Powdery Spots on Leaves

Powdery Mildew

Scientific Name: Oidium caricae

Disease Type: Fungus

Plants Affected: 

Papaya, cucumber, cucurbits, mango, mock orange, plumeria, poinsettia, rose, tomato

Symptom:

• Water-soaked spots and powdery patches on underside of leaves
• Powdery spots on immature fruit, which turn into gray scars and deformed fruit shape

Control:

• Manage humidity levels (i.e. Plant in low-rainfall areas, improve aeration between plants)
• Remove and destroy heavily mildewed leaves from site
• Foliar application of fungicide or sulfur

Additional Resources:

• Powdery Mildew of Garden Vegetables in Hawai‘i by Scot Nelson
• Major Papaya Diseases in Hawai‘i by Sabina F. Swift, Lynne N. Constantinides, John J. McHugh, Jr.
• Powdery Mildew of Papaya in Hawai‘i by Brennen Cunningham and Scot Nelson

"Papaya Powdery Mildew" by Scot Nelson is licensed under CC BY-NC-CA 2.0

"Papaya Powdery Mildew" by Scot Nelson is licensed under CC BY-NC-CA 2.0

"Papaya Powdery Mildew" by Scot Nelson is licensed under CC BY-NC-CA 2.0