PPDL Picture of the Week
March 18, 2019
Tomato spotted wilt virus
Dan Egel, Clinical Engagement Associate Professor-SWPAC, Botany and Plant Pathology, Purdue University
It is too early for tomato plants to be growing in the field in
Indiana. However, many growers across Indiana will be looking for an
early harvest by growing tomatoes in greenhouses. These structures provide
a warm environment to speed plant growth. However, some diseases and insects
may become more severe in a greenhouse.
Tomato spotted wilt virus (TSWV) often causes stunting and
ringspots on tomato foliage (Figure 1). Fruit can become distorted (Figure 2).
I usually see TSWV in greenhouses more than in fields. There are two reasons
for this observation. TSWV is a virus disease that is transmitted by a very
small insect known as thrips. Thrips may be washed off in the rain, but in a
greenhouse, thirps may be protected. And usually, the thrips get the virus from
ornamental plants such as flowers which may be grown together with tomato
The easiest way to avoid having your tomato plants get TSWV is to
grow tomato plants and flowers in separate greenhouses. A more complicated task
is to manage thrips. More details about managing thrips and TSWV can be found
in the Midwest
Production Guide for Commercial Growers.