Denny Irawati

Variation in tree growth characteristics, stress-wave velocity, and Pilodyn penetration of 24-year-old teak (Tectona grandis) trees originating in 21 seed provenances planted in Indonesia

Growth characteristics [stem diameter (D), tree height (H), and bole volume (V)], stress-wave velocity (SWV), and Pilodyn penetration (P) were measured for 21 seed provenances of 24-year-old teak trees planted in Indonesia to characterize variation in tree growth characteristics, SWV, and P among seed provenances. Broad-sense heritability and correlations between the measured characteristics were also determined. Significant differences for all measured characteristics were observed among provenances, indicating that these characteristics are genetically controlled. Broad-sense heritabilities of growth characteristics, SWV, and P are moderate values. These results indicate potential for improving growth characteristics and wood properties of teak trees with the help of breeding programs. Highly significant positive correlations were observed among the growth characteristics, suggesting that they are closely related. In contrast, no significant correlations were observed between the growth characteristics and SWV, indicating that they are independent. We conclude that mechanical properties are also important criteria for selecting plus trees in tree breeding programs. Principal component analysis revealed that seed provenances from Indonesia (Bangilan, Deling, and Randublatung) and India (Malabar and Central Province) have high scores of growth characteristics and SWV.

Basic properties of Acacia mangium and Acacia auriculiformis as a heating fuel

We examined the potential bioenergy of two Acacia wood species, Acacia mangium (Am) and Acacia auriculiformis (Aa). The objectives of this study were to assess the basic properties (anatomical, physical, and chemical-related properties) and to compare bioenergy potentials among these two Acacia species from Indonesia. Six 3-year-old trees were randomly selected from plantation forest on South Kalimantan. Statistically, no significant difference was found in calorific value between the two species of Acacia or position in the stem. The calorific values ranged from 16.6-17.5 kJ/g in the Am species and from 16.8-17.4 kJ/g in the Aa species. Based on these properties, both of these species have the same potency as a heating fuel resource. The top (T) position which usually has a smaller diameter and lower economic value may be used as a heating fuel source with its potency of the calorific value which is equal to the other parts of the stem. The calorific value in both Acacia wood was influenced by vessel fre...

Ozone treatment of spent medium from Auricularia polytricha cultivation for enzymatic saccharification and subsequent ethanol production

We examined the enzymatic saccharification and ethanol fermentation of the spent media (SMs) from Auricularia polytricha cultivation using wood meals of Falcataria moluccana, Shorea sp., and Tectona grandis. Although the hydrolysis weight decrease and reducing sugar yield were higher in SM of F. moluccana, the ethanol yield was higher in SM of Shorea sp. Ozone treatment of SM further increased the hydrolysis weight decrease, reducing sugar, and ethanol yields in Shorea sp. These results indicate that SM of A. polytricha is a suitable biomass material to produce fermentable sugars for ethanol production, and that ozone treatment is a suitable method for increasing the ethanol yield.

Fiber Morphology and Physical Characteristics of Gigantochloa atter at Three Different Ages and Heights of Culms for Better Utilization

Fiber morphology and basic characteristics of Legi bamboos (Gigantochloa atter) growing on Yogyakarta were studied considering their age and height positions in the culms. Culms of 4, 16, and 40 months were har- vested, and their total lengths were measured. The length, diameter, and wall thickness of each internode were measured. All the sample culms were divided into three different parts along the height, and their fiber dimension and physical properties were observed. The data obtained were analyzed by analysis of variance. The results showed that the culms had a diameter of 5.8 to 10.8 cm. The lowest internodes always showed the shortest length and the thickest wall. The culms had an average fiber length of 2.41 mm and Runkel ratio of 0.61. Fiber length was affected by the height, while fiber diameter, lumen diameter, and fiber wall thickness were affected significantly by the age of the culms. The culms had high green moisture content (GMC) of 157.89%, and basic density (BD) of 456.67 kg.m -3 , a total longitudinal shrinkage of 0.35%, and relatively low R/T shrinkage ratio. The interactions between age and height were affected GMC and BD.