遮光、生長抑制劑及氮肥對紅葉粗肋草生育之影響

紅葉色系粗肋草為台灣重要的盆花之一，目前對於紅葉色系粗肋草的栽培研究尚少。本研究探討遮光程度、植物生長抑制劑應用、氮素型態及總氮濃度對紅葉色系粗肋草‘極光’ 和‘亞曼尼’生長之影響，期建立優良栽培條件，以加速植株生育速率並提高盆栽品質。供試二品種分別在80%和70%遮光處理，有最多側芽數量和澱粉含量。‘極光’之地上部及地下部鮮、乾重在遮光60%~80%表現最佳；‘亞曼尼’在70%遮光處理表現最佳。‘極光’之葉綠素含量隨著遮光程度提高而上升；而‘亞曼尼’則以遮光60%及90%處理最高。兩品種的葉片色澤以遮光80%處理為最佳。隨著巴克素(Paclobutrazol)施用濃度提高，‘極光’節間長度隨之縮短，葉綠素含量以1 mg．L-1澆灌2次處理最高。‘亞曼尼’以葉面或澆灌施用2次，葉柄長度皆隨著施用濃度增加而縮短，葉綠素含量隨著澆灌濃度提高而上升。兩個品種栽培在NH4+ : NO3-為3:7的條件下，有較佳的葉長、側芽數量、地上部鮮重、總葉綠素含量及植體總氮含量，根部活性皆以NH4+ : NO3- = 0:10為最高。兩品種在總氮濃度7.5 mMol．L-1處理下，皆有最佳的地上部和地下部鮮重、乾重、總葉綠素含量及植體總氮含量。植體的醣類及澱粉含量皆隨著總氮濃度的提高而上升；根部活性則隨之下降。綜合以上結果，‘極光’在80%遮光程度，搭配NH4+:NO3-=3:7及總氮濃度7.5 mMol．L-1的條件下，另外澆灌1次4 mg．L-1 Paclobutrazol，可以產生較佳的植株品質。‘亞曼尼’ 在70%遮光程度，搭配NH4+:NO3-=3:7及總氮濃度7.5 mMol．L-1的條件下，另以葉面施用20 mg．L-1 Paclobutrazol，植株具有較佳的生長勢。

關鍵字

遮光；氮素型態；總氮濃度；巴克素；葉綠素含量；葉柄長度

並列摘要

The red-leaf type of aglaonema is ne of the important foliage plants in Taiwan. Nowadays, there is insufficient information in the aglaonema industry . Therefore, the effects of shading, the concentration and method of paclobutrazol application, the type of nitrogen and the total concentration of nitrogen were investigated in aglaonema cultivars : ‘Siam Aurora’ and ‘Anyamanee’. Moreover, to establish the optimum growing conditions could accelerate growth and improve quality in potted aglaonema. Plants were grown under four different shading conditions. Both of ‘Siam Aurora’ and ‘Anyamanee’ had the highest number of lateral buds and starch content when plant grown at 80% and 70% shading, respectively. The maximum shoot and root fresh weight, and dry weight were grown under 60% - 80% shading for ‘Siam Aurora’ and 70% of shading for ‘Anyamanee’. Chlorophyll content was increased with increasing shading level for ‘Siam Aurora’ , 60% and 90% shading for ‘Anyamanee’. Both cultivars have the best leaf color at 80% shading. Internode length decreased as the degree of paclobutrazol concentration increased for ‘Siam Aurora’. For chlorophyll content, the optimum concentration and times of application of paclobutrazol was 1 mg．L-1 drenched twice. The petiole length of ‘Anyamanee’ decreased with increasing concentration of paclobutrazol, applied twice either as spray and drench. The chlorophyll content increased as concentration of paclobutrazol increased. In both cultivars, the optimum ratio of NH4+:NO3- for leaf length, number of lateral buds, shoot fresh weight, chlorophyll content, and N content was 3:7; whereas a fertilizer of 0:10 NH4+:NO3- ratio has the highest root activity. The optimum concentration of N for the fresh and dry weight of shoots and roots, chlorophyll content, and N content was 7.5 mMol．L-1. Total soluble solids and starch increased, and root activity decreased as the concentration of nitrogen increased. In conclusion, the best quality of aglaonema ‘Siam Aurora’ and ‘Anyamanee’ were produced under 80% and 70% shading, respectively. For both cultivars, the optimum concentration of N was 7.5 mMol．L-1 with NH4+:NO3- ratio of 3:7. The optimum concentration and application of paclobutrazol was drenched twice at the concentration of 1 mg．L-1 for ‘Siam Aurora’ and sprayed twice at the concentration of 20 mg．L-1 for ‘Anyamanee’.