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
Fungi, Forage & Forest
June 12, 2026 : Friday Evening
Buckets, Beds & Totems
Explore mushroom cultivation techniques featuring oyster mushrooms, wine caps, and lion's mane mushrooms.
June 13, 2026 : Saturday Full-Day
Wild Edibles
Learn about edible plants and responsible foraging practices focused on plants only (no wild mushroom foraging).
Agroforestry Talk
Discover how agroforestry systems can support farm diversification and sustainable land management.
Shiitake Inoculation (hands-on workshop at Heartland Organics)
Participate in a hands-on shiitake inoculation workshop and learn the basics of log-grown mushroom production.
2026 Muck Onion Growers Twilight Meeting in Oswego
June 18, 2026
Oswego, NY
Open to all Onion Enthusiasts, the Muck Onion Growers Twilight Meeting will include an onion disease research update from 2025, new fungicide recommendations for 2026, an onion maggot seed treatment update, herbicide demonstration tour, and more. This educational event is immediately followed by a catered dinner; both are FREE thanks to generous sponsors!
2.25 DEC recertification credits available in categories 1a, 10 and 23. CCA credits will be offered too.