The fight against lethal tree diseases such as oak processionary moth is stymied by indecisive chiefs who move too slowly on policy, conference delegates have heard.
London Tree Officers Association chair David Lofthouse told last week's Trees in Crisis conference at Kew that biosecurity was a much broader problem and the most pressing concern was the oak disease. "But there's a lack of coherence about responses," he said.
"A while ago there was a programme of eradication. It's been downgraded to containment and more recently there's been no consensus on whether it can be eradicated or not. This is about human as well as plant health.
"If we keep approaching it in this way we are heading for disaster. Pine processionary moth is already in Paris and we could have the problem by next summer. What's the idea? What's the plan? Things move far too slowly."
Also speaking at the conference, hosted by Treework Environmental Practice, Bartlett Tree Research Laboratory plant physiologist and manager Dr Glynn Percival said chemical control was needed for oak processionary moth.
"Control is demanding and there is no silver bullet," he said. "But we can look at promoting vitality and alleviating stresses. Decompaction, mulching and fertilisation help."
He said the laboratory was funding a PhD into the effects of charcoal in the control of disease such as Phytophthora. Meanwhile, he described other work that showed that oyster shells helped against honey fungus (see box).
Oak decline - Alternative approaches
The owners of Hazeleigh Wood, John and Maureen Bissell, used charcoal dust and ash to combat acute oak decline.
They scattered the ash around the base of 70 trees in their 250ha wood near Maldon. Rain washed it into the roots and improved tree health.
The idea came from slash-and-burn techniques in the Amazon, where charcoal was used in agriculture.
Californians, meanwhile, used volcanic ash and oyster shells to try to promote "sudden oak life".