2020 年 64 巻 4 号 p. 201-211
The growth and starch accumulation processes of sago palm with age in the natural forest were investigated in South Sorong, West Papua, Indonesia. The surveyed natural forest seemed to be a nearly pure sago palm forest and have reached the climax forest stage. The sucker density was lower than that of the cultivated garden, and the trunk density (trunks of 0.5 m or more) was almost equal. In addition, the trunk length at the flowering stage was longer than that in the cultivated garden, and the trunk frequency during the flowering to the dying/dead stage was higher. In the natural forest, it was difficult to estimate palm age, thus the number of leaf scars and leaves (No. LS + L) was used as an index of palm age. Until the No. LS + L was about 80 (about 10 m in trunk length), there was almost no increase in the percentages of dry matter and starch in the pith. However, afterward, these percentages and the starch content of the pith increased rapidly. The average starch content at the harvest stage was about 360 kg, but its variation was large among the individuals. The sago palms in the natural forest had lower percentages of dry matter and starch in the pith even at the optimal harvest stage, and the starch productivities per trunk length, fresh weight, and volume were lower than those of the cultivated sago palms.