Tomato spotted wilt virus (abbreviated TSWV) is deadly for tomatoes and up to 800 other plants, too.
TSWV (Bunyaviridae: Tospovirus) is different from most tomato diseases because it is caused by a virus, rather than a fungus or bacteria.
The culprit? Thrips (Thysanoptera: Thripidae), which are small flying insects that contract the virus as larvae and transmit it to plants as adults, when they’re feeding. Thrips prick the leaves, suck the contents, and transfer the virus in the process.
The disease was detected in Australia in the early 1900s and spread fast to temperate, subtropical, and tropical regions around the world.
You can recognize it easily in the red and yellow concentric rings on tomatoes. And by the fact that the plant wilts and dies within a few weeks (it’s a tomato wilt, right?)
Look for these symptoms, too.
TSWV symptoms begin on the top leaves first, while other wilts affect lower leaves and then move upward.
Leaves are bronzed, especially on the upper sides
Spots on leaves appear after bronzing
Spots on fruit have concentric rings
To date, there is no chemical treatment available. Destroy infected plants immediately.
You can take steps to prevent tomato spotted wilt virus and keep it from spreading to other plants.
Control weeds. By far, the most effective means of controlling the virus is in driving away thrips. These annoying pests live and feed in large groups, overwintering in weeds growing around gardens. Remove as many of those opportunities as possible. Control weeds and volunteer plants in and around your garden.
Clean up debris. To reproduce, thrips cut slits in green stems and lay eggs inside. Discourage them by reducing the numbers of places they like to reproduce: green plant debris. Remove grass and clippings as soon as possible.
Plant disease-resistant varieties. If you live in an area noted for high incidence of TSWV or high thrips population, plant disease-resistant tomato varieties (noted with “TSWV” listed after the variety name on its label) including Amelia, Bella Rosa, Crista, Mountain Glory, Nico, Quincy, Red Defender, Southern Star, Talladega, and Top Gun.
Plant with care. Avoid planting tomatoes near other crops that are known to be already infected by the virus.
It attacks universally. Tomato spotted wilt affects crops, flowers, and weeds. It’s one of only a few plant viruses that doesn’t discriminate, affecting plants in your vegetable garden like onions, potatoes, eggplant, peanuts, peppers and of course tomatoes.
It’s not a death sentence for the season. The virus lives in insects – not the soil – so if you lose your tomato plants to TSWV early or mid-season, you can replant fresh, disease-free seedlings in the same garden plot.
More about Other Tomato Wilts
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