Southern blight of pepper and tomato thrives under hot, dry conditions. Usually, such conditions are more likely in August. Production under tunnels may contribute to the dry conditions that influences southern blight. This article will discuss the symptoms, biology and management of southern blight of tomato. Southern blight has a wide host range affecting many vegetable, field and ornamental crops. Tomato is the most important host. The disease is caused by the fungus Sclerotium rolfsii. This fungus is related to the one that causes white mold.The first symptom one is likely to observe of southern blight is plant wilt. At the base of the plant, one is likely to notice a canker with sclerotia that may be as large as a sesame seed (Figure 1). These sclerotia are survival structures for the fungus and allow the disease to occur in the same location years later. The sclerotia for southern blight are round,[Read More…]

Tomato spotted wilt virus can cause stunting (Figure 1), necrotic ring spots (Figure 2), mottling (Figure 3) or chlorosis (Figure 4). In Figure 5, a pepper plant is shown with a ring-like lesion due to tomato spotted wilt virus. Figure 6 is a photo of a pepper transplant with mottled lesions due to impatiens necrotic spot virus. Both TSWV and INSV can cause symptoms on many hosts including ornamentals. Figure 7 is a photo of INSV symptoms on begonia. For more information about the biology and management of these diseases see here.