What to observe

• White powdery colonies that recur or expand rather than wiping away permanently
• Distribution on leaves, petioles, stems, or flowers depending on disease stage
• New colonies appearing over time
• Microclimates with limited air movement or favorable humidity patterns

Common look-alikes

• Mineral or spray residue
• Dust
• Dried droplets
• Other superficial fungal growth

Evidence that improves confirmation

• Inspect colony structure with magnification
• Compare wiped and unwiped areas over time
• Use microscopy or laboratory testing when species-level or regulatory confirmation matters

Risk context

• Dense canopies and susceptible cultivars can increase risk
• Air movement within the canopy and moisture management affect disease conditions
• Infected plant material can serve as inoculum

Management principles

• Separate or remove heavily affected material according to site policy
• Improve sanitation and environmental management
• Reduce movement of contaminated plant debris
• Use only lawful, crop-appropriate disease controls and verify new-colony incidence

Keep the conclusion proportional to the evidence

Use a confirmed identification when available. When evidence is incomplete, label the conclusion as a suspicion or differential rather than presenting it as proven.

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