Sifat Kimia Kayu Jati (Tectona grandis) dengan Busuk Hati

MUKHLIS ARDIANSYAH, Dr. Ganis Lukmandaru, S. Hut., M. Agr.

2014 | Skripsi | TEKNOLOGI HASIL HUTAN

Jati merupakan salah satu jenis kayu unggulan di Pulau Jawa. Meski demikian, kayu jati tidak dapat dipastikan akan selalu diproduksi dalam kondisi bagus. Bahkan kayu yang terlihat bagus dari luar belum tentu bagus juga bagian dalamnya, seperti halnya kayu yang mengalami busuk hati. Sampai saat ini, belum diketahui secara pasti penyebab busuk hati pada pohon jati. Penelitian ini bertujuan untuk untuk mengetahui perbedaan sifat kimia di bagian padat dan bagian lapuk serta menganalisis variasi serangan busuk hati yang berbeda, dan membandingkan kecenderungan sifat kimia pada arah radial antara kayu busuk hati dan kayu sehat. Contoh uji yang digunakan dalam penelitian variasi dalam pohon berasal dari Gunungkidul, yang terdiri dari 1 pohon yang terkena busuk hati kemudian dibagi menjadi bagian pangkal, tengah, dan ujung serta ditebang 1 pohon sehat sebagai pembanding. Sedangkan penelitian variasi antar pohon berasal dari KPH Randublatung, Perum Perhutani, yang terdiri dari 3 pohon yang terkena busuk hati dan 1 pohon pembanding. Bagian kayu busuk hati yang diamati meliputi bagian padat (gubal, teras luar, teras dalam) dan bagian yang lapuk. Dari setiap bagian, diambil serbuk berukuran 40-60 mesh untuk diuji sifat kimia kayunya. Sifat kimia yang diuji adalah kadar holoselulosa, alfa-selulosa, lignin, ekstraktif etanol-toluen, ekstraktif air panas, kelarutan dalam NaOH 1%, abu, dan nilai pH. Analisis yang digunakan adalah statistik deskriptif. Kayu teras padat yang menunjukkan gejala busuk hati diamati cenderung memiliki nilai kadar ekstraktif air panas lebih tinggi dari kayu sehat, perbedaan kecenderungan dinding sel lebih diamati pada variasi dalam pohon. Kayu teras lapuk yang menunjukan gejala busuk hati memiliki nilai kadar alfa-selulosa lebih rendah sedangkan kadar lignin, kelarutan NaOH 1%, ekstraktif air panas, dan abu lebih tinggi dari kayu sehat. Berdasarkan data-data tersebut, penyebab busuk hati diindikasikan akibat jamur pembusuk coklat.Kayu yang menunjukkan gejala busuk hati dengan diameter lebih besar memberi nilai kadar alfa-selulosa lebih rendah sedangkan kadar lignin, kelarutan NaOH 1%, KEAP, abu, dan nilai pH lebih tinggi dimana perbedaan ini lebih terlihat pada variasi antar pohon. Perbedaan kecenderungan sifat kimia arah radial khususnya di gubal-teras dan teras dalam – teras luar kayu yang terserang busuk hati dengan kayu sehat lebih terlihat khususnya dalam distribusi komponen kimia dinding sel. Kata kunci : Tectona grandis, busuk hati, sifat kimia, lapuk, arah radial

Teak wood is considered as a superior timber in Java. However, it could not be ascertained that the best condition is be produced every time. Even the wood looks sound from the outside, it isnot necessarily a sound wood inside, as a case of heart-rot wood. Nowadays, it still remains unknown of the cause of such abnormality. This study aimed to determine the differences in the chemical properties of the solid parts and decayed inner heartwood to analize the different variation in the intensity of heart-rot attacked wood, as well as to compare the tendency of the chemical properties in the radial position between the heart-rot affected and normal woods. The materials used of this study for intra-tree variation were from Gunungkidul Region. It consisted of one heart-rot affected tree which the samples were then divided axially (the base, middle, and top). In addition, a normal tree for comparison was also cut. The materials used for between-tree variation were felled from KPH Randublatung, Perum Perhutani. It comprised of 3 heart-rot affected trees and a normal tree for comparison. The samples of heartrot wood observed were solid parts (sapwood, outer hearwood, inner heartwood) and the decayed inner heartwood. From each section, the samples were sized into 40-60 mesh powder for testing the chemical properties of wood. Chemical properties tested were holloselulose, alfa-cellulose, lignin, ethanol-toluene extractive, hot water extractive, solubility in NaOH 1%, and ash contents, as well as thepH value. The data analysis used in this study was descriptive statistic. The solid heartwood affected by heart-rot showed the increasing in the hot water extractive content level. Further, the difference tendency was more observed in the cell wall components with regard to intra-tree variation. Decayed inner heartwood,which is affected by heart-rot, had a decreasing level of alphacellulose content while those increasing level in lignin, solubility in 1 % NaOH, hot water extractives, and ash contents was found. Based on these data, the caused of heart-rot was indicated by the brown-rot. Teakwood affected by heart-rot with a bigger diameter showed a decreasing in alpha–cellulose content while the level of lignin, solubility in 1 % NaOH, hot water extractive, and ash contents, also the pH values increased. Those differences were more visible in the between–tree variation. The different tendencies in the chemical properties in radial direction were more noticed especially in sapwood-heartwood and inner heartwood-outer heartwood of affected heart-rot and normal wood. This is due to the distribution of the chemical components of the cell wall. Keywords : Tectona grandis, heart-rot, chemical properties, decay, radial direction 1) College Student, Departement of Forest Product Technology, Forestry Faculty, UGM 2) Lecture, Departement of Forest Product Technology, Forestry Faculty, UGM

Kata Kunci : Tectona grandis, busuk hati, sifat kimia, lapuk, arah radial