Selection and Screening of Superior Genotypes for Quality Planting Stock Based on Vegetative Growth Performance of Some Selected 12-Year-Old Acacia Species

Production of quality wood is a big problem in forestry plantation since trees grown in plantation of some high value temperate and tropical hardwood species tend to produce low value, short butt logs and bolts due to crooked stems, low fork heights and delayed shedding of lower branches. Result from existing Acacia plantation in Malaysia indicated that most existing Acacia plantation trees especially Acacia auriculiformis and Acacia mangium, fork very heavily which leads to the formation of multiple leaders more than one and some are fork so close to the ground that they will produce little to no merchantable wood. In this context, a research study was initiated to select and recommend the best performing tree species or provenance suited for timber production in Malaysia with respect to growth and other characteristics. Species/provenance/progeny test was conducted on four species of Acacia namely, A. mangium, A. auriculiformis, A. crassicarpa and A. aulococarpa, each with 4 provenances originated from Papua New Guinea (PNG) and Queensland (QL). The growth performance of the provenances was monitored in terms of some quantitative and qualitative characteristics to evaluate the genetic variation and growth performance of a base breeding population. 20 progenies for each species were selected and randomly planted with 16 trees representing each progenies in a trial plot laid out in a randomized complete block design consisting of four blocks as replication. The study showed that there were significant different (p mangium performed better compared to other Acacia species in all of the aspect tested and it was followed by A. crassicarpa, A. aulococarpa and A. auriculiformis. There were also significant differences between provenance within regions and progenies within provenances in all quantitative and qualitative traits tested in this study. Generally, provenance and progenies selected from PNG excelled those from QL both in quantitative and qualitative characteristics. The top performing progenies of Acacia species are CG 1854 of (Bensbach WP) and KN000107 (SW of Boset WP) of A. mangium, BVG2609 (Bensbach WP) of A. crassicarpa, BVG 00835 (WP Morehead) and MM1016 (Arufi E Morehead WP) of A. aulococarpa and JSL363 (Wenlock River) and BVG 2657 (Bansbach) of A. auriculiformis.