Paclobutrazol及Uniconazole對大王仙丹花盆花生育及開花之影響

Effect of Paclobutrazol and Uniconazole on Growth and Flowering of Ixora duffii ‘King Ixora’ as Potted Plant

本試驗以扦插發根後6月齡的大王仙丹花盆栽為材料，試驗不同濃度的Paclobutrazol或Uniconazole對植株生育、開花及盆花品質的影響。試驗濃度（mg a.i.／pot）分別為：Paclobutrazol：0，18.75，25，31.25，及37.5；Uniconazole：0，2.5，3.75，5及6.25。結果顯示，所有供試濃度均可有效抑制株高達50%至57%，濃度愈高，抑制效果愈明顯；植株經此兩種矮化劑處理後，葉片較小、花序直徑較小，但對於每株花序數及每花序小花數則影響不大，故盆花品質明顯獲得改善，且達可銷售品質。施用Paclobutrazol或Uniconazole均可使大王仙丹花提早開花，前者於施用後4-4.5個月開花，較未處理者提早約43-75天，依季節而異；後者於施藥後約2個月開花，較未處理者提早約34-37天。Paclobutrazol及Uniconazole應可用於大王仙丹花之花期調節。 One single-drench application of Paclobutrazol and Uniconazole was applied to Ixora duffii ‘King Ixora’ at the dose (mg a.i./pot) of 0, 18.75, 25, 31.25, 37.5 and 0, 2.5, 3.75, 5, 6.25 respectively to determine optimal concentration for potted plant height control and ornamental quality improvement. Both chemicals reduced plant height and inflorescence diameter compared with untreated ones, but the number of inflorescence per plant and floret number per inflorescence were not affected. The performance of potted flowering plant was greatly improved. Regardless of application rate, Paclobutrazol reduced the time to flowering about 43 to 75 days, depending on the season; and the time was reduced about 34-37 days by Uniconazole. It is possible to regulate flowering of Ixora duffii ‘King Ixora’ with Paclobutrazol or Uniconazole.