plants display distinct symptoms, including ringspot patterns and chlorotic lesions on the foliage and ripening fruits. The leaves may show deformation and mosaic patterns, while the stem can exhibit necrotic patches. Severely affected plants show stunted growth and fail to produce viable yields.

Conditions for development and harmfulness
The virus is transmitted by thrips, particularly the western flower thrips. Disease transmission is closely linked to the population density of these vectors. The virus is economically devastating, as it can cause total yield loss in susceptible varieties, rendering the harvest unmarketable and weakening the overall vitality of the crop.

Protection and preventive measures
Management relies on integrated pest management practices:

• Strict control of thrips populations using targeted insecticides and biological traps.
• Use of virus-free certified seeds and resistant cultivars where available.
• Rigorous weed management in and around the greenhouse or field area.
• Sanitation procedures, including cleaning tools and removing infected plants to stop the spread.
• Implementing buffer zones to reduce the risk of secondary infections from neighboring fields.