Overview
The most economically important disease of apples worldwide. The fungus overwinters in fallen leaf litter and releases spores during spring rains. Severe infections reduce fruit quality and yield and can defoliate trees by mid-summer.
- Type
- Fungus
- Severity
- MODERATE
- Source
- USFS
Symptoms
Olive-green to brown velvety spots on leaves, dark scabby lesions on fruit surface, leaf yellowing and premature drop, cracked and deformed fruit in severe infections
Affected Species
Geographic Spread
Treatments
Fungicide Spray Program
Captan or myclobutanil applied from green tip through second cover, with timing adjusted based on rain events and Mills table infection periods. The primary commercial control method.
Sanitation and Resistant Cultivars
Removal or chopping of fallen leaf litter in autumn to reduce spring inoculum, combined with planting scab-resistant cultivars like 'Liberty', 'Enterprise', or 'Pristine'.
Recommended Products & Tools
Helpful supplies for managing Apple Scab. Always read and follow label directions, and confirm a diagnosis before treating.
Broad-spectrum protectant for many fungal leaf and bark diseases.
Preventive spray for needle cast, leaf spots, and blights.
Sharp, clean cuts to remove affected wood — a tree-care essential.
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Frequently Asked Questions
What is Apple Scab?
The most economically important disease of apples worldwide. The fungus overwinters in fallen leaf litter and releases spores during spring rains. Severe infections reduce fruit quality and yield and can defoliate trees by mid-summer.
What are the symptoms of Apple Scab?
Olive-green to brown velvety spots on leaves, dark scabby lesions on fruit surface, leaf yellowing and premature drop, cracked and deformed fruit in severe infections
Where is Apple Scab currently found?
Apple Scab is currently active in California, Connecticut, Iowa, Illinois, Indiana, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, North Carolina, New Hampshire, New Jersey, New York, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Virginia, Vermont, Washington, Wisconsin, West Virginia. It has been reported in 26 total states across the United States.
What plants are affected by Apple Scab?
Apple Scab affects Pear, Apple. Susceptibility varies by species.
How do I treat Apple Scab?
Treatment options for Apple Scab include: Fungicide Spray Program, Sanitation and Resistant Cultivars. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.
Compare with Similar Ailments
Not sure if it's Apple Scab? Compare it side-by-side with similar ailments.