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
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March 10, 2026 : New Farm Manager Skills Day - Get the Tools You Need to Grow Your People
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Are you moving into a supervisory farm management role this season and want to get off to a good start? Are you an experienced manager who wants to connect with other "people" managers and work on your skills? This one-day workshop is for you!
SPARC WSU Tree Fruit Heat School
March 11, 2026
As part of our multi-state SPARC SCRI project on mitigating orchard heat and cold stress, the WSU Tree Fruit Heat School will focus on understanding and managing heat-related challenges in apple and pear production. The program brings together research-based insights and applied discussions on sunburn physiology and mitigation, red color development in apples and pears, and the impacts of heat on postharvest storage and fruit quality. Each session will include an expert presentation, followed by a panel discussion with panelists from across the US.