Causes of Low Viability and Techniques to Improve Germination of Sago (Metroxylon sagu Rottb.) Seeds

  • Eufemio T. Rasco, Jr. University of the Philippines Mindanao
  • Katherine A. Cutab University of the Philippines Mindanao

Abstract

The cultivation of sago, a species of palm growing in the wild in Mindanao and known for its high starch yield, is constrained by its low propagation rate.  Seed propagation, though desirable, is difficult with sago because it tends to produce seedless or parthenocarpic fruits and its seeds have a low germination. To address this problem, we studied the cause of seedlessness and poor germination of sago fruits and explored hydro-priming as a way of mitigating poor germination. Confirming the result of previous studies, six fruit lots of sago, involving a total of 18,566 fruits collected from four towns and three provinces in Mindanao, Philippines, showed a consistently high incidence of seedlessness, with only 504 (2.7%) of the fruits bearing seeds. The biggest lot (7,630 fruits) was 100 per cent seedless. Among fruits with seeds, studies of the effects of hydro-priming (cycles of soaking and drying) and water replacement during soaking treatments show that only the hydro-priming treatment has a significant effect on germination and incidence of normal seedlings. The highest germination percentage of 36.7% was obtained from seeds subjected to two cycles of hydro-priming without water replacement after 125 days. The control (continuous soaking) had only 8.3% germination. Likewise, the highest percent of normal seedlings (31.7%) was obtained with two cycles of hydro-priming without water replacement. The control had only 1.67% normal seedlings. The present studies support the following conclusions: (a) parthenocarpic fruit development is common among the sago palms studied, and (b) seed germination and production of normal seedlings are enhanced by hydro-priming without water replacement. The first conclusion is a confirmation of similar reports in literature, while the second conclusion is unique for this study.

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