The establishment of fast-growing teak plantations in Indonesia provides opportunities for shorter harvesting periods. However, it also poses challenges on wood utilization due to juvenility and growth stress-related defects. This study investigated growth stress levels and some wood properties of 10-year-old fast-growing teak grown in Gunungkidul Regency, Yogyakarta. The strain gauge method was used to measure longitudinal surface released-strains (LRS), tangential surface released-strains (TRS), and longitudinal internal residual strains (IRS). Wood specimens were also collected near each strain measurement point for the analysis of wood properties. The results showed LRS values ranging from −1243 to 320 με, TRS values ranging from −779 to 382 με, and IRS values ranging from −589 to 786 με. Meanwhile, radial variations in fiber length, modulus of elasticity, and lignin content were observed. Significant correlations were found between IRS values and microfibril angle, fiber length, modulus of elasticity, lignin content, and hemicellulose content, while no significant correlations were observed between LRS and TRS values and wood properties. These findings suggest a moderate level of growth stress. Additionally, the results also indicate that this 10-year-old fast-growing teak is still in the juvenile stage. Therefore, its utilization should be performed with caution.

中文翻译：

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日惹古农基杜尔 10 年生速生柚木的生长应力和木材特性

印度尼西亚快速生长的柚木种植园的建立为缩短采收期提供了机会。然而，由于幼年性和生长压力相关的缺陷，它也对木材利用提出了挑战。本研究调查了日惹 Gunungkidul 县种植的 10 年树龄快速生长柚木的生长应力水平和一些木材特性。应变片法用于测量纵向表面释放应变（LRS）、切向表面释放应变（TRS）和纵向内部残余应变（IRS）。还在每个应变测量点附近采集了木材样本，以分析木材特性。结果显示LRS值范围为-1243至320με，TRS值范围为-779至382με，IRS值范围为-589至786με。同时，观察到纤维长度、弹性模量和木质素含量的径向变化。IRS值与微原纤维角度、纤维长度、弹性模量、木质素含量和半纤维素含量之间存在显着相关性，而LRS和TRS值与木材特性之间没有观察到显着相关性。这些发现表明存在中等程度的生长压力。此外，结果还表明，这棵10年生的速生柚木仍处于幼年阶段。因此，其使用应谨慎。