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

Upcoming Events
2026 NYS Dry Bean Meeting and Cutting Event
March 20, 2026
Geneva, NY
The Cutting Event will be held in the morning, followed by lunch, and the NYS Dry Bean Meeting in the afternoon.
DEC recertification credits available for the NYS Dry Bean Meeting portion of the day: 2.0 in categories 1a, 10, 21, and 23.
Harmonized GAP Plus+ Plan Writing Session
March 20, 2026
Newark, NY
Join us for this specialized workshop to cover requirements for this specific audit. Commercial fruit and vegetable growers are increasingly being asked to have the Harmonized GAP Plus+ audit to satisfy some large buyer's requirements.
2026 Rochester Urban Agriculture Conference
March 21, 2026
Rochester, NY
Join us for our annual Rochester Urban Agriculture Conference, a day of learning and connections featuring interactive workshops, community knowledge sharing, Fruition's Gift of Seed Experience, horticulture tables and displays, and more!