O-zone Injury on Vegetables
Crystal Stewart-Courtens, Extension Vegetable Specialist
Eastern New York Commercial Horticulture
Common ozone symptoms are small, irregular, shaped spots that range in color from dark brown to black (stipple like) or light tan to white (fleck like). These spots are found only on the upper surface of the leaf. Very young and old leaves are less susceptible to ozone while newly mature leaves are the most susceptible. With severe damage, symptoms may extend to the lower leaf surface.
Insect feeding (red spider mite and some leafhoppers) produce flecks on the upper surface of leaves, much like ozone injury. Flecks from insect feeding are usually spread uniformly over the leaf surface while ozone flecks are concentrated in specific areas, usually most pronounced at the leaf tip and along the margins.
The most sensitive crops include: Bean, Broccoli, Muskmelon, Onion, Potato, Radish, Spinach, Sweet Corn, Tomato
Intermediate crops include: Carrot, Endive, Parsley, Parsnip, Turnip
Tolerant crops include: Beet, Cucumber, Lettuce
Asparagus
Beets
Broccoli
Brussels Sprouts
Cabbage
Carrots
Cauliflower
Cucumbers
Dry Beans
Eggplant
Ethnic Vegetables
Garlic
Horseradish
Kohlrabi
Leeks
Lettuce / Leafy Greens
Melons
Mushrooms
Onions
Parsnips
Peas
Peppers
Potatoes
Pumpkins / Gourds
Radishes
Rhubarb
Rutabaga
Snap Beans
Squash - Summer
Squash- Winter
Sweet Corn
Sweet Potatoes
Tomatoes
Turnips
Upcoming Events
2026 NYS Processing Vegetable Educational Meeting
March 16, 2026
Batavia, NY
Processing vegetable industry members who grow, manage, or support crop production for Farm Fresh First/Nortera Foods, Seneca Foods and/or Love Beets, are encouraged to sign-up for the 2026 NYS Processing Vegetable Industry Meeting! You will:
- Network at this in-person meeting.
- Learn the results of industry-funded research.
- Have a voice in Cornell research and Extension.
DEC recertification credits available: 2.0 in categories 1a, 10, and 23.
2.0 Certified Crop Advisor (CCA) credits available.
Virtual Asparagus School
March 17, 2026
Join us to dive deep on growing asparagus! Bringing together experts from the Cornell Vegetable Program, Michigan State University, OMAFA (Ontario Ministry of Agriculture, Food, and Agribusiness), and industry, featuring a panel of growers.
Postharvest Water Management, Sanitation, and Traceability Workshop
March 18, 2026
Albion, NY
Cornell University personnel from the National GAPs Program and the Produce Safety Alliance are presenting a workshop on postharvest water management, sanitation, and traceability. This workshop will include a mix of short talks and hands-on activities to provide attendees with applied experience with sanitation, postharvest water, and traceability topics.
2.75 NYSDEC CEU's in categories 10, 1a, and 23 available.