Disease: Bipolaris leaf spot

Pathogen: Bipolaris setariae, Bipolaris spp. (fungus)

Hosts: (palm genera) Adonidia, Archontophoenix, Caryota, Chamaedorea, Cocos, Dypsis, Elaeis, Howea, Licuala, Livistona, Phoenix, Pritchardia, Ptychosperma, Ravevea, Rhapis, Roystonea, Syagrus, Washingtonia

Symptoms: Leaf spots begin as tiny, water-soaked spots, which may be chlorotic to greenish brown, expand into circular to elliptical lesions (2-10 mm or more), becoming brown, reddish-brown, or dark-brown to black in color. May be chlorotic halo around lesions. Some palm species will have sunken, “eye spot” symptom. In severe cases, lesions coalesce and fronds become shredded.

Signs: Fungal sporulation on the surface of blighted tissue

IPM: Reduce water splashing; reduce relative humidity in canopy; preventive fungicide applications; clean planting material; reduce excess moisture; reduce duration of leaf wetness; sanitation

Fungicides*: Dithane, Banner Maxx, Chipco 26019, Daconil Ultrex, Heritage,

Back to the Palm Pest and Disease Image Gallery

*Registered for use in Hawaii.

*Named products are not necessarily recommended by the University of Hawaii.

*Always follow the pesticide label instructions.