Artificial heat for curing is advisable if the presence of Botrytis is suspected. Control can also be achieved with the use of fungicide sprays during the growing season. These can be applied as soon as symptoms are visible. Among the compounds registered for use in Connecticut are benomyl and thiophanate-methyl. Consult the label for dosage rates and safety precautions.
Symptoms show as paling and yellowing of leaves which progresses until the entire plant is dead.
Plants may wilt in the middle of the day and seem to recover at night. Some plants may show no signs of infection until they come into flower, when they suddenly collapse. Dead leaves may fall over or remain upright. Empty spaces in the row at digging time are usually due to this fungus. Corm infection shows as a brown rot at the basal plate extending upward, and if the corm is cut across, brown lines or streaks radiate from the core to the nodes.