Information Bulletin
Date: 14 January 2008
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Out of hours telephone 020 7270 8960
Phytophthora kernoviae found on Vaccinium
Defra has confirmed the first finding in the wild of Phytophthora kernoviae on Bilberry, Vaccinium myrtillus, at a site in Cornwall and is discussing containment and eradication action with local stakeholders.
Phytophthora kernoviae is a fungal infection of plants and trees. It is known to kill trees and there is evidence that it has the potential to kill native heathland species and cause serious disease to certain garden shrubs.
Further investigation is being undertaken to confirm this is an isolated incident.
More information on P. kernoviae can be seen on the Defra website at: www.defra.gov.uk/planth/pests.htm
Further Information
1. Phytophthora kernoviae was first discovered in Cornwall in October 2003 and is thought to have arrived in the GB within the last ten to twenty years. It is only known to exist in England, Wales and New Zealand and recently Scotland. An interdepartmental Programme Board, with representatives from Defra, the Forestry Commission and the Devolved Administrations oversee a programme aimed at containing this disease.
2. P. kernoviae is present at a number of sites in Cornwall and a few in south Wales. By September 2007 there had been three nursery outbreaks of P. kernoviae, one of which has been eradicated, and 46 outbreaks in the wider environment (principally woodland or public gardens), none of which has been found completely clear of infection, although good progress has been made towards eradication at a number of these sites. The first finding of P. kernoviae in Scotland has been confirmed this week, see www.scotland.gov.uk for more information.
3. The pathogen causes bleeding bark cankers on certain tree hosts, especially in the family Fagaceae (e.g. beech and oak); these cankers can girdle and kill affected trees. It also causes leaf blights or dieback on a range of shrub hosts and also some trees; these foliar hosts are responsible for producing inoculum which can infect the stems of susceptible trees. The known hosts of P. kernoviae to date include Fagus sylvatica(beech), Rhododendron spp., Quercus robur (English oak), Quercus ilex (Holm Oak), Gevuina avellana (Chilean hazelnut), Liriodendron tulipfera (tulip tree), Magnolia stellata, Michelia doltsopa and Pieris formosa. In GB, trees with bleeding bark cankers have to date all been in close proximity to infected rhododendron, particularly Rhododendron ponticum.
4. Vaccinium myrtillus (bilberry) is native to heaths, moors and acidic woodlands and forms an integral component of native healthland. It is commonly found throughout the British Isles and can become locally dominant in England towards the southeast. Vaccinium myrtillus was identified as a susceptible species in laboratory experiments by the Central Science Laboratory in 2006.
5. P. kernoviae is quite distinct from Phytophthora ramorum, another fungal pathogen of plants also currently the subject of containment action, but seems to behave in a similar fashion and to pose similar risks.
6. Guidance material for gardeners on how to minimise the risk of introducing Phytophthora ramorum and Phytophthora kernoviae is available on the Defra and Forestry Commission websites at the following links:
www.defra.gov.uk/planth/pestnote/kern.pdf (PDF)
http://www.forestry.gov.uk/forestry/infd-6abl5v
End
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Page published:14 January 2008