English yew threatened by disease

Concern is growing that the English yew tree, used to make the famed longbows used in the Battle of Agincourt, may be susceptible to a new deadly tree disease just discovered near Loch Lomond, Scotland.

Anxious Forestry Commission officials are waiting for test results to see if 27 dead or dying English yews in the grounds of Balloch Castle Country Park have been affected by Phytophthora lateralis (P. lateralis), a fungus-like pathogen never previously found in Britain.

Commission scientists say the root-killing disease, mostly known in the western US and Canada, was “highly likely” to be the cause as it had already been confirmed as causing the death of a Lawson’s cypress in the castle grounds, with many of the other 80 cypresses nearby showing similar symptoms.

"This is a very worrying development,” said Dr Bob McIntosh, director of forestry for Forestry Commission Scotland. “P. lateralis is a particularly virulent pathogen, and very few trees survive an attack.

"Although its main victim is Lawson's cypress, it can kill other species, particularly Pacific yew (Taxus brevifolia), a close relative of our native English yew (Taxus baccata).

"Scientists in our Forest Research agency are researching the outbreak as quickly as possible to find out as much as they can, although the current poor weather is hampering the investigations.

“We are also working closely with West Dunbartonshire Council to fell and destroy the dead and dying trees and to implement biosecurity measures at the park to minimise the risk of spreading the disease.”

English yew is prized for use as veneer in the furniture industry, while Lawson’s cypress and its various cultivated varieties are some of the most important conifers in the UK’s ornamental plant trade.

"It could be serious for the ornamental plant industry if it became established in Britain,” added Dr McIntosh.

The Forestry Commission is not aware of any previous records of P. lateralis infection of English yew.