Occurrence of Alternaria Leaf Spot in Ming Aralia and Geraniumleaf Aralia Caused by Alternaria panax on Ogasawara (Bonin) Islands

Abstract

Leaf spot of ming aralia, Polyscias fruticosa (L.) Harms and geraniumleaf aralia, P. guilfoylei (Bull) L. H. Bailey occurred on Ogasawara (Bonin) Islands in 2002. The pathogens isolated from the diseased plants were identified as Alternaria panax Whetzel. An inoculation test confirmed that this fungus was the causal agent of the disease. This is the first report of this disease in Japan.