FIVE-YEAR GROWTH PERFORMANCE OF <em>ACACIA</em> <em>PEREGRINALIS</em>, <em>A. </em> <em>MIDGLEYI</em> AND <em>A. </em> <em>CELSA</em> AT KOLAPIS B IN EASTERN SABAH, MALAYSIA

Abstract

A provenance trial was planted at Kolapis B, in eastern Sabah, Malaysia in 1995, testing 21 Acacia provenances, at that time classified as A. aulacocarpa. Nineteen of the provenances, now classified as A. peregrinalis, were from the southern lowlands of New Guinea and the other two, one now classified as A. midgleyi and the other as A. celsa, were from north Queensland, Australia. The trial was assessed for survival and growth at five years of age. Survival was generally good, averaging 82% for the trial, with no significant differences among species or provenances. The three species differed significantly (p< 0.001) in their growth performance of height and diameter at breast height (dbh), with all A. peregrinalis provenances clearly outperforming A. midgleyi
and A. celsa. Species mean height for A. peregrinalis was 18.0 m (provenance means ranged from 16.4 to 19.1 m), and mean dbh was 16.2 cm (provenance means ranged from 14.9 to 17.7 cm). Provenance differences in height and dbh were not statistically significant. Acacia celsa, had a mean height of 15.2 m and dbh 11.9 cm, while the corresponding figures for A. midgleyi were 13.2 and 9.4 cm. Acacia peregrinalis was also significantly (p < 0.05) superior to the other two species with respect to stem form, and appears to have good prospects as a plantation species in eastern Sabah.