Wood properties of 7-year-old balsa ( Ochroma pyramidale ) planted in East Java

Abstract

The effect of radial growth rate on wood properties was evaluated for 7-year-old balsa trees grown in plantation forest in East Java, Indonesia. The standing trees in the experiment site in the plantation were categorised into three groups (slow-, medium-, and fast-growth) according to their stem diameter. Mean values of stem diameter, tree height, and stress-wave velocity (SWV) were 311 mm, 25.4 m, and 2.96 km/s, respectively. No significant correlations were found between growth characteristics and SWV of stems. The mean values of basic density, compressive strength parallel to grain, modulus of elasticity, and modulus of rupture were 0.14 g/cm³, 10.4 MPa, 4.53 GPa, and 22.9 MPa, respectively. The wood properties were almost constant up to 80-mm from the pith, and then they sharply increased toward the bark. Therefore, separation of the wood at around 80 mm from the pith is likely to be useful for wood industries.