Southern Blight
Southern blight
Common name
Southern blight
Southern wilt
Southern stem rot
Southern root rot
Causal agent
It is caused by a soil-borne fungus belonging to the genus Athelia.
Scientific name
Sclerotium rolfsii
Symptoms & Signs
The fungus usually attacks the lower stem near the soil first. However, other parts, such as seedlings, roots, flowers, and fruits, may also be affected. A brown or black lesion appears near the lower stem that grows to girdle the entire stem, resulting in root rot, leaf spots, and plant wilting. The lesions display white mycelium with reddish sclerotia. Infected fruits also have water-soaked, star-shaped lesions.
Transmission
The infection commonly spreads by the movement of soil or plants through infected tools and irrigation. Moist weather conditions with high temperatures between 77 to 95 ℉ favor the growth of this fungus.
Time of concern
Early to mid-summer
Common hosts
Tomato
Pepper
Bean
Watermelon
Cotton
Tobacco
Carrot
Petunia
Rose