Poland and USA (California, Colorado, New York, Utah and Washington)
The exterior of the bulb remains asymptomatic while the inner scales show a brown to black discoloration and decay.
Conditions for Disease Development
This disease was observed in mature bulbs in the field after a period where air temperatures had reached 40-45°C (104-113°F). The bacterium is common in many environments and is considered to be an opportunistic pathogen on onions.
No control measures have been reported.