Pruning and fertiliser effects on branch size and decay in two Eucalyptus nitens plantations

The effect of a high rate of fertiliser addition, (900 kg ha-1 nitrogen (N):150 kg ha-1 phosphorus (P)) on pruning associated decay was investigated at two N and P deficient sites in Tasmania, Australia. Decay infections from pruned stubs were found to be more common in trees that received additions of fertiliser N and P, but fertiliser addition was not found to have an effect on basic density, lignin or the concentrations of extractives. Crown depth, and branch size were greater, and kino production reduced on trees that received fertiliser N and P. The incidence of decay infections in the pruned branch stubs increased with the frequency of living and large branches. Hence, improved tree nutrition increased the longevity and size of branches, thereby leading to an increased incidence of decay infections. © 2006 Elsevier B.V. All rights reserved.