What are typical symptoms of powdery mildews?

• A. White, powdery-looking fungal colonies on leaf surfaces and stems
• B. Dark brown spots with concentric rings
• C. Mottling with yellow chlorosis only
• D. Root rot and wilting

Answer: (A)

Powdery mildews are identified by a white, powdery coating that covers leaf surfaces and often stems. This dusty growth is a superficial fungal colony, so you see a chalky white layer rather than dark spots or tissue collapse. On many plants the white layer starts on new growth or the upper leaf surface and can lead to curling, distortion, and reduced photosynthesis as leaves become less effective at capturing light. This symptom set is distinct from other issues: dark brown spots with rings are typical of certain leaf-spot diseases, mottling with yellow chlorosis points to nutrient problems or viruses, and root rot with wilting reflects problems below the soil. So the white, powdery appearance on leaves and stems accurately reflects powdery mildew infection.