Tomato bushy stunt virus

Taxonomy and nature of the pathogen. Tomato bushy stunt virus (TBSV) is the type species of the genus Tombusvirus within the Tombusviridae family. It is a non-enveloped, icosahedral virus containing a positive-sense single-stranded RNA genome. It is widely recognized as a severe plant pathogen capable of causing significant economic losses in various agricultural sectors.

Diseases and host plants. The virus affects a wide range of host plants, including tomatoes, peppers, eggplants, grapes, lettuce, and petunias. It causes typical stunting symptoms, from which the name originates. Plants exhibit distorted leaves, chlorotic or necrotic spots, reduced internode length, and significantly smaller, poor-quality fruits compared to healthy plants.

Biology and life cycle. Unlike many other plant viruses, TBSV is not dependent on insect vectors for transmission. It is highly stable and can persist in soil, irrigation water, and crop residues for extended periods. It is primarily transmitted mechanically through root contact, contaminated tools, pruning wounds, or infected seeds and pollen, allowing it to spread rapidly through greenhouse environments.

Development and impact. Development is favored by moist soil conditions. The impact of the virus is high because it systematically colonizes the plant, leading to total yield loss in severe cases. The virus is particularly hazardous in intensive greenhouse operations, where it can easily be transferred between plants during routine cultivation and harvesting activities.

Control and management. Since there are no antiviral treatments for infected crops, management relies on stringent hygiene and cultural practices:

• Regular disinfection of all tools, equipment, and irrigation systems.
• Soil sterilization (steam or chemical) before planting in greenhouses.
• Strict exclusion of weeds and host reservoirs around the growing area.
• Use of virus-indexed, certified disease-free seeds and transplants.
• Immediate removal and destruction of symptomatic plants to prevent further spread.