Club root causes abnormal root growth. The plants are stunted and wilt during the day but recover at night. Avoid planting where other crucifers have been growing. No chemical control is listed.
Downy mildew causes a light gray powdery growth on the undersides of leaves and on young stems. Infected plant parts may be distorted. Remove infected plants or plant parts. No chemical control is listed.
White rust symptoms are light yellowish discoloration of the leaves. The leaves turn brown in spots and white pustules form on the undersides of leaves. Badly infected plants may die. Remove and destroy infected plants and plant residues. No chemical control is listed.
Leaf spot causes small brown spots on the leaves during rainy weather. Control is seldom needed.
Blight or gray mold causes leaf and stem rot. Remove infected plants and plant parts. This disease can be controlled with benomyl.