Diary of an Average Gardener

Tomato Spotted Wilt Virus

– Posted in: Garden Tips and Info

Tomato Spotted Wilt Virus

I check out my garden every morning and it’s a good thing I do. In early June I found a couple of my tomato plants that had some brownish spots and brown areas on the leaves. Most of the leaves were on the top of one plant. On closer examination I found similar spots on a couple of other plants. The location of the leaves varied, some on the bottom, some on the ends of of random stems. I had not seen this discoloration before so I took some of the infected leaves to my local extension office, Forsyth County Georgia Extension Office, part of University of Georgia Department of Agriculture. Two very helpful master gardeners helped me identify the problem: Tomato Spotted Wilt Virus (TSWV). OK a virus….just like in humans a virus spreads rapidly and there’s no antibiotic to cure it There are only ways to control it.Tomato spotted wilt virus

thrips

The tomato spotted wilt virus is spread by thrips, a small common insect, approximately 1 mm in length. NBeing so small, they are typically carried by the wind. There are over 5000 varieties of thrips and over 1000 known host plants. The virus may appear differently on different types of plants.

This is a picture of the type I found on my tomato plants. The virus is spread during the larval stage. TSWV is acquired by thrips during the larval stage. Only immature thrips that have TSWV, or full grown thrips that acquired the desease during the larval stage, spread the virus. Once a plant is infected the virus then spreads through the plant.

How to Control Tomato Spotted Wilt Virus

This is the advice I received from the extension office…it worked.

  1.  Infected plants will most likely have thrips living on them. The best thing to do is to remove the plant from your garden, so that the thrips don’t get the chance to move to additional plants.  Pull it up, place it in a plastic bag, tightly close up the bag, and dispose of the bag. I did this to one plant that seemed to be infected the most.  I
  2. Or, You can also cut off all the leaves that you see that are infected and dispose of those in the same way. You may get lucky and avoid the virus from spreading through the rest of the plant……assuming the thrips have vacated.  I did this to two plants. One I left in its original location in the garden and the other I dug up and transplanted to a large pot which I moved away from the garden.  The one in the pot still seems to have the virus, as its top leaves are curled and I see small brown spots on some leaves. The one I left in the garden seems to be doing OK.  As I trimmed off most of its leaves, I wasn’t sure it would survive. I didn’t just trim….I cut off major stems that had infected leaves. It is growing new leaves and has small fruit. No other plants have shown signs of being infected with the Tomato Spotted Will Virus.
  3. Keep checking for signs of infection.

While I don’t seem to have any new signs of TSWV, I do have signs of Early and Late Blight. This is normal for my garden space,  There’s an additional post discussing what you can do about blight.Tomato Early Blight