PENGARUH UMUR POHON, BONITA DAN POSISI AKSIAL BATANG TERHADAP KUALITAS KAYU JATI SEBAGAI BAHAN MEBEL (Studi Kasus di KPH Kendal)

YUSTINUS SURANTO, Prof.Ir. TA Prayitno, M.For. Ph.D.; Prof. Dr. Ir. Djoko Marsono; Dr.Ir. JP Gentur Sutapa, M.Sc.

2015 | Disertasi | S3 Ilmu Kehutanan

Industri mebel berbahan kayu jati menggunakan kayu muda. Penelitian bertujuan (1) mengetahui pengaruh umur pohon, bonita dan posisi kayu dalam batang dan interaksinya terhadap 23 sifat kayu, (2) menentukan peringkat kualitas kayu jati. Pohon jati 36 batang ditebang hutan KPH Kendal Provinsi Jawa Tengah yang mewakili kelas umur (III, IV dan V) dan bonita (3, 3,5, 4 dan 4,5) dengan tiga ulangan. Pembedaan setiap batang menjadi posisi pangkal, tengah dan ujung batang diperoleh 108 unit perlakuan. Setiap unit diukur sifat kayu berdasarkan American Standard Testing and Material atau British Standard. Analisis varians dan MRT Duncan digunakan membedakan sifat kayu dan analisis diskriminan untuk pembedaan kualitas kayu. Hasil penelitian menyimpulkan enam butir kesimpulan. (1) Interaksi kelas umur, bonita dan posisi aksial batang mempengaruhi permukaan bebas cacat pemboran longitudinal. (2a) Interaksi kelas umur dan bonita mempengaruhi proporsi kayu teras, dimensi lebar lingkaran tahun, kadar ekstraktif, sifat pembentukan dan pembubutan. (2b) Interaksi bonita dan posisi batang mempengaruhi keteguhan belah dan sifat pembubutan. (3a) Kelas umur mempengaruhi proporsi jari-jari, proporsi serat, berat jenis, dan penyusutan radial. (3b) bonita mempengaruhi proporsi pembuluh, proporsi parenkim, berat jenis, penyusutan tangensial, keteguhan tekan sejajar serat, kekuatan geser, dan kekerasan. (4) Interaksi kelas umur IV, bonita 3,5 dan posisi pangkal batang menghasilkan kelas kualitas peringkat tertinggi 2,08, sebaliknya interaksi kelas umur V, bonita 3 dan posisi ujung batang menghasilkan kelas terendah 2,79. (5a) interaksi kelas umur V dan bonita 3,5 menghasilkan peringkat kelas kualitas tertinggi, 2,12 dan interaksi kelas umur III dan bonita 4,5 menghasilkan peringkat terendah 2,79. (5b) interaksi kelas umur IV dan pangkal batang menghasilkan kelas kualitas tertinggi 2,29 dan interaksi kelas umur V dan posisi ujung batang menghasilkan kelas terendah 2,67. (5c) interaksi bonita 4 dan pangkal batang menghasilkan kelas kualitas tertinggi 2,27, sedang interaksi bonita 4,5 dan ujung batang menghasilkan kualitas terendah 2,71. (6a) Kelas umur V, IV dan III menghasilkan kualitas kayu peringkat 2,29 dan 2,42 serta 2,50. (6b) Bonita 3,5, 4, 4,5 dan 3 menghasilkan kualitas kayu peringkat 2,33; 2,46; 2,50 dan 2,58. (6c) Posisi pangkal, tengah dan ujung menghasilkan kayu berkualitas 2,37 dan 2,41 serta 2,46

Teak furniture industry using wood young. The research was aimed to ( 1 ) determine the influence of tree age, site quality index and longitudinal wood position in the stem and their interactions to 23 wood properties , ( 2 ) rank the quality of teak wood. Teak tree of 36trunks were felled of Kendal forests district of Central Java Province representing an age classes (III , IV and V ) and site quality index ( 3 , 3.5 , 4 and 4.5 ) with three replications. Each stem was divided into butt, middle and upper positions to obtain 108 treatment units. Each treatment unit was measured its wood properties which was elaborated based on American Standard Testing and Material or British Standard. Analysis of variance and Duncan Multi Range Test MRT were used to distinguish the wood properties and discriminant analysis for classifying wood quality. The study concluded some conclusions. (1) Interaction of age classes, site quality index and stem axial position affect surface defect-free of longitudinal drilling. (2a) Interaction of age classes and site quality index affect the proportion of heart-wood , the growth ring dimension, extractive content, and wood moulding and turning. (2b) Interaction of site quality index and stem axial position affects cleavage strength and wood turning properties. (3a) Age class affects rays proportion, fiber proportion, wood specific gravity and radial shrinkage. (3b) Site quality index affects vessel proportion, parenchyma proportion , specific gravity, tangential shrinkage, compression strength parallel to grain, shear strength, and wood hardness. (4) Interaction of age class IV, site quality index 3.5 and butt stem position produces the highest wood quality of 2.08, otherwise the interaction of age class V, site quality index 3 and upper stem position resulted the lowest wood grade of 2.79. (5a) Interaction of age classes V and site quality index 3.5 produced the highest wood quality of 2,12 and interaction age classes III and site quality index 4.5 resulted the lowest wood rank of 2.79. (5b) Interaction of age class IV and butt stem position produced the highest wood quality of 2.29 and interaction of age classes V and upper stem position resulted the lowest grade of 2.67. (5c) Interaction of site quality index of 4 and butt stem position produced the highest wood quality of 2.27, and interactions of site quality index of 4.5 and upper stem position produces the lowest quality of 2.71. (6a) Age classes V , IV and III produced wood quality class of 2.29 and 2.42 and 2.50 respectively. (6b) Site quality index of 3.5 , 4 , 4.5 and 3 produced wood quality of 2,33; 2.46; 2.50 and 2.58 respectively. (6c) The butt, middle and upper part of stem produced quality timber of 2.37 and 2.41 and 2.46 respectively

Kata Kunci : Umur, Bonita, Posisi aksial batang, Sifat-sifat kayu, Kualitas kayu