First report of wilt disease in Dalbergia tonkinensis caused by Ceratocystis manginecans

Dalbergia tonkinensis is a rare and valuable rosewood which is being domesticated in home gardens in north Vietnam. Concern for the viability of this new industry has arisen with growers reporting the recent death of trees. This study identified a new wilt disease causing large bole cankers, associated blue staining to the wood, wilted canopies and tree death in home gardens and plantations. From βT1a and βT1b sequence analysis, the Ceratocystis isolates causing wilt disease in D. tonkinensis belong to Ceratocystis manginecans and were shown to be pathogenic with D. tonkinensis seedlings in a nursery trial. They were also able to form stem cankers in Acacia and Eucalyptus. Cankers in 2–11 year-old trees were associated with wounding, primarily from pruning of branches to improve tree form and drilling of trunks in older trees to assess heartwood formation. To mitigate against further damage, it is recommended that pruning be restricted to the dry season and that the practice of drilling trunks be kept to a minimum.

DOI: 10.1007/s13313-019-00643-1