Cause Several different fungi have been found associated with rotted bulbs by the OSU Plant Clinic. The genus is described as having fragile bulbs that need to be handled carefully. Wounds are common entry points for bulb rotting fungi in other hosts. Different species are found in a wide variety of habitats from very dry to wet environments. Many species need dry conditions when dormant and/or during various periods in their development. Large bulbs develop a hole or hollow area in the center where the plant grew out then died back. This area can retain water which can lead to bulb rots.
Symptoms Bulbs become rotted and decayed.
Cultural control In general, these plants need dry winters and summers but a moist spring.
- Handle bulbs careful to avoid wounds.
- Plant large bulbs on their side to prevent water accumulation in the center.
- Plant in well-drained sites or media.
Chemical control Preventive chemical soaks or drenches are commonly used to limit the damage caused by root rot pathogens.
- Apron XL at 0.085 to 0.64 fl oz/100 lb "seed". Will control Pythium, but not Rhizoctonia. Group 4 fungicide.
Biological control Use in conjunction with other control tactics such as thorough sanitation.
- Actinovate AG (Streptomyces lydicus strain WYEC 108) at 3 to 12 oz/A. 4-hr reentry. O
Reference Brickell, C., and Zuk, J.D. 1996. The American Horticultural Society A-Z Encyclopedia of Garden Plants. DK Publishing, Inc. New York.