tailieunhanh - Card Project Progress Report:"Sustainable and profitable development of acacia plantations for sawlog production in Vietnam " MS3

Research Acacia logs processed in sawmills in Vietnam indicated that to improve profitability acacia sawlog production for growers, the following plants are necessary and sign standards should be improved through a combination of selected species genetic improvement, and forestry. Survival rate of survival is important to stand united and timber yield Ability to quickly develop a sawlog production in the shortest possible cycle (login as small as 2 m length and 15 cm diameter is frequently sawn). | CARD Project Progress Report 032 05VIE Sustainable and profitable development of acacia plantations for sawlog production in Vietnam MS3 Review of Acacia genetic resources and propagation methods to support sawlog production in Vietnam . Harwood1 Le Dinh Kha2 Ha Huy Thinh2 and Phi Hong Hai2 1Ensis Genetics Private Bag 12 Hobart 7001 Australia 2Research Centre for Forest Tree Improvement Forest Science Institute of Vietnam Chem Hanoi Vietnam Abstract Study of the processing of acacia logs in Vietnam s sawmills indicates that to improve profitability of acacia sawlog production for tree growers the following essential tree and log criteria need to be improved through a combination of species selection genetic improvement and silviculture. Survival - high rates of survival are important for stand uniformity and wood yield Rapid growth - ability to produce a sawlog in the shortest possible rotation logs as small as 2 m in length and 15 cm small-end diameter are routinely sawn Good stem form - reasonably straight main stem minimum forking and light branching will maximize the proportion of the tree s production that can be sold as sawlog Defect-free wood - sawlogs must be free of heart-rot loose knots and other defects that cause visible defects in the sawn boards. The history of species and provenance testing and genetic improvement in Vietnam and the development of selected acacia hybrid clones is reviewed. From this review the best planting materials for sawlog plantations and the best propagation methods have been identified. Selected clones of the acacia hybrid A. mangium x A. auriculiformis and the best improved planting material of A. auriculiformis selected clones and improved seed and A. mangium improved seed are the best suited acacia varieties for sawlog production and are already proven in this role in lowland regions of Vietnam receiving at least 1000 mm annual rainfall. Details of superior germplasm of these species are provided in the report. A. .