Bulbs may be stressed from transplanting. Some varieties bought from a grower in one climate may have a difficult period of adjustment to a vastly different climate. Some naturalized varieties growing well in one region do not grow well in regions with different climate. The bulbs may be viruses. Over time, an infected plant loses its vigor, puts up smaller, weakened leaves and stems, stops blooming, and finally dies.
Yellow stripe shows as fine streaks of yellow the length of the leaves.
It appears as the leaves emerge. The plant is weakened by the second year. Mosaic only appears as white blotches on the yellow flowers where the petals lose their color. Plant vigor seems unaffected. Both these diseases are contagious to other daffodils and incurable.