Phony Peach Threatens UK Trees

Ash Dieback devastated UK ash tree populations and rocked the conservation world. Now, the UK is again on high alert for signs of the Phony Peach disease, Xylella fastidiosa. There are warnings that X. fastidiosa could make Ash Dieback look like a walk in the park. The disease could wipe out populations of multiple species of tree, unlike many other diseases which are restricted to one or two species. In the case of X. fastidiosa the EU have stopped printing the hard copy of host plants and now only publish it online as the list is so extensive.

The disease has attacked citrus and coffee plantations in the USA, causing severe damage, and has decimated more than a third of New Jersey’s urban trees. It was first confirmed in Europe three years ago when it rampaged through Italian olive plantations. A sub-species of X.fastidiosa has been identified in Southern France where it has caused major damage to vines and lavender plants. Symptoms include wilting, dieback and leaf scorches as well as stunted growth.

Though previously the UK has been thought to be safe, as the climate would not support X. fastidiosa, a new, cold tolerant, strain of the disease has just been identified in France and Corsica. This has put horticulturists in the UK on high alert.

An outbreak in the UK would lead to stringent emergency controls being introduced, all known host plants within a 100 metre radius of the outbreak would be destroyed and sweeping restrictions would be placed on plant movements within a 10km buffer zone of the affected area for five years. This could have major imapcts on gardening and landscaping work in the UK. For example, it has been estimated that an outbreak in Canary Wharf would shut down landscaping work in London.

Whilst this is clearly a major concern for the horticultural industry, conservation organisations should also be getting concerned. Woodland and tree planting has declined massively in recent years, despite pledges by the government to increase the amount of UK woodland, it is thought that planting rates could drop to around 1,600 hectares in 2015/16. Add to these falling rates of new planting a devastating disease and the UK could stand to lose a vast amount of its trees. Trees have a stabilising effect on the climate, they improve air quality by acting as a sink for pollutants and the stabilise river banks and hillsides, helping to prevent flooding. In addition trees and woodlands provide some of our most valuable wildlife habitat.

We stand to lose an incredible amount of our tree and woodland cover if X.fastidiosa finds a foothold in the UK. Conservation groups need to start joining their voices with the horticultural world to call for stricter controls on plant import and exports to the UK to protect our native tree species from decimation.

Source: The Guardian