• Worldwide distribution. On coconuts, date palms, ornamental palms. A minor fungal disease. Unlikely to affect yield of coconuts or date palms; however, possibly a 'cosmetic' disease on palms grown for landscaping, or a problem in the nursery.
• It is not a smut disease. Small, grey or black pustules, 1.5 mm diameter, emerge through the leaf, mainly on the top surface. Spores and sterile threads emerge from the pustules.  
• Spread by spores in wind and rain.
• Cultural control: avoid over-crowding in coconut nurseries. Ideally, grow coconuts in polythene bags and space them at least 1 m apart; not economic to attempt to control the disease in the field - no evidence that it effects yield.
• Chemical control: if fungicides are required in the nursery, use copper products or mancozeb as protectants, or thiophanate methyl (sometimes formulated with chlorothalonil) as a systemic product.

Coconut false rust, coconut leaf smut

Graphiola cocoina. Another species, Graphiola phoenicis is also present in the Pacific islands, in Fiji and Samoa.