Thirteen year results from a Spotted Gum provenance trial in the Wellington catchment of Western Australia

Abstract

Summary Sixteen provenances of spotted gum including eight provenances of Corymbia variegata, seven provenances of Corymbia maculata and one provenance of Corymbia henryi were assessed for growth, form and parrot damage in a trial south-west of Darkan, in Western Australia. C. henryi yielded the greatest mean annual volume increment at thirteen years (2.6 m'ha?1 yr1), followed by C. maculata (2.5 m3 ha−1 yr−1) and C. variegata (2.1 m3 ha−1 yr−1). Significant differences were found between species and between provenances within species for percentage of single stemmed trees and mean straightness of single stemmed trees. C. variegata yielded the highest average of 15.7% single stemmed trees, C. maculata, 11.6% and C. henryi, 4.5%. C. maculata yielded the straightest single stemmed trees (4.1 points out of a possible 6) followed by C. henryi (3.7 points) and then C. variegata (3.6 points). C. maculata sustained the lowest incidence of visible parrot damage with 55.9% of trees untouched. C. variegata and C. henryi were similar with only 38.6% and 37.5% of trees undamaged. Correlations between measured parameters and environment at seed source showed strong correlations (r = 0.8) between altitude and percentage of single stemmed trees in C. variegata. Within C. maculata, height was correlated with incidence of parrot damage (r = 0.8).