Phytophthora cambivora added again to the EPPO Alert List
As reported in EPPO RS 2000/048, the EPPO Panel on Phytosanitary Measures decided at its last meeting in January 2000 to remove Phytophthora cambivora (on alder) from the EPPO Alert List. It was felt that this pathogen of alder was essentially causing problems for the environment and could not really be handled by plant quarantine. However, Dr Gibbs from the Forestry Commission of UK has stressed that despite a fair amount of searching in several European countries, the pathogen has only been found in Austria, France, Germany, Netherlands, Sweden and UK. There are no records of this disease in other EPPO countries and alder is a common and important tree in Europe. There is also some evidence to suggest that this pathogen is a new organism, related to P. cambivora but distinct from it. Finally, the pest can be disseminated in the EPPO region through the movement of nursery plants. It has accordingly been decided to reinstate P. cambivora in the EPPO Alert List. It is recalled that the EPPO Alert List is maintained on the EPPO web site (www.eppo.org).
Phytophthora cambivora (a new root disease of alder)
Why: This came to our attention because a new root disease of alder causing tree mortality was first reported in UK in 1993.
Where: UK, and then in the Netherlands. According to the UK Forestry Commission, the fungus has also been found in Austria, Denmark, France, Germany, Sweden (UK Forestry Commission Web site).
On which plants: Common alder (Alnus glutinosa).
Damage: Dead roots, leaf fall, dieback, presence of tarry or rusty spots on the stem base of trees. Tree mortality has been observed. In 1994, it was reported that more than 20,000 alders were affected in southern Britain (UK).
Possible identity: An unusual form of Phytophthora cambivora.
Pathway: Alder plants for planting and wood(?) from infested countries.
Possible risks: Alders are important trees in the landscape. Tree mortality is reported. Further work is needed on the identity of the pathogen and possible means of control.
EPPO RS 95/010, 96/041, 98/023, 99/084, 99/156, 2000/083
Panel review date 1999-01 Entry date 1995-01
Annual Report 1996, Diagnostic Centre, Plant Protection Service, Wageningen, Netherlands, 114 pp.
Brasier, C.M.; Rose, J.; Gibbs, J.N. (1995) An unusual Phytophthora associated with widespread alder mortality in Britain. Plant Pathology, 44(6), 999-1007.
Gibbs, J. (1994) Phytophthora root disease of common alder. Research information Note 258. Forestry Authority, Forestry Commission, Wrecclesham, Farnham, Surrey, GB, 4p.
Gibbs, J.N.; Lipscombe, M.A.; Peace, A.J. (1999) The impact of Phytophthora disease on riparian populations of common alder (Alnus glutinosa) in Southern Britain. European Journal of Forestry, 29(1), 1-88.
Streito, J-C.; de Villartay, G.; Tabary, F. (1999) Une nouvelle espèce de Phytophthora s'attaque à l'aulne. Phytoma - La Défense des Végétaux, no. 519, 38-41.
Web site of the UK Forestry Commission - http://www.forestry.gov.uk/research/summary.html
Web site of the Laboratoire National de la Protection des Végétaux, Nancy (FR) Le Phytophthora de l'aulne. http://perso.wanadoo.fr/lnpv/nancy/aldphyt.htm
Personal communication with Dr J.N. Gibbs, Forestry Commission, UK, 2000-03.