Tomato Spotted Wilt

Tomato spotted wilt is a viral disease spread by thrips.

Tomato spotted wilt (Scot Nelson) Public Domain

Besides tomatoes, this virus can infect chili peppers, eggplant, lettuces, radicchio, peanuts, and fava beans.

Pepper infected with spotted tomato virus (Carlos Gonzalez) CC BY-SA 3.0

Symptoms of tomato spotted wilt

When the tomato spotted wilt virus infects a plant, it blocks the flow of water and nutrients in the xylem, causing it to wilt. This viral disease also causes spots, stunted growth, a crumpled leaf appearance, leaf cupping, dead spots on leaves and stems, and overall discoloration.

Sweet basil infected with tomato spotted wilt (Scot Nelson) Public Domain

 Symptoms can vary depending on the plant’s overall health, the cultivar, environmental factors, and life stage at the time of infection:

• Infected seedlings end up severely stunted at what should have been their transplant stage.
• Leaf bronzing and petiole necrosis are common symptoms of plants infected during their vegetative stage.
• When infection occurs at the flowering or fruiting stages, fewer shoots develop, leaves curl, and may have yellow or purplish discoloration.
• Fruits are bumpy, deformed, and have visible ringspots.

This disease is easily mistaken for curly top and alfalfa mosaic virus. You can take samples to your County Extension Office, though the control measures are similar for all three diseases.


How tomato spotted wilt spreads

Thrips spread the tomato spotted wilt virus. These sap-sucking pests carry the virus with them. As they feed, they insert the virus. Many ornamentals and weeds, such as cheeseweed, sowthistle, bindweed, and prickly lettuce, are hosts for thrips infected with tomato spotted wilt.


Managing tomato spotted wilt

It is easier to prevent tomato spotted wilt. These tips can help reduce the chance of it occurring in your foodscape:

• Install resistant varieties.
• Quarantine new plants.
• Monitor plants closely for thrips to prevent the spreading of disease.
• Control thrips.
• Remove nearby weeds.
• Remove and compost exhausted tomato plants after harvest.
• Remove diseased plants and throw them in the trash.

May you never find tomato spotted wilt in your garden!