Also known as Southern blight
Athelia rolfsii (Curzi) Tu & Kimbrough [teleomorph]
Sclerotium rolfsii Sacc. [anamorph]
- Symptoms: If infection occurs early in the crop cycle, pre- or post-emergence "damping off" of seedlings can result. Diseased tissues will frequently have white, fluffy fungal mycelia on the surface (picture at right), which often permeate the soil surrounding the plant. Subsequent disease development results in rotted culms, crowns, and roots, and the eventual death of the plant; this leads to the appearance of "white heads" or spikes in the green crop (picture at left). Sclerotia are commonly found on the crown tissues, culms, or near the soil surface (picture at bottom left). Young sclerotia are whitish and turn brown to dark brown with age.
- Development: Sclerotium wilt can attack the plant at any stage of development. Fungal mycelia on crop debris or sclerotia serve as primary inoculum. Infection and disease development are favored by warm (20°C +) temperatures, excessive moisture, and acid soils.
- Hosts/Distribution: Most cereals and grasses, plus many broad-leaf plant species are susceptible, and the fungus is widespread in tropical and subtropical environments.
- Importance: The disease is seldom a problem in traditional wheat-growing areas.
