Incidence of 'crown fracture' disease of oil palm in Ghana

Abstract

An investigation into outbreak of a ‘strange oil palm disease’ at three locations in the Central and Western regions of Ghana showed the presence of ‘crown fracture’ disease in the country. Thirty-two cases of the disease were identified in Papagya (near Abakrampa), seven in Dwaboh (near Ayensudu), and six in the farm of the St. John’s School, Sekondi. The symptom expression comprised the bending of the inner core of the middle crown at the base just above the growing point, at various angles to the vertical. The fronds of the bent crown core, and those immediately after it died with time, and fruit production ceased. Developing fruit bunches rotted and were covered with thick white mat of Marasmius mycelia. The broken crown always rotted away and in some cases a new inner core of fronds grew out to replace  the rotted one. However, the regenerated inner crown core was always stunted and showed a compacted appearance with much corrugated leaflets. Fruit production was resumed after regeneration of the middle crown. Six of the seven palms at the Dwaboh farm recovered completely, whereas only six of the 32 cases at the Papagya farm and only one out of the six cases at the St. John’s School farm recovered. Affected palms recovered faster when the broken crown was removed by cutting just above the broken point. The crown fracture disease, hitherto unknown in the country, seems to be slowly gaining prominence. The possible causes and significance of the disease are reviewed.