Growth characteristics and starch productivity of three varieties of sago palm (Metroxylon sagu Rottb.) in Southeast Sulawesi, Indonesia.

摘要

We compared the growth characteristics and starch productivity among three major sago varieties (folk varieties), namely Molat (spineless), Tuni (spined), and Rotan (spined), grown near Kendari, Southeast Sulawesi Province, Indonesia. Growth characteristics of the three varieties were compared in relation to years after trunk formation (ATF). All the three varieties reached the trunk formation stage at 3 to 4 years after sucker planting or emergence. However, Molat and Tuni reached the flowering stage at 8 to 10 years ATF, whereas Rotan reached the flowering stage at 6 to 7 years ATF. The trunk length and trunk weight increased with increasing years ATF, and the trunk elongation rates were almost the same in the three varieties (1.0-1.1 m/year). However, the increase in trunk weight per year ATF differed markedly among the three varieties as follows; Molat (233 kg), Tuni (181 kg), and Rotan (90 kg). At the harvesting stage, the average trunk weight was 1823 kg in Molat, 1399 kg in Tuni, and 566 kg in Rotan. On a dry weight basis, the starch percentage in the pith increased from 1 to 3 or 4 years ATF in Rotan and from 3 to 7 or 8 years ATF in Molat and Tuni. In all the varieties, the starch percentage reached 60-70%. Starch accumulation began in the first year ATF in Rotan, but began at approximately at 4 years ATF in Molat and Tuni. Once starch accumulation had begun, it continued at a constant rate in all the varieties (81, 62, and 28 kg/palm/year in Molat, Tuni, and Rotan, respectively). At the harvesting stage, the average starch yield was 425 kg in Molat, 305 kg in Tuni, and 142 kg in Rotan. These differences resulted from differences in the trunk (pith) weight.