We investigated the changes in the leaf characteristics and shoot biomass with plant age of ‘sagu baruk’ on Sangihe Island, North Sulawesi, Indonesia. ‘Sagu baruk’ has a long trunk length but its diameter is small and a poor crown development. Therefore, due to the small leaf area per plant (maximum about 90 m2), the biomass production system was inferior. Shoot fresh and dry weights at harvest stage (about 550 kg; 250–300 kg, respectively) were inferior even when compared to the sugar and sago palms, which are the same or a little earlier in the number of years until the optimal harvest stage. Furthermore, in ‘sagu baruk’, the relative proportion of the fibrous tissue at the peripheral part of the pith, which developed with plant age, increased because the trunk diameter was small, and the pith weight ratio in the trunk weight-fresh weight: 72.3%; dry weight: 69.5%-was lower than those of other starch-accumulating palms. Thus, its low biomass production and low pith weight ratio in the trunk weight were considered to be the cause of the low starch productivity per plant (about 90 kg). Although ‘sagu baruk’ has a low starch productivity per plant, it is easy to propagate due to its being a clump palm which can possibly grow under relatively dense condition because of its small trunk diameter. Therefore, it is necessary to study its growth characteristics, biomass production, and starch productivity per area under different planting densities.
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