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 Meeting for Auction Growers (Ontario)

June 27, 2023
Rushville, NY
This on-farm meeting will feature pest management in fresh market vegetables in both field and greenhouse (high tunnel) vegetables, primarily for those growing for wholesale auction. A hands-on demonstration of weed, insect and disease identification in vegetables including management options such as inter-row cover crops, grafting and, where appropriate, spray options will be used to educate growers. Details on each topic will focus on field observations at the farm.
DEC recertification credits will be offered (1.75 credits in categories 10, 1a, 23, 24).
Vegetable Pest and Cultural Management Meeting for Auction Growers (FLPA)

July 12, 2023
Penn Yan, NY
This meeting will feature pest management in fresh market vegetables in both field and greenhouse (high tunnel) vegetables, primarily for those growing for wholesale auction. A hands-on demonstration of weed, insect and disease identification in vegetables including management options such as inter-row cover crops, grafting and, where appropriate, spray options will be used to educate growers.
DEC recertification credits will be offered (1.75 credits in categories 10, 1a, 23, 24).
Vegetable Pest and Cultural Management Meeting for Auction Growers (Seneca)

August 2, 2023
Romulus, NY
This meeting will feature pest management in fresh market vegetables in both field and greenhouse (high tunnel) vegetables, primarily for those growing for wholesale auction. A hands-on demonstration of weed, insect and disease identification in vegetables including management options such as inter-row cover crops, grafting and, where appropriate, spray options will be used to educate growers.
DEC recertification credits will be offered (1.75 credits in categories 10, 1a, 23, 24).