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
Asparagus
Beets
Broccoli
Brussels Sprouts
Cabbage
Carrots
Cauliflower
Cucumbers
Dry Beans
Eggplant
Ethnic Vegetables
Garlic
Horseradish
Kohlrabi
Leeks
Lettuce / Leafy Greens
Melons
Mushrooms
Onions
Parsnips
Peas
Peppers
Potatoes
Pumpkins / Gourds
Radishes
Rhubarb
Rutabaga
Snap Beans
Squash - Summer
Squash- Winter
Sweet Corn
Sweet Potatoes
Tomatoes
Turnips
Upcoming Events
Lake Erie Region Summer Meeting
July 24, 2025
Brant, NY
This meeting will cover organic and conventional management and will be relevant for producers of all sizes. This broad-reaching meeting will feature a mixed fresh market field walk, potatoes, sprayer calibration, and disease control in table and wine grapes. We'll cover organic and conventional controls and present information for growers of all scales of production.
2.0 DEC (0.5 CORE, 1.0 Veg, 0.5 Fruit)
Vegetable Pest and Cultural Management Field Meeting for Auction Growers -- Seneca Produce Auction
July 30, 2025
Romulus, NY
This evening meeting will demonstrate 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. Details on each topic will focus on field observations at the farm.
2.0 DEC credits in categories 10, 1a, 23, and 24.
Niagara Region Summer Meeting, 2025
August 7, 2025
Ransomville, NY
We're in for a treat! Professor Steve Reiners is coming as a part of his pre-retirement speaking tour! Steve's a fantastic, down-to-earth speaker with extensive knowledge on horticultural techniques, fertility, varieties, and much more. Don't miss this event! Topics include "what exactly do NPK and other nutrients do inside the plants?", a pest/disease field walk, sweet corn variety trial, a tar spot primer, spraying best practices, and industry updates. Content will be relevant for organic, CNG, and conventional growers.
DEC credits requested.