Vascular Streak Dieback of Cocoa

Abstract

Vascular streak dieback of cocoa caused by Oncobasidium the obromae is a serious disease of seedling and mature cocoa trees in Malaysia, Thailand, Indonesia, Republic of China and Papua New Guinea. The fungus causing the disease was anmed in 1971, with the disease being broken into six categories based on its symptoms. Under natural conditions sporulation takes place at night with infection also taking place at night under conditions of high humidity. The fungus has not been found to sporulate on an artificial media. The disease was first reported in Thailand in 1983 at the Chumphorn Horticulture Research Center in Southern Thailand. Chemical control of the disease has been demonstrated to be possible; research on identifying a cocoa variety resistant to the diseased is continuing.