Plant Health

Plant pest Phytophthora ramorum


Report no:

Publishing: 01.06.2023

Key message:

VKM shall update a risk assessment of the plant pest ramorum disease (Phytophthora ramorum) in Norway.

The Norwegian Food Safety Authority has commissioned the assessment for use for their work in regulating plant pests.


The previous risk assessment of r Phytophthora ramorum ( sudden oak death) is from 2009. Since then, the pathogenhas been detected in Norway repeatedly, primarily in Western Norway, in parks, in garden centres, and in nurseries.

Sudden oak death has mainly affected ornamental plants in the genus Rhododendron, but discoveries have also been made in guelder rose, Pieris, Kalmia, lilac, and in American oak trees. Recently, in September 2009, natural infection of the disease was detected in blueberries.


In the update, VKM will describe genetic lines of rthe pathogen, and summarise updated knowledge about its occurrence in Norway as well as in Europe and elsewhere in the world.

The final report shall contain up-to-date information about host plants for sudden oak death. In addition, VKM shall assess possible points of entry, including identifying types of host plants and other infectious elements which may pose a particularly high risk to introducing pathogento Norway.

VKM will also model effects Phytophthora ramorum would have if it were to spread to other areas in Norway than where it has already been identified. These possible effects include damage to various types of cultivated plants, forests and sprawling plants, and any other economic and environmental consequences that could arise.

The assignment also includes identification of relevant risk-reducing options.

Project group

The project group consists of:

• Iben Margrethe Thomsen, member of the Panel on Plant Health (Scientific leader)
• Beatrix Alsanius, member of the Panel on Plant Health
• Paal Krokene, member of the Panel on Plant Health
• Sandra Wright, member of the Panel on Plant Health
• Daniel Flø, VKM Secretariat
• Micael Wendell, VKM Secretariat (Project manager)

The report will be approved by VKM's Panel on Plant Health. It is scheduled to be published on June 1, 2023.


Micael Wendell

Project manager, PhD

T: +47 21 62 28 22
Send e-mail

The Norwegian Scientific Committee for Food and Environment

T: 21 62 28 00

P.O. Box 222 Skøyen
0213 Oslo

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