- Uneven irrigation of onion fields increases the chances of this disorder.
- Fields that are over irrigated, allowed to dry completely and then over irrigated again often have many split bulbs.
- Bulb mites are frequently associated with bulb splitting.
- The first symptom is observed as the rotting of the basal portion of the bulb.
- Secondary growth of the affected bulb often occurs when several small bulbs protruded from the spilt basal portion.