Daffodil (Narcissus)
Plant Health Problems
See Bulbs for a detailed discussion of problems that may occur and are common to most bulbs.
Diseases caused by Fungi:
Leaf scorch, Stagonospora curtsii.
This fungus infects leaves, flower stalks, flower parts, or bulb scales. Affected plant parts are often bent or deformed at the point of infection. Brown spots or blotches with yellow borders develop on diseased tissues. Flower stalks of plants with severe infections often dry up without producing flowers. Since the fungus is probably present in the bulb, infections occur as flower stalks and leaves emerge from the bulb.
Control can be achieved by minimizing moisture on the leaves and flower stalks by careful watering. It is also helpful to provide good ventilation and plenty of light since these will decrease the chance of spreading the fungus. Heavily infected bulbs should probably be discarded.
Bulb rot, Penicillium, Fusarium.
This disease often develops during storage and is frequently associated with mechanical injury or damage from mites. Infection is favored by moist conditions. Infected bulbs have a dry, punky bulb rot and the bulb scales are often covered with the characteristic blue-green (Penicillium) or pink (Fusarium) colored growth of the fungus.
Control is achieved through careful digging to avoid wounding. It is also helpful to control insect and mite pests. Infected bulbs should be destroyed.
Diseases caused by Physiological/Environmental Factors:
Flower blast, physiological.This trouble is fairly widespread and characterized by the appearance of flower buds which turn brown and dry up before opening. The cause is unknown but is thought to be related to weather.
Bulbs with this symptom year after year can be dug and discarded.
Insect Problems:
See Bulbs.