Main symptoms

The Tomato spotted wilt virus (TSWV) causes a multitude of small necrotic lesions light brown with black on young leaves and petioles (Figure 1).

Old leaves show chlorotic spots becoming necrotic and brown in color (Figure 2); the leaf blade may also wilt on the periphery and turn yellow. These alterations extend; later, large areas of the leaf blade necrotize. In some cases, the leaves are more or less deformed.

Early infected plants show reduced growth and often die. If they survive, the head does not take place. Their leaves also reveal a bronze tint (Figures 3 and 4). Secondary microorganisms, especially bacteria, colonize the damaged tissues and cause their decomposition.