2021 Volume 65 Issue 1 Pages 17-28
The biomass of sago palms, growing in the natural forest of South Sorong, West Papua, Indonesia, was measured by fresh and dry weights, and the change in the biomass production in each organ/part with age was examined, using the number of leaf scars and leaves as an index of palm age (a total of 16 plants with 19–145 number of leaf scars and leaves). The biomass increased exponentially after trunk formation, especially after attaining 80 leaf scars and leaves and the fresh and dry weights of the above-ground part (shoot) at the optimal harvest stage (from bolting to the emergence of the inflorescence stage) were 3200–3700 kg and 1030–1230 kg, respectively. The trunk mainly contributed to the increase in the shoot biomass, and the leaf contribution was small. With increasing palm age, the ratio of leaves—mainly the petiole and leaf sheath—in the shoot biomass decreased, while that of trunk, mainly pith, increased. The fresh and dry weight ratios of the pith at the harvest stage to the shoot weight were 66% and 57%, respectively, and 80% and 71% to the lower trunk weight, respectively. Sago palms in the natural forest tended to have a lower dry matter percentage in the pith, a higher ratio of bark and a lower ratio of pith in the dry weight at the harvest stage than did the sago palms under cultivation conditions.