Abstract
In this study, the authors investigated flower and seed production and the status of inflorescence/rhizome-cut culms for the dwarf bamboo Sasa veitchii var. hirsuta in order to clarify differences in the culm dying-out process between inflorescence-cut culms and control culms in mass flowering and subsequent flowering. The results revealed that the seed set ratio and the dead-to-total-culm ratio (known as the dead culm ratio) were small in the first flowering, and that the seed set ratio was larger and the dead culm ratio was 95% for control culms in the second flowering of the mass-flowering event. Culm death was not observed in the first flowering, and the dead culm ratio was 25% for inflorescence-cut culms in the second flowering of the mass-flowering event. The similar tendency was observed for rhizome-cut culms and rhizome- and inflorescence-cut culms. The seed set ratio was larger than that observed in the first flowering and the dead culm ratio was 93% for rhizome-cut culms in the second flowering of the mass-flowering event. For rhizome-and inflorescence-cut culms, the dead culm ratio was 53% in the second flowering of the mass-flowering event. Culms that did not die in the mass-flowering event flowered and died the following year. These results suggest that inflorescence cutting makes the dead culm ratio smaller than that observed in natural conditions in mass flowering. It was also observed that inflorescence-cut culms finally die the year after mass flowering, and that a high seed set ratio causes marked culm death in natural conditions.
