It is also helpful to rogue and remove infected corms. Husks on infected corms are darker in color and dull in contrast to the sheen of healthy corms. Chemical controls are not effective for these fungi. Storage rots, Penicillium spp. Corms may become soft during storage or appear to be covered with bluish-green masses of fungal growth.
Control involves careful selection of clean, well-ripened corms for storage during digging.
These corms should be cured for three weeks at 80 F, with artificial heat if necessary. It is also helpful to carefully inspect the corms after storage and to destroy any corms that don't appear healthy. The first symptom of infection is the appearance of tiny, reddish-brown, raised dots on the basal part of the leaves. These spots enlarge and coalesce to form longitudinal lesions or streaks. Under favorable weather conditions, large, brown, dried areas develop on the leaves.