Growth response and wound occlusion in pruned Corymbia torelliana

A field trial to examine growth and wound healing of pruned Corymbia torelliana was established in a 40-month-old plantation in western Guangdong, China. It included: (1) pruning all branches up to stem diameters of 5, 6, 7 or 8 cm, (2) wound protection with wax or paint and (3) a control with no pruning. Measurements of growth and wound occlusion taken at various intervals up to 12 months after pruning showed that pruning generally impeded height growth, promoted diameter at breast height (dbh) growth and slightly increased taper. The optimal pruning intensity for tree growth was pruning up to stem diameter of 8 cm. Lower wound occlusion rates occurred in heavier pruning intensities. The optimal intensity for rapid wound occlusion was pruning up to stem diameter of 7 or 8 cm. Paint resulted in better occlusion than wax. The fastest wound occlusion occurred in stem section of height 2.51 to 5.35 m above the ground. Rate of wound occlusion up to 12 months showed correlations with dbh increment, initial wound size and pruning intensity.