Tops may appear water-soaked and collapse. Infected bulbs have a strong odor and are soft and mushy. Since this pathogen is highly contagious, all infected bulbs should be discarded. Bulbs should be planted in well-drained soil and watered early in the day. This disease can also be minimized by avoiding overcrowding and wounding during cultivation.
Sanitation is also very important.
It is also helpful to control insects and mites since injuries associated with their activity provide sites for infection. Insect Problems Aphids, Anuraphis tulipae . The tulip aphid, Anuraphis tulipae , is perhaps the most common and most troublesome aphid on tulip, and is more apt to cause injury on forcing bulbs than those grown outdoors. It also winters on stored gladiolus corms. Immersing the infested bulbs or roots in 110 F water for 30 minutes will destroy the insects.