White Rot and Black Rot Biology and Management
Mike Basedow, Tree Fruit Specialist
Eastern New York Commercial Horticulture
The white rot fungus, Botryosphaeria dothidea, often referred to as "Bot rot" or Botryosphaeria rot, can be a distinct canker on twigs, limbs, and trunks. The fungus produces two types of fruit rot, but leaf infections do not occur. Drought stress and winter injury have been associated with an increase in infection and canker expansion. This is a relatively weak fungal pathogen, and is only problematic when a tree is stressed, such as due to drought, winter injury, insect damage, or fire blight.
The black rot and frogeye leaf spot fungus, Botryosphaeria obtusa, attacks fruit, leaves, and bark of apple trees and other pomaceous plants.
White Rot and Black Rot Biology and Management (pdf; 287KB)
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
Vegetable Field Meetings with Dr. Steve Reiners
July 14, 2025 : Herkimer County - Ivan Martin's Farm
Herkimer, NY
Topics: Tomato Fertility and Mitigating Physiological Disorders; Pest Scouting, ID, and IPM Field Walk.
July 15, 2025 : Washington County - Hand Melon Farm
Greenwich, NY
Topics: Tomato Fertility and Mitigating Physiological Disorders, Tomato and Sweet Corn IPM; FSMA Water Assessments and Postharvest Sanitation
July 16, 2025 : Ulster County - Wallkill View Farm
New Paultz, NY
Topics: Tomato Fertility and Mitigating Physiological Disorders; Veg Pest Update and Management; Cornell Tomato Breeding Program and Slicer Tomato Variety Trial Tour
2025 Berry Twilight Meetings
July 2, 2025 : Berry Twilight Meeting at Dressel Farms
New Paltz, NY
Join Heather Kase, CCE ENYCHP, and Anna Wallis, Cornell IPM, for seasonal updates on berry pest man-agement and IPM.
July 16, 2025 : Berry Twilight Meeting at Samascott Orchards
Kinderhook, NY
Join Heather Kase, CCE ENYCHP, and Anna Wallis, Cornell IPM, for seasonal updates on berry pest man-agement and IPM.
August 6, 2025 : Berry Twilight Meeting at Fishkill Farms
Hopewell Junction, NY
Join Heather Kase, CCE ENYCHP, and Anna Wallis, Cornell IPM, for seasonal updates on berry pest man-agement and IPM.
Champlain Valley Orchard Field Afternoon
July 17, 2025 : Champlain Valley Orchard Field Afternoon
Chazy, NY
This July ENYCHP will be hosting an orchard field afternoon highlighting Mike's research trials at Chazy Orchards.