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
Vegetable Pest and Cultural Management Field Meeting for Auction Growers -- Chautauqua
July 14, 2026
Panama, NY
A field walk will demonstrate pest management in fresh market vegetables in both field and greenhouse (high tunnel) vegetables, primarily for those growing for wholesale auction. CCE Cornell Vegetable Program Specialist Judson Reid will identify weeds, insects and diseases in vegetables and will go over management options such as inter-row cover crops, grafting, and where appropriate, spray options.
DEC recertification credits will be offered.
Vegetable Pest and Cultural Management Field Meeting for Auction Growers -- Allegany
July 15, 2026
Fillmore, NY
A field walk will demonstrate pest management in fresh market vegetables in both field and greenhouse (high tunnel) vegetables, primarily for those growing for wholesale auction. CCE Cornell Vegetable Program Specialist Judson Reid will identify weeds, insects and diseases in vegetables and will go over management options such as inter-row cover crops, grafting, and where appropriate, spray options.
DEC recertification credits will be offered.
Pest Management for Small-Scale Growers
July 23, 2026
Rochester, NY
Join us for a hands-on field day exploring integrated pest management tools for small-scale growing spaces and the opportunity to build community with local growers! Learn the best practices for using row covers, biocontrols, trapping, and more.