Author : Dusit Wechakit

Summary : A species trial and three provenance trials of Eucalyptus camaldulensis, Acacia mangium, and Gmelina arborea established at the ASEAN New Zealand Afforestation Project (ANZAP) in Tarlac, Philippines were assessed from April to June 1994. The study soughtto determine the performance of the trees in terms of survival, diameter at breast height (DBH), total height, merchantable height, crown length, crown diameter, stem straightness, persistence of the main stem, branch size, health condition and merchantable volume. The best species/provenance of each trial was also determined. The species trials (7 species) were established in 1980 using randomized complete block design (RCBD) with four replications. Eucalyptus camaldulensis (7 provenances) and Acacia mangium (10 provenance) provenance trials were established in 1985, while Gmelina arborea (10 provenances) was established in 1986. These three provencance trials were laid out in RCBD with five replications. These experiments were monitored, adequately maintained and assessed by ANZAP until 1987 only owing to financial constraints. In this study, the analysis of variance (ANOVA) was used to determine whether or not the different species or provenances in each trial are significantly different from each other in terms of the different performance indicators. When necessary, subsequent comparisons of means were done using Duncan's Multiple Range Test (DMRT). The total score in all performance indicators was used to determine the best species/provenance in each trial. In the species trial, there were significant differences among the species in all performance indicators except in crown length and diameter. Agoho (Casuarina equisetifolia) exhibited the best performance in total height (15.94 m), merchantable height (10.091 m), crown length (8.27 m), stem straightness, persistence of the main stem, and branch size. Ipil-ipil had the best survival rate (85 percent) and crown diameter (3.63 m).