Symptoms vary with the plant host and can lead to crown and stem cankers, root rots, wilts, damping-off of seedlings, and blossom and fruit rots. Plants can wilt rapidly as a result of stem-girdling cankers at or near the soil line. Brown spots can appear on flower petals and buds. Cottony masses of fungal threads (hyphae) may appear on stems or on nearby soil. Hard, irregularly-shaped masses (sclerotia) develop within or on the surface of infected plants. The sclerotia are white at first and then turn dark brown or black when mature. This disease favors cool wet springs and fall weather. Spores are dispersed primarily by wind, watersplash and insects.
Prune 4-5" below diseased tissue or remove entire, severely affected plants and burn them. Check seed for presence of sclerotia and remove them before planting. Promote good air circulation via proper plant spacing. Control weeds as they can be alternate hosts and can decrease air circulation. Avoid overwatering and frequent light waterings; water deeply early in the day. Remove and destroy dead leaves, withered flowers and other plant debris. In beds where white mold has occurred, remove and replace infested soil. Do not compost plant debris.
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