Sifat Anatomi dan Penentuan Titik Demarkasi Kayu Juvenil dan Kayu Dewasa pada Tiga Kualitas Mutu Jati

Abstract

Jati (Tectona grandis Linn. f) merupakan salah satu jenis kayu paling diminati di Indonesia. Optimalisasi pemanfaatan kayu jati ditentukan oleh pemahaman kayu juvenil serta batas peralihannya ke kayu dewasa. Penelitian ini bertujuan menentukan titik transisi kayu juvenil ke kayu dewasa pada tiga kualitas kayu jati (jati hara, jati lokal, dan jati industri). Penelitian meliputi penentuan proporsi kayu teras, kerapatan, analisis anatomi, serta penentuan titik demarkasi kayu juvenil dan dewasa melalui pendekatan panjang serat dan sudut mikrofibril (MFA) dari empulur sampai kulit. Hasil penelitian menunjukkan bahwa persentase kayu teras dari jati hara sebesar 91,05%, jati lokal 84,42%, dan jati industri 56,59%. Nilai kerapatan rata-rata berturut-turut sebesar 0,79 g/cm³; 0,70 g/cm³; dan 0,75 g/cm³. Secara anatomi, ketiga kualitas jati memiliki karakteristik relatif sama. Perbedaannya terutama terlihat dari warna penampang kayu dan diameter pori-pori kayu. Analisis panjang serat masing masing mutu kualitas kayu hara, lokal, dan industri menunjukkan kayu dewasa mulai terbentuk pada segmen 15, segmen 22, dan segmen 20. Sementara analisis MFA berturut-turut menunjukkan kayu dewasa mulai terbentuk pada segmen 17, segmen 24, dan segmen 22.

Teak (Tectona grandis Linn. f) is one of the most popular use of wood in Indonesia. The optimal utilization of teak wood is determined by an understanding of juvenile wood and its transition point to mature wood. This research aims to determine the transition point from juvenile to mature wood across three teak wood qualities (hara teak, local teak, and industrial teak). The research includes the determination of the proportion of heartwood, wood density, anatomical analysis, and identification of the demarcation point using fiber length and microfibril angle from the pith to the bark. The results showed that the percentage of heartwood was 91.05% for Hara, 84.42% for local, and 56.59% for industrial. The average density values were 0.79 g/cm³, 0.70 g/cm³, and 0.75 g/cm³, respectively. Anatomically, the three teak qualities share relatively similar characteristics; differences can be observed in the wood cross-section color and pore diameter. Analysis of fiber length for each quality grade hara, local, and industrial shows that mature wood begins to form in segments 15, 22, and 20. Subsequently, MFA analysis indicates that mature wood begins to form in segments 17, 24, and 22.