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
Eden Area Winter Vegetable Meeting
February 4, 2026
North Collins, NY
Join us for a mix of industry updates, crop protection talks, pesticide safety programming, and fertility management discussions. This meeting is jointly hosted by the Cornell Vegetable Program and Timac Laing-Gro.
1.25 DEC credits available in CORE plus 1.75 in 1a and 23.
Orleans Regional Winter Vegetable Meeting
February 9, 2026
Albion, NY
Topics include: Breeding and evaluating tomatoes to control disease and improve yield, jar testing and ensuring spray water quality, breaking down organic matter, FSMA updates and Q&A with Ag & Markets, and industry updates. Includes hands-on learning, coffee break, and sponsor booths.
DEC credits available: 1.0 in CORE plus 0.5 in 1a, 10 or 23
African Eggplant Participatory Breeding Kick-Off
March 5, 2026
Join us to learn about the Cornell African Eggplant Research Project and learn how you can participate! African eggplant, also known as Bitterball, Garden Egg, Kittley and other names, is an important crop for many members of our community with heritage from regions such as sub-Saharan Africa, Southeast Asia, and Brazil. Since 2024, the Cornell African Eggplant Research Project has been collaborating with growers and community partners across New York to develop high-quality varieties adapted to the Northeast U.S. In this meeting, we will share information about growing and preparing African eggplant, highlight our research to date, and invite partners to collaborate with us in our 2026 participatory breeding and variety selection efforts.
COST: FREE! Register online to receive the Zoom link. The Zoom link will be emailed to all registered participants the day before the event.