Tomato leaves with mottling and fruit with necrotic spotting and ringspots were observed on a plant. These symptoms are typical of what occurs with a virus. This Alert will aid in the identification of a tomato spotted wilt virus (TSWV) infection in tomato.
A few containers with tomatoes were being grown outside of a greenhouse. There were some discolored leaves on one of the plants. Upon closer inspection, a few of the shoots had yellow leaf spotting and distorted growth. Ringspots were not observed on any of the leaves. The plants had a heavy fruit set. Most of the tomato fruits had necrotic areas. A close-up of the necrotic areas on a fruit and raised rings can be seen on the fruit surface. Necrotic ringspots are more clearly visible on the ripening fruit. No Western flower thrips (WFT) were observed on the leaves. This Alert can be used as a visual tool for diagnosing TSWV symptoms on tomatoes.
The leaves were tested for tomato spotted wilt virus (TSWV) and it was confirmed with an enzyme-linked immunosorbent assay (ELISA) test. In addition, we tested samples from the fruit by carefully taking a slice of the peel and a limited amount of the interior cells. (Sampling too much plant material can negate the test.)
Read more at e-gro.org