Press releases issued by DAFM and DARD: New Detections of Phytophthora ramorum

Press release issued by Department of Agriculture, Food and the Marine on the 31st of March 2011.

Update on Phytophthora ramorum Monitoring

The Department of Agriculture, Food and the Marine is continuing to survey forests and control outbreaks of the EU regulated plant disease Phytophthora ramorum, a fungus like organism that can damage and kill infected trees and plants. Under EU requirements, annual forest surveys for Phytophthora ramorum have been ongoing since 2003. Until last year, there had been no findings on tree species and P. ramorum had only been detected in forest areas on wild invasive rhododendron shrubs.  Following the initial findings in Japanese larch in Ireland in July 2010, an extensive national aerial and ground survey was conducted.  These forest surveys have now confirmed the disease in Japanese larch at eleven forest locations in five counties.

Japanese larch appears to be particularly susceptible to the disease, affecting all age classes and locally causing significant dieback and deaths.  Noble fir, beech and Spanish chestnut growing in close proximity to the infected Japanese larch have also been found to be infected at a number of the sites and it is likely that the Japanese larch is the source of the infection. The infected trees are being removed to prevent the disease spreading.

There has also been a recent scientifically confirmed finding of P. ramorum in a single Sitka spruce tree. The infected young tree is approximately two metres in height and significantly it was growing in close proximity and underneath the canopy of a large infected rhododendron bush. It is very likely that disease spores produced by this overhanging infected rhododendron bush were the source of infection of the tree.  This is the first field record worldwide of P. ramorum infection in Sitka spruce although the species had been found to be susceptible in international laboratory trials. Spruce in the immediate area of all the Japanese larch outbreak sites have been surveyed and no further P. ramorum infections have been found.  The area around the infected Sitka spruce has been effectively quarantined and monitoring will continue.

There has also been significant number of outbreaks of the disease particularly in Japanese larch in Northern Ireland and Great Britain and the Department is liaising closely with the relevant authorities.

The Department continues to take all necessary measures to establish the extent of the infection and to control the spread of the disease.  Forest owners are requested to be particularly vigilant and as the summer growing season commences to report any unusual symptoms of ill health in larch or other species to the Forest Service of the Department.  For further information on the disease please see www.agriculture.gov.ie/forestservice or email forestprotection@agriculture.gov.ie

Note for Editors

1. In the mid-1990s, it was reported that significant numbers of trees and other plant species were being damaged or killed in California and other parts of the western United States by a newly described disease, caused by a new species of fungus like organism named Phytophthora ramorum. The common name for the disease, Sudden Oak Death, which was first assigned in the USA, is a misnomer in a European context as to date European oak species have not been seriously damaged. The same organism had also been found in many European countries including Ireland, on the shrub species Rhododendron and Viburnum spp.
2. Scientific evidence indicates that Japanese larch can produce P. ramorum infection spores at a higher rate than rhododendron and that the disease can be dispersed by the movement of plants and plant products and by the movement of contaminated soil. The disease can also be dispersed by rain, mists and air currents.
3. Legislation was introduced in 2002 under Commission Decision 2002/757/EC on provisional emergency phytosanitary measures to prevent the introduction into and the spread within the Community of Phytophthora ramorum (as amended). The Department under the legislation is therefore requiring felling of all infected trees with a view to minimising the spread of the disease.
4. The felling associated with the 11 confirmed Japanese larch outbreak sites amounts to approximately 125 ha of forest.  Most of the wood from infected trees can be utilised and sold in the normal way when the necessary prescribed hygiene measures are taken during felling, transport and processing in approved sawmills and other wood processing facilities.

Press release issued by the Department of Agriculture and Rural Development, Northern Ireland on 1 April 2011.

Ramorum disease, which has caused the early felling of Japanese larch trees in both the north and south of Ireland, has now been detected on two additional trees species.

As part of ongoing North – South liaison meetings to address Ramorum disease, caused by the fungus- like organism Phytophthora ramorum, DARD Officials have been informed of confirmation of the disease in a single young Sitka spruce tree in the south of Ireland. This tree was found in close proximity to, and underneath the canopy of a large infected rhododendron bush. This is the first field record worldwide of P.ramorum infection in Sitka spruce, although the species had been found to be susceptible in international laboratory trials.

In another recent development, the Forestry Commission’s research agency in Britain has confirmed P.ramorum infection in European larch. The finding was in a woodland in the south west of England in an area with infected Japanese larch trees nearby. Again, this is the first recorded finding on this species of larch.

Responding to the news of these developments, a DARD spokesperson commented “While the finding in Sitka spruce must be taken in the context of a single tree underneath the canopy of an infected rhododendron, it is still a cause for concern. Sitka spruce is a commercially important tree species and accounts for some two thirds of the public forest estate here.

DARD also confirmed diagnosis of the disease on a small number of beech trees in Co Down. Beech has been diagnosed in the past at a number of locations in Britain and Ireland.

The spokesperson went on to add “We are responding to these developments by adapting our planned surveillance to take in Sitka spruce in areas where Japanese larch and Rhododendron have been infected and to widen our surveys of Japanese larch to include all larch species. We continue to liaise closely with our colleagues in the south of Ireland and in Britain on these developments. In relation to the new local site, DARD Inspectors are working closely with the landowner in relation to appropriate biosecurity measures”.

“Additionally, the Minister has been made aware of these developments and is monitoring them closely and the Department will consider next week what additional measures may be taken.”

DARD is continuing to take appropriate action to control P.ramorum infection. As we now enter a new growing season, woodland owners and managers are asked to remain vigilant and report any unusual symptoms in larch or other tree species to the Department – telephone DARD Helpline on 028 9052 4999.