Growth responses of Eucalyptus globulus and E. nitens to pruning and fertiliser treatments in a plantation managed for solid-wood products

Abstract

The responses of Eucalyptus globulus and E. nitens to pruning (removal of 0 or 60% of the green crown depth) in two lifts and nitrogen (N) fertiliser application (0 [N0], 100 [N1], 300 [N3] and 500 [N5] kg N ha–1) were compared at a site in south-east Tasmania under conditions where both species can be successfully grown. Pruning reduced growth of both species, but the final measured volume (at age 5.7 years) of pruned trees in the N3 and N5 treatments was greater than in the unpruned trees in the N0 treatment. Eucalyptus nitens exhibited superior growth over the course of the experiment and showed a larger volume response to applied N than E. globulus during one growth period. Eucalyptus nitens had a higher incidence of decay infections in pruned stubs because of its tendency to have larger branches than E. globulus, though the overall incidence of decay was very low.

Keywords: branch size, clear wood, Eucalyptus, plantations, pruning,  solid-wood, wood decay