Established plants rot at the crown.
Infected tissue is covered with dusty gray fungal growth.
Botrytis cinerea Maintain low humidity by spacing plants and venting to improve air circulation. Remove dead and dying flowers and leaves. To protect healthy plants, apply fenhexamid or fludioxonil. Mildew White fungal growth forms on the upper surface of leaves and may form on flower petals. Erysiphe cichoracearum Apply Ampelomyces , trifloxystrobin, or kresoxim methyl to protect plants.