Plant Diseases

Blight, Southern

Blight, Southern
Tap to view larger image
 
A soil-borne fungal disease that rots plant stems, southern blight thrives in the warm soils and wet weather of the South. It's also known as southern wilt, sclerotium root rot, and mustard- seed fungus; the last name refers to the organism's small, yellowish resting bodies. The fungus can survive for many years without a host.

Target: Many flowers and vegetables (especially peanuts and tomato-family plants); lawns.

Damage: White, cottony growth appears on plant stems near soil level and often spreads to the surrounding soil. As the flow of water through its stems grows progressively more restricted, the plant wilts, yellows, and ultimately dies.

Control: Crop rotation. soil solarization enriching the soil, aluminum foil collars, removing infected plants and soil, using landscape granules.

Notes: Plan a 2 to 3 year crop rotation, alternating susceptible plants with corn or other immune plants. Since nitrogen deficiency promotes the fungus, add organic matter to the soil and increase its nitrogen content. Protect plants by wrapping the main stems with foil from just above the roots to about 2 inches above the soil. Dig up and destroy infected plants, including at least 8 inches of soil on all sides.