The seminar was led by Dr Glynn Percival, manager of Bartlett Tree Research Laboratories, Jon Banks of Bartlett and Barcham's Keith Sacre, who began the day by reminding delegates that visual assessment depends on individual expertise, and that not all problems are visible.
Sacre spoke about tests to determine the physiological health of a tree and said he appointed Bartlett to carry out tests on 15,000 of Barcham’s trees, which found that 98 per cent of the trees tested were "fit for purpose".
He then handed over to Percival, who said the evolution of the system continues every year. "It shows us how phenomenally complicated trees are, with leaves showing a huge variation between species," he said.
The next session was led by Jon Banks, who runs Bartlett's diagnostic laboratory and is undertaking a PhD into drought stress in Acers. He discussed alternative methods of stress detection in trees, and considered water potential as a measure of plant vitality.
After lunch there was a session on the Arborcheck system, which is a method of tree health analysis by directly measuring the physiological condition of a leaf.