Plant where the soil and air drainage is good. Destroy diseased plants. Wilt causes leaves of infected plants to yellow and the stems to collapse. Mildly infected corms may not show symptoms when dug but may rot in storage. The disease is caused by Fusarium orthoceras.
Smut causes blistering, shredding and dying of stem and leaf tissue.
Leaf and flower spot causes oval, tan to dark brown spots on the leaves and stems. Florets on heavily infected plants do not open. The disease is caused by Curvularia trifolii. Several virus cause color breaks in the flowers. There is no chemical control.