Diagnosis Complete
Cercospora Leaf Spot (Cercospora rosicola)
Analyzed September 6, 2026
Primary Diagnosis
Cercospora Leaf Spot (Cercospora rosicola)
Diagnostic note
The distinct purple-to-maroon borders surrounding light gray or tan centers are classic symptoms of Cercospora leaf spot or Spot anthracnose on rose foliage. Unlike typical Black Spot (Diplocarpon rosae), which usually exhibits feathery black margins with surrounding chlorosis, Cercospora and Spot Anthracnose maintain well-defined dark borders with pale necrotic centers that sometimes drop out to form a shot-hole appearance.
What the AI detected
- Numerous circular to sub-circular leaf lesions
- Dark reddish-purple to maroon raised borders around spots
- Light tan to ash-gray necrotic central tissue
- Coalescing spots causing localized marginal necrosis and leaf warping
- Widespread distribution across upper and lower leaf surfaces
Alternative possibilities
Treatment plan
- 1Prune and dispose of heavily infected leaves and fallen debris around the base of the plant to reduce spore load
- 2Avoid overhead irrigation and ensure leaves dry quickly by watering at the soil level in the morning
- 3Improve air circulation through selective pruning of internal canes
Treatment guidance informed by published plant pathology research.
Photo tips for better accuracy
Diffuse natural light
Shade or overcast is best — direct sun creates glare that hides lesion detail.
Frame the affected area
Fill the frame with the sick leaf. More detail = more accurate result.
Plain background
White or neutral surface behind the leaf reduces visual noise.
Multiple angles
If symptoms are subtle, try 2–3 shots from slightly different angles.