There are several different viruses that affect tulips, each with slightly different symptoms. Tulip breaking virus causes streaking or marking of purple, pink and red tulips, usually on the late-flowering cultivars. White and yellow tulips aren't affected. The leaves can also be affected, with a general loss of vigour and poor flowering. Cucumber mosaic virus results in deformed plants and ruined or aborted flowers. Look out for sunken spots or ringed bulb scales on the stored bulbs. Tobacco necrosis virus affects mainly early flowering cultivars and produces brown-streaked stems and leaves.
Tulips display a range of symptoms from markings on the leaves and flowers with loss of vigour, to deformed plants and brown-streaked stems. Tulip bulbs appear rotten or pitted.
Dig up and destroy affected bulbs, and in the case of the tulip breaking virus don't plant your tulips near lilies, which can carry the virus without showing any symptoms. Avoid replanting where affected bulbs were growing.