Diagnosis Complete
Marssonina Leaf Blotch (Diplocarpon mali)
Analyzed September 10, 2026
Primary Diagnosis
Marssonina Leaf Blotch (Diplocarpon mali)
Diagnostic note
The leaves display prominent marginal necrosis and large brown blotches typical of late-stage Marssonina leaf blotch or severe apple scab. High humidity and poor airflow aggravate fungal progression, causing rapid expansion of lesions and premature leaf drop.
What the AI detected
- Large reddish-brown necrotic lesions expanding from leaf margins
- Dark brown irregular blotches coalescing across leaf tissue
- Chlorotic yellowing adjacent to necrotic areas
- Severe tissue necrosis leading to leaf deformation
Alternative possibilities
Treatment plan
- 1Rake and destroy fallen leaves to reduce overwintering fungal inoculum
- 2Prune tree canopy to improve airflow and sunlight penetration
- 3Apply preventative copper-based or sulfur fungicides during early spring growth
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.