🍄Fungal diseasesModerate
Cedar-Apple Rust
Risk near you, next 48h
See whether your local forecast favours this disease right now.
When it strikes
Temperature
8–24°C
Humidity
≥85%
Leaf wetness
Required
Season
Spring
About
Cedar-apple rust (Gymnosporangium) needs both junipers and apples to complete its life cycle, spotting apple foliage and fruit after wet spring weather when orange spores release from cedar galls.
Symptoms
Bright yellow-orange spots on apple leaves and fruit that develop tube-like structures beneath; on junipers, brown galls produce gelatinous orange horns when wet.
Organic Treatment
Remove nearby juniper galls before spring rains, rake apple leaf litter, and apply sulfur during the infection window.
Chemical Treatment
Myclobutanil applied from pink bud through early fruit development.
Prevention
Separate apples from junipers, plant resistant apple cultivars, and prune galls from cedars in late winter.