Changes in Nutrient Contents in Pith of Sago Palm (Metroxylon sagu Rottb.) Suckers during Storage and Effects of Storage Conditions on Subsequent Growth during Nursery Period

摘要

The present study evaluated the survival rate and the growth performance of sago palm suckers during the early establishment in response to storage conditions (shaded and unshaded conditions) prior to the nursery period. Moreover, changes in the contents of macronutrients (N, P, K, Ca, and Mg) as well as nonstructural carbohydrates in the pith were also elucidated. Storage periods of 0, 3, 7, 15, and 25 days were used. Storage of the collected suckers prior to the nursery period reduced their freshness due to the reduction of the moisture content. The suckers stored under shaded conditions lost less weight than those stored under unshaded conditions, especially during the 3- to 15- day period after storage (DAS) and at 25 DAS, they showed a similarweight loss. While the pith dry matter percentage and the contents of macronutrients as well as total sugar in the pith increased with the prolongation of the storage period, the content of starch decreased steadily. The changes in those parameters between the two storage methods in each storage period were not significantly different in most cases. The contents of macronutrients, in general, were maximum mainly at 7 and 15 DAS. They decreased thereafter when the period was extended to 15 or 25 days. Direct nursery transfer resulted in a survival rate of 87.5 % and the rate decreased with the prolongation of the storage period, regardless of the storage methods. A long storage period (25 days) considerably reduced the sucker survival rate below 20 %, even when the suckers were kept under shaded conditions and none of them was able to survive when they were stored under unshaded conditions. The survival rate of sago palm suckers during the nursery period could be enhanced by using freshly prepared suckers. If the suckers need to be stored for any reasons, placement under shaded conditions for less than a one week is recommended.