Mosaic Virus
A family of plant viruses transmitted primarily by aphids that cannot be cured once a plant is infected. Multiple species infect different hosts - Cucumber Mosaic Virus, Tomato Mosaic Virus, and Tobacco Mosaic Virus are among the most common. Management focuses entirely on prevention and immediate removal of infected plants.
Symptoms to Look For
- Mottled yellow and dark green patterning on leaves - the mosaic or marbling effect that gives the disease its name
- Leaves distorted, crinkled, puckered, or with an unusual bumpy texture
- Stunted, bushy growth with shortened internodes and reduced vigour
- Pale, mottled, or poorly-coloured fruit with poor flavour and reduced yield
- Overall plant stunting disproportionate to growing conditions
Affected Plants
Organic Solutions
Remove Infected Plants Immediately
There is no cure for mosaic viruses. Remove and bag infected plants immediately and place in household waste. Do not handle healthy plants after touching infected ones without washing hands with soap.
Rigorous Aphid Control
Since aphids are the primary vector, managing aphid populations is the most effective way to prevent mosaic virus spread. Encourage natural predators, use neem oil and insecticidal soap, and remove aphid colonies immediately when detected.
Disinfect Tools and Wash Hands
Tobacco Mosaic Virus can spread mechanically on hands and tools. Wash hands with soap between plants when pruning or training. Dip pruning tools in a 10% bleach solution between plants. Avoid smoking near tomatoes.
Prevention
- Use certified virus-free seed and purchase transplants only from reputable sources
- Control aphids from early in the season - even a single brief feeding event can transmit the virus permanently
- Grow resistant varieties of cucumber and tomato where mosaic virus is a documented problem in your area
- A garden with strong biological activity and diverse beneficial insects will have lower aphid populations and therefore lower virus transmission risk. Regular compost tea applications and a diverse flowering understory are your best preventive investment
Garden, by Willowbottom recommends only organic, wildlife-friendly solutions. No synthetic pesticides, no harmful chemicals - ever.