Tomato Foliar White Spots / Mildew

Tomato (Solanum lycopersicum) ยท White Spots & Powdery Film

Chalky residue, powdery patches, or small bleached flecks on leaf surfaces.

Usually powdery mildew or microscopic spider mite stippling where chlorophyll is depleted in microscopic clusters.

Possible causes

  • Powdery mildew fungal colony (Leveillula taurica)
  • Two-spotted spider mite cell feeding under leaf blades
  • Sunscald or cold water droplet lens effect under strong sun

Care steps

  1. Inspect undersides with a 10x lens: Check for fine webbing or crawling pinpoint mites vs powdery fungus.
  2. Isolate & prune infected leaflets: Carefully clip the most heavily spotted foliage into a bag to prevent drift.
  3. Spray potassium bicarbonate or neem spray: Apply at dusk so sunlight does not scorch wet leaves.

Prevention tips

  • Never mist tomato leaves in late afternoon or evening
  • Provide full air exchange in enclosed greenhouses or balconies
  • Plant resistant cultivars with enhanced mildew tolerance

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