First report of Phytophthora ramorum on Fagus sylvatica in the Netherlands
In the Netherlands, the presence of Phytophthora ramorum (EPPO Alert List) on Fagus sylvatica (beech) is reported for the first time. In June 2006, during routine surveillance, P. ramorum was identified (by morphology and real-time PCR) in samples taken from bleeding cankers on 2 F. sylvatica trees. These findings were done at 2 locations (public parks) where outbreaks of P. ramorum had previously been found on Rhododendron plants growing under the trees. At one location, the infected parts of Rhododendron plants had been removed and destroyed in the preceding years. In addition, at the same location, 8 infested Quercus rubra (Northern red oaks) had been found (see EPPO RS 2004/024). Further inspections will take place to determine the extent of this outbreak. However, it is presumed that P. ramorum is not capable of sporulating on beech trees, and therefore these infested trees are not considered as presenting a major risk to nearby hosts of P. ramorum. At one location, the infected F. sylvatica tree will be removed as it threatens a house, but at the other location the infected tree will be left for further observations.
The pest status of Phytophthora ramorum in the Netherlands is officially declared as: Present, subject to official control, only in public parks (Rhododendron, Quercus rubra, Fagus sylvatica).
NPPO of the Netherlands, 2006-06.