Video: How to Diagnose Onion Bacterial Bulb Rot

Bulb rot caused by bacterial pathogens can be confused with bulb rots caused by fungal pathogens as well as physiological disorders. It is important to accurately diagnose the cause of bulb rot/internal disorder in order to determine future effective preventative management strategies. In this simple 4 minute video, accurate identification of bulb rot caused by bacterial pathogens is distinguished from look-alikes caused by fungal pathogens Botrytis neck rot, Fusarium basal rot, black mold and blue mold and physiological disorders dry scale and translucent scale. It was produced by the CCE Cornell Vegetable Program for the Stop the Rot USDA-NIFA Project 2019-51181-30013. Available in both English and Spanish on the CCE Cornell Vegetable Program YouTube channel.
Video Transcript: How to Diagnose Bacterial Bulb Rot (pdf; 393KB)

Upcoming Events
Small Vegetable Workshop
August 13, 2026
Fulton, NY
Identify vegetables that make sense to grow on small acreage, including under high and low tunnel season extension. Bill Ingersoll, owner of Ingersoll Farms, will provide a short tour and discuss other important factors of running a mixed vegetable farm, including a farm stand and selling at farmers' markets.
Chipping Potato and Field Crops Twilight Meeting
August 27, 2026
Dansville, NY
This year, our field meeting is bringing together field crops and chipping potatoes. SWNY Dairy, Livestock, and Field Crops Specialist Katelyn Miller will lead a field crops management discussion. Hear the latest updates in potato disease control and see the Cornell chipping potato variety trial run by Walter De Jong. Dinner follows the educational event.
1.5 DEC credits available in 10, 1a, 21, and 23.
IPM Field Day for Urban Growers
September 10, 2026
Buffalo, NY
Join us for a hands-on field day exploring integrated pest management and season extension tools for urban growing spaces and the opportunity to build community with local growers!
This event will focus on best practices for using row covers and rat mitigation. Check out our CCE demonstration trial using insect exclusion netting to manage swede midge, an invasive fly that causes damage to brassica crops. Explore how to identify rat activity, reduce attractants, and strengthen site management. Hear from local growers on how they manage pests with a focus on organic management and how they extend the season on their farms and gardens.