Botryosphaeria Leaf Blight of Palms

Symptoms

Brown-to-black necrotic lesions on fronds, often starting at the tips or margins, with dieback of affected frond sections in humid conditions.

Cause & development

Palm foliage has been documented as a pathway for pathogenic Botryosphaeriaceae fungi including Lasiodiplodia species (Chi et al., "Palm Foliage as Pathways of Pathogenic Botryosphaeriaceae Fungi and Host of New Lasiodiplodia Species from Mexico," Pathogens, 2021, PMID 34684246). Most relevant to Areca Palm and Parlor Palm, though more commonly documented on outdoor/landscape palms than small potted specimens. EPPO code PHYORH.

Favorable conditions

• •Warm, humid conditions
• •Plant stress from underwatering, poor light, or root problems
• •Wounds or damaged frond tips

Management

1. 1Remove and discard affected fronds
2. 2Improve growing conditions to reduce plant stress
3. 3Improve air circulation around the plant