13 Mar Ash Dieback Disease
Background to Ash Dieback Disease
Chalara fraxinea, known as ash dieback disease, is a relatively newly described fungal disease of ash which was first named in 2006 although dieback symptoms in ash had been first noted in Poland in the early 1990s. The harmful reproducing stage of the fungus, a new species Hymenoscyphus pseudoalbidus, was later discovered in 2010. The disease has spread rapidly across much of Europe, with the majority of European countries where ash is present now reporting the disease.
Common ash (Fraxinus excelsior) is susceptible to Chalara dieback, as are a number of other species of ash. The disease can affect ash trees of any age and in any setting. Death of the trees can occur, with younger trees (less than 10 years old) succumbing more rapidly.
It is likely that plants for planting that are imported from other European countries are the highest risk pathway for spread into Ireland. Wood, including firewood, is also likely to be a pathway.
The wide range of symptoms associated with Chalara includes:
- Necrotic lesions and cankers along the bark of branches or main stem
- Foliage wilt
- Foliage discolouration (brown / black discolouration at the base and midrib of leaves)
- Dieback of shoots, twigs or main stem resulting in crown dieback
- Epicormic branching or excessive side shoots along the main stem
- Brown / orange discolouration of bark
(Note: The symptoms described above are not exclusive to Chalara fraxinea and may be attributable to a number of other causal agents or factors, e.g. frost.)
Ecoplan Forestry specialise in the management and control of Chalara, for more information Contact Ecoplan Forestry