White Mold
Sclerotinia sclerotiorum, Sclerotinia minor
Overview
A fungal disease affecting many broadleaf crops, producing white, cottony mycelium and hard, black sclerotia on infected tissue. Also known as Sclerotinia rot, timber rot, or lettuce drop.
Symptoms
Water-soaked lesions on stems, leaves, and pods that become covered with white, cottony mycelium. Hard, black, irregularly shaped sclerotia (3-10mm) form inside and on infected tissue. Wilting and collapse of plants.
Environmental Conditions
Cool
Prevention
Rotate with non-host crops (grasses, corn). Increase row spacing for air circulation. Avoid excessive nitrogen. Irrigate carefully to minimize leaf wetness. Use biological seed treatments.
Management
Apply Coniothyrium minitans (biological control) to soil before planting. Remove infected plants. Improve air circulation. Avoid overhead irrigation. Deep tillage to bury sclerotia.