A plant disease caused by the fungus stromatinia gladioli, which attacks corms in storage and the soil. Foilage turns yellow and dies. Leaf bases are rotted or shredded. Black spots of the fungus, which look like pepper, cover the leaf bases and corms.
Corms have dark brown to black lesions, which sink inward.
The lesions are dry, corky and may join together to destroy the entire corm. Fungi of this species penetrate root corms while in the ground or storage. Decay quickly spreads up into the leaf cases. Dry rot is most likely in corms that have been stored in moist conditions, or planted in wet, cold soil. The infection spreads through contaminated soil and corms.