Curly Top

Asked July 3, 2020, 10:54 PM EDT

Tonight, for the second time this year, I pulled up my five tomato plants due to what I believe was curly top virus. I won’t be doing a third planting. My wife and I are devastated. How can we prevent this next year when we try again?

Polk County Oregon

3 Responses

That is very disheartening since tomatoes are the heart and soul of a summer garden. However, I wonder if what you thought might be tomato curly top virus is truly physiological leaf roll. We really haven’t had the weather conducive to the curly top virus, but we are seeing a lot of the leaf roll right now. Here are two OSU publications one on tomato curly top virus, and the other one on physiological leaf roll. The final paragraph on page 3 details how to distinguish physiological leaf roll from infectious diseases such as curly top virus. The publication on curly top virus explains steps that can be taken to mitigate problems next year.

If you want to know for sure that your plants have a virus, then you may send a plant sample into the OSU Plant Clinic. The website has details on how to submit a sample.

Thank you for your prompt reply.

We had already referenced both of the documents you cited when we investigated the problem. We dismissed physiological leaf roll because the article states that it starts in the leaves at the bottom of the plant. In our case, all the curling was in the upper leaves. Also, we noted purpling in some of the stems, as described in the curly top document. I have uploaded a picture ofOne of the plants as an example.

As noted some tomato symptoms such as the leaf rolling can have several different causes. The only way to confirm a virus is to send a sample into the OSU Plant Clinic. The fee is modest and worth the peace of mind.

Let’s work on improving the general health of your garden soil to minimize diseases. One way to help your plants is to practice crop rotation. This short fact sheet from Ohio State University gives complete details. It boils down to planting families of plants in different areas of the garden each year so there isn’t a buildup of pests and diseases.

Another action is that you can send a soil sample into a lab to determine what nutrients are needed. Here is “A guide to collecting soil samples for farms and gardens” from OSU Extension. Here is a list of “Analytical laboratories serving Oregon.” It is a simple process, not very expensive, with useful information as a result. They can give you soil improvement recommendations.

Now that the soil is as healthy as possible, the next step is to grow resistant cultivars of tomatoes. At the end of the curly top virus page is a list of tomato cultivars that are resistant to tomato curly top virus. You will have to search for the seeds and grow your own seedlings as it is unlikely that they will be readily available in local nurseries.

Best of luck for your future tomato growing.