Which cultural practices help reduce powdery mildew on ornamentals in Florida's humidity?

• A. Overhead watering and dense planting.
• B. Improve air circulation, avoid overhead watering, prune for spacing, select resistant varieties, and apply fungicides as needed.
• C. Keep plants in shaded, crowded conditions.
• D. Fed with high-nitrogen fertilizer only.

Answer: (B)

Powdery mildew in humid Florida is best managed by cultural practices that reduce leaf moisture and improve airflow around plants. The fungus thrives when leaves stay wet or when air movement is limited, so opening up the canopy and keeping foliage dry are key. Improve air circulation by spacing plants properly and pruning to create a more open canopy, which lowers humidity buildup around leaves. Avoid overhead watering and use base or drip irrigation to keep leaf surfaces dry, because wet leaves give the mildew spores a place to germinate and spread. Choose resistant varieties when available to lessen susceptibility, and use fungicides as needed as part of an integrated approach, especially during times of high humidity or prolonged wet weather. The other options would worsen the problem by increasing leaf wetness or crowding, which creates the conditions powdery mildew loves, or by relying solely on fertilizer without addressing moisture and airflow.