Symptoms of Phytopthora pluvialis.
Woodland managers, landowners, the forest industry and tree nurseries are being urged to be vigilant following the discovery of Phytophthora pluvialis near Loch Carron in the north-west of Scotland.
Following this finding, Scottish Forestry introduced a demarcated area around the infected site to help avoid accidental spread of the pathogen.
P. pluvialis is a fungus-like pathogen known to affect a variety of tree species, including western hemlock, Douglas fir, tanoak and several pine species (in particular radiata pine).
It is reported to cause needle cast (where needles turn brown and fall off), shoot dieback, and lesions on the stem, branches, and roots. It was found for the first time in the UK in 2021 on western hemlock and Douglas fir; it has been detected in Devon, Cornwall and Cumbria in England and now near Loch Carron in Scotland. For more information on P. pluvialis, a symptom guide has been prepared based on what has been observed in England. Landowners are asked to report any suspect trees via TreeAlert.
Research is ongoing to understand if other potentially susceptible species could become impacted. This will help inform which control measures are appropriate and the potential impact this pathogen could have on the landscape and the forestry sector.
For more information: www.gov.uk/guidance/phytophthora-pluvialis.
This article was taken from Issue 196 Spring 2022 of the ARB Magazine, which is available to view free to members by simply logging in to the website and viewing your profile area.