Tulipa: Virus

Problem
Flowers are streaked, spotted, or mottled in an irregular pattern. The leaves may also be streaked or mottled with light green or white. The plant may be stunted and low in vigor.

Analysis
Several plant viruses commonly infect tulips, causing a characteristic streaking or mottling of the flowers and foliage. Infection may be accompanied by stunted growth. Virus infections rarely cause the plant to die, but can weaken it seriously. The viruses increase in the bulbs year after year. Successive plantings from diseased bulbs yield infected flowers and foliage of poor quality. Some viruses are spread by aphids. These insects feed on diseased plants and transfer viruses to healthy plants at subsequent feedings. Sometimes tulips are intentionally infected to produce showy flowers.

Solution
Once the plant is infected, no chemical will control the virus. To prevent the spread of the virus to healthy tulips, remove and destroy infected plants and all the bulbs associated with that plant. Keep the aphid population under control by spraying with an insecticide containing acephate. Because these viruses may also infect lilies, avoid planting tulips near lilies. (For more information about controlling disease-carrying insects, see Vectors of Plant Diseases.) Parrot tulips may exhibit showy streaked patterns, but the streaking is genetic in origin and cannot be transferred to other tulips and lilies.