Phytophthora ramorum (cause of Sudden Oak Death in the USA)
Phytophthora ramorum is a serious fungal pathogen causing damage to trees and a range of ornamental and native plants in the USA and in many countries in Europe including the UK. The disease is known to infect a number of other tree species and woody shrubs, especially rhododendron spp and viburnum which are still regarded as the main hosts. The pathogen was detected in plants moving in trade for the first time in the UK in April 2002 and in Scotland in May 2002.
As of September 2008, P. ramorum has now been found at 43 sites in Scotland and at several hundred sites in England and Wales and a number of sites in Northern Ireland and the Channel Isles. This total includes some outbreaks on established plants in parks, gardens or wild areas.
Full details of this pathogen can be found in the Information Sheet in the relevant Plant Health pages of Defra's web site.
Phytophthora kernoviae
Another new Phytophthora species, P. kernoviae, was discovered at a number of P. ramorum sites in southern England in 2003. It has also now been found at other locations in SW England, in Cheshire and in Wales. Two of the sites in SW England have been set up by the Forestry Commission and Defra as research sites to investigate the epidemiology of the disease. P. kernoviae was found for the first time in Scotland in January 2008.
Further information about P kernoviae may be found in the relevant Plant Health pages of Defra's web site.
A map showing outbreaks of both species in gardens and the wider environment in Scotland is now available.