Pink root rot
Crop: Onion Disease: Fungal Pathogen: Phoma terrestris (syn. Pyrenochaeta terrestris)
SYMPTOMS AND SIGNS
DISEASE DEVELOPMENT
DISEASE MANAGEMENT
- Onion roots develop pink color. May occur in seedling stage or mature onion. Older infected root turn dark and die.
- Infected roots show a light pink color that become deeper pink or red with time and finally purple-brown as the roots shrivel and disintegrate. New roots may continue to form and then be killed by the fungus.
- Reduced bulb size. Roots turn pink or maroon when infected. Leaf number and size are reduced and the plants are easily uprooted.
- Roots turn pink or maroon when infected. Leaf number and size are reduced and the plants are easily uprooted. Reduced bulb size.
- In severe cases the roots may die and the plants become weakened or stunted, especially in drier areas of the field. Bulbs lack normal development, reduced in size and vigor and have stunted tops.
- The disease may appear either in young seedlings or later in the onion's growth. Infected roots turn yellow, then pinkish, then bright pink to red and finally to dark purple as they dry and disintegrate. New roots produced thereafter become diseased and also die.