Phalaenopsis Leaf Spot: Sun Focus + Fungal Entry

Diagnosing a Discolored Leaf with a Black Spot

A single Phalaenopsis leaf with an eroded, black-spotted area among healthy neighbors suggests localized damage.

Likely Sequence

1. Sunlight focused through water droplet or glass → tissue erosion.
2. Damaged area → entry point for fungus.
3. Fungal activity → chlorophyll loss (yellowing) around spot.

Treatment

• Cut leaf 1 inch below yellowing.
• Seal cut with powdered sulfur, Rootone, or fungicide.
• Review light exposure—avoid water on leaves in bright sun.

Isolate the plant briefly. Monitor others—this appears isolated, not systemic.