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PERTUMBUHAN POHON JATI UNGGUL NUSANTARA (Tectona grandis L.f.) DAN PENGARUHNYA TERHADAP SIFAT KAYU YANG DIHASILKAN

GUDIWIDAYANTO SAPTO PUTRO, Prof. Dr. Ir. Sri Nugroho Marsoem, M.Agr.Sc; Dr. Joko Sulistyo, S.Hut, M.Sc; Prof. Dr. Ir. Suryo Hardiwinoto, M.Agr.Sc.

2020 | Disertasi | DOKTOR ILMU KEHUTANAN

Jati Unggul Nusantara (JUN) merupakan klon jati hasil pengembangan teknologi pemuliaan pohon untuk mempercepat pertumbuhan. Peningkatan laju pertumbuhan sering diikuti oleh perubahan sifat-sifat kayu yang mengarah pada kurang sesuainya dengan tujuan penggunaan. Penelitian pada tiga klon JUN dan dua kelompok umur dilakukan untuk mengkaji besarnya pengaruh klon, umur pohon dan faktor lingkungan terhadap pertumbuhan JUN dan sifat kayu yang dihasilkan. Rancangan acak lengkap split-plot disusun untuk mempelajari pertumbuhan JUN dan sifat kayu pada akhir pengamatan. Faktor pertama adalah umur pohon yang terdiri dari tegakan umur lima dan delapan tahun. Faktor kedua adalah jenis klon yang terdiri dari klon D14, F35 dan F21. Faktor ketiga adalah posisi kayu pada arah radial berdasarkan lingkaran tahun pohon yang terdiri dari lingkaran tahun pertama sampai lingkaran tahun terakhir. Pengamatan pertumbuhan tinggi dan diameter dilakukan dengan intensitas sampling 50% pada masing-masing klon dengan total individu sampel sebanyak 300 pohon. Pengamatan laju pertumbuhan pertahun dan sifat kayu dilakukan pada tiga individu pohon untuk setiap unit perlakuan, sehingga total digunakan 18 pohon sampel. Analisis data pertumbuhan dan sifat kayu dilakukan dengan analisis varians, dilanjutkan dengan Duncan's multiple range test. Hubungan tinggi dan diameter dianalisis dengan analisis regresi linier, sementara itu hubungan antara laju pertumbuhan dan sifat kayu dianalisis dengan analisis korelasi. Hasil penelitian menunjukkan perbedaan klon dan umur pohon berpengaruh nyata terhadap pertumbuhan tinggi dan diameter batang, proporsi dan dimensi sel serabut, berat jenis kayu, dan proporsi kayu teras pohon. JUN klon D14 memiliki kinerja pertumbuhan yang paling baik dengan pertumbuhan diameter dan tinggi secara berturut-turut 14,60 cm dan 9,80 m pada umur 5 tahun serta 20,50 cm dan 15,20 m pada umur 8 tahun, dan persamaan regresi diameter dan tinggi pohon y= 0,9366x + 6,7366. Fluktuasi curah hujan dan suhu bulanan memiliki korelasi yang kuat terhadap laju pertumbuhan. Klon D14 umur delapan tahun menghasilkan sifat kayu terbaik untuk tujuan konstruksi ringan dan furnitur dengan proporsi kayu teras 49%, dimensi serat (panjang 1,111mm, tebal dinding 3,277 um, diameter 16,995 um, dan diameter lumen 10,523 um), proporsi sel (serabut 60,50%, jari-jari 20,29%, parenkim longitudinal 8,64%, dan pembuluh 10,523%) dan berat jenis (kayu segar 0,54, kayu kering angin 0,598. Distribusi sifat kayu pada arah radial mengindikasikan masih dalam periode kayu juvenil.

Jati Unggul Nusantara (JUN) is a teak clone resulting from the development of tree breeding technology to accelerate growth. The increase in tree growth rate is often followed by changes in the nature of the wood which leads to less suitability for the intended use. Research on three JUN clones and two age groups was conducted to, assess the effect of clones, tree age, and environmental factors on JUN growth and the nature of the wood produced. The split-plot completely randomized design was arranged to study the JUN growth and wood properties at the end of the observation. The first factor was the age of the tree which consists of stands of five and eight years old. The second factor was the type of clone consisting of clones D14, F35, and F21. The third factor was the position of the wood in the radial direction based on the tree ring which consists of the first tree ring to the last tree ring. Height and diameter growth observations were carried out with 50% sampling intensity in each clone with a total sample of 300 trees. The annual growth rate and wood nature were observed for three individual trees for each treatment unit so that a total of 18 sample trees were used. Data analysis of the growth and wood properties was done by the analysis of variance. For significant factors, further tests were performed with Duncan's multiple range test. The relationship of height and diameter was analyzed by linear regression analysis, while the relationship between growth rate and wood properties was analyzed by Pearson correlation analysis. The results showed that the differences in clones and tree age significantly affected the growth of stem height and diameter, fiber cell proportions and dimensions, specific gravity, and the proportion of tree heartwood. JUN clone D14 had the best growth performance with diameter and height growth respectively 14.60 cm and 9.80 m at the age of 5 years and 20.50 cm and 15.20 m at the age of eight years, and the diameter and tree height regression equation y = 0.9366x + 6.7366. Fluctuations in monthly rainfall and temperatures had a strong correlation with the rate of growth and the nature of the wood produced. The growth rate between tree individuals significantly influenced the nature of the wood produced. Clone D14 at eight years old produced the best wood nature for light construction and furniture purposes with a proportion of heartwood 49%, fiber dimensions (length 1.111mm, wall thickness 3.277 um, diameter 16.995 um, and lumen diameter 10.523 um), cell proportion (fiber 60.50%, ray 20.29%, longitudinal parenchyma 8.64%, and vessels 10.523%) and specific gravity (greenwood 0.540 and air-dry wood 0.598). The distribution of wood nature in the radial direction was more related to the increasing age of the trees, thus indicating that it was still in the juvenile period.

Kata Kunci : jati unggul, laju pertumbuhan, proporsi dan dimensi sel, berat jenis/superior teak, growth rate, cell dimension and proportion, specific gravity

  1. S3-2020-373891-abstract.pdf  
  2. S3-2020-373891-bibliography.pdf  
  3. S3-2020-373891-tableofcontent.pdf  
  4. S3-2020-373891-title.pdf