© 1973 by Institute of Chartered Foresters
Editorial |
Some Aspects of the Relationships between Growth Vigour, Canker, and Dieback of European Larch
Department of Forestry, University of Oxford1
From the detailed sampling of two European larch provenance trials in Scotland, an increase in canker coincident with outbreaks of epidemic dieback was demonstrated. There was generally less cankering on unthrifty trees although this was not correlated with the severity of dieback. There was a general positive correlation between growth vigour, as measured by mean annual radial increment, and incidence of canker healing, and it was shown that cankers are initiated on stems of all ages. Although there was no overall statistical correlation between growth vigour and subsequent severity of dying back, the most unthrifty trees were considerably less affected than the most vigorous. An increase in suitable canker infection courts as a result of dieback is suggested, and the possible roles of climatic factors, Adelges spp. and viruses in the dieback syndrome compared. It was concluded that virus transmission by Adelgids merits further investigation.