Chemical properties of juvenile wood of superior teak “Jati Mega” planted in Gunungkidul

Superior clones called “Jati Plus Perhutani (JPP)” have been developed and bred to produce short-rotation teak trees. The present study aimed to evaluate the chemical characteristics of juvenile wood from superior clonal teak trees grown in Gunungkidul (Jati Mega), Yogyakarta. The study used superior juvenile wood (SJW) samples from eight five-year-old superior clonal trees. For comparative purposes (seed propagation), conventional juvenile wood (CJW) samples from three seven-year-old trees and conventional mature wood (CMW) samples from three 65-year-old trees were used. In the case of the SJW samples, heartwood had significantly higher extractive content than sapwood. The effects of tree group on all chemical properties, except for α-cellulose and lignin content, were significant across all the three groups. With regard to cell wall components, the SJW samples had higher hemicellulose content in heartwood than the CMW samples. The SJW samples also had lower ethanol-toluene extractive content, solubility in hot water, solubility in 1% NaOH, ash content, and acid-insoluble ash content in heartwood than the CMW samples. However, pH values were higher in the SJW samples than in the CMW samples. Furthermore, the SJW samples had lower ethanol-toluene extractive content in sapwood and higher pH values than CJW