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
Apples
Apricots
Asparagus
Beets
Blueberries
Broccoli
Brussels Sprouts
Cabbage
Carrots
Cauliflower
Cherries
Cucumbers
Dry Beans
Eggplant
Ethnic Vegetables
Garlic
Grapes
Horseradish
Kohlrabi
Leeks
Lettuce / Leafy Greens
Melons
Nectarines
Onions
Parsnips
Peaches
Pears
Peas
Peppers
Plums
Potatoes
Pumpkins / Gourds
Radishes
Raspberries / Blackberries
Rhubarb
Rutabaga
Snap Beans
Squash - Summer
Squash- Winter
Strawberries
Sweet Corn
Sweet Potatoes
Tomatoes
Turnips
Upcoming Events
Rulfs Orchard Vegetable and Berry Field Meeting
August 4, 2026
Peru, NY
Join CCE vegetable specialists Elisabeth Hodgdon and Chuck Bornt for a vegetable and berry field meeting at Rulfs Orchard, in Peru, NY. We'll tour the farm's fields and talk about integrated pest management of sweet corn and cucurbit crops. Then, we'll view a drone demonstration and discuss new technologies for pesticide application and spotted wing drosophila management in berries. Light refreshments will be provided. A rain date will be announced if adverse weather is predicted.
Field Day at Philia Farm
August 6, 2026
Johnstown, NY
Visit organic seed production trials and tour the farm to see small-scale production systems at work, including tarping, cover cropping, and the use of assorted mulches and covers to modify the growing environment.
Capital Region Orchard Twilight Meeting
August 11, 2026
Rexford, NY
Join the ENYCHP and Cornell scientists on August 11 for the Capital Region Orchard Twilight meeting in Saratoga! We will be touring Bowman Orchards and reviewing seasonal recommendations for pests and diseases for apples, plums, and berries, as well discussing crop insurance.
NYSDEC Pesticide Applicator Recertification Credits: 1.25 in categories 22, 1A, & 10. Refreshments will be provided.
Free to attend, however we do ask that you register ahead so we know how many people to expect.