Concern about the poor health of oak trees in Auckland was raised in 2001. An intensive investigation of oak trees showing symptoms of decline (twig and branch dieback, epicormic growth, trunk cankers, bark loss and tree death) was conducted in the Auckland area during 2006. Disease symptoms on trees at 13 sites were documented and samples of leaves, stems, trunks, roots and soil collected. Soil samples were tested for the presence of soil-borne fungi using baiting techniques. Fungi and bacteria fromplant tissues and soil were identified using either morphological characteristics, biochemical testing or molecular techniques. The investigation resulted in a range of fungi and bacteria being identified. One fungus new to New Zealand was detected andseveral new host associations observed. No particular organism was implicated as the cause of the oak decline, but several fungi and bacteria were likely contributors to the tree decline and death in Auckland.
展开▼
