生長抑制劑、硝酸鈣以及摘心對聖誕紅盆花品質之影響

Abstract

本試驗以聖誕紅商業栽培品種‘倍利’（‘Pepride’）、‘自由’（‘Eckespoint Freedom’）與‘聖誕玫瑰’（‘Winter Rose’）插穗為試驗材料，以探討不同濃度之生長抑制劑、硝酸鈣及5種摘心方式處理對聖誕紅盆花品質之影響。 隨著paclobutrazol處理濃度增加，此三品種聖誕紅株高、乾鮮重、枝梢生長量、葉面積皆有降低之趨勢，而花期則有提早之現象。‘倍利’、‘自由’與‘聖誕玫瑰’在80 ppm處理濃度下，株高只有對照組的50％左右，到花日數則提早3∼16天。‘聖誕玫瑰’對paclobutrazol較‘倍利’與‘自由’敏感，paclobutrazol處理濃度越高，葉片向內捲曲越嚴重，但對苞葉Lab值與葉綠素含量有促進之效果。隨著paclobutrazol處理濃度增加，植株含氮量亦有提高之現象，其中以‘倍利’ 80 ppm處理濃度下含氮量3.3％最高。且營養生長期植株氮素含量較高，轉色期後隨之降低，至盛花期時其含氮量最低。植株中大量元素的含量，會隨paclobutrazol濃度提高而增加，微量元素含量則無固定之趨勢。 隨著硝酸鈣處理濃度的增加，‘倍利’、‘自由’與‘聖誕玫瑰’之株高、枝梢生長量、花序直徑與地上部鮮重等均會隨之增加， ‘倍利’以 300 ppm處理之植株高為16.83 cm較未處理硝酸鈣者11.67 cm多了5 cm左右，但以400 ppm Ca(NO3)2 處理時，‘倍利’之株高與地上部鮮重則呈現下降趨勢。‘倍利’苞葉之Lab值會隨硝酸鈣濃度增加而增加，而‘自由’苞葉之明亮度則會隨之下降。以Ca(NO3)2處理時可促進‘自由’與‘聖誕玫瑰’在盛花期時之葉片葉綠素含量，但對植株之碳水化合物含量則無明顯之影響。 ‘倍利’、‘自由’與‘聖誕玫瑰’以弱摘心後立即去除葉片葉柄之處理方式（D與E），可獲得較矮之植株與較多的花序數目，而單獨弱摘心或弱摘心後待側芽萌發1 cm去除葉片葉柄之處理（A、B與C），其植株側枝較長但數量較少，而葉柄的去留對植株之影響差異不大。‘聖誕玫瑰’ 以弱摘心後立即去除葉片葉柄後，其株高為22.43 cm，花序數目為5.33個，較單獨弱摘心矮4 cm並多了2個花序。而不同摘心處理方式對聖誕紅植株葉綠素與碳水化合物含量之影響則無明顯之差異。

Euphorbia publcherrima Willd. ex ‘Pepride', ‘Eckespoint Freedom' and ‘Winter Rose' were used in this study. The objective is to investigate the effect of growth retardant, Ca(NO3)2 treatment and pinching types on the quality of poinsettias. The plant height, dry weight, fresh weight, growth of shoots and leaves area of three cultivar were decreased along with the concentration of paclobutrazol, but anthesis were apeared earlier. When ‘Pepride', ‘Eckespoint Freedom' and ‘Winter Rose' were treated with 80 ppm resulted in plant were half height of controlled plant and anthesis were apeared earlier about 3~16 days. ‘Winter Rose' were more sensitive to paclobutrazol than ‘Pepride' and ‘Eckespoint Freedom'. The leaves of ‘Winter Rose' curled seriously but the values of L, a, b and chlorophyll content would increase along with the concentration. The macroelements content of nitrogen, phosphorus, potassium, calcium and magnesium of three cultivars would increase with treated concentration. Three cultivar of poinsettia were treated with different Ca(NO3)2 concentration, on which plant height, growth of shoots, infloresence diameter and fresh weight would increase along with the concentration. The height of ‘Pepride' treated with Ca(NO3)2 300 ppm was 16.83 cm more than 0 ppm 5 cm. However the plant height and fresh weight of ‘Pepride' would decrease at 400 ppm. The values of L, a, b of ‘Pepride' bracts would increase with concentration, but the brightness of ‘Eckespoint Freedom' bracts decreased. Nevertherless increased the chlorophyll content of ‘Eckespoint Freedom' and ‘Winter Rose' at anthesis, but had no effects on the carbohydrate content of poinsettias. ‘Pepride', ‘Eckespoint Freedom' and ‘Winter Rose' were treated with soft pinching with leaf and petiole removal (D and E), resulted in shortening the plant height but had more 1~2 infloresences. Only soft pinching or soft pinching with leaf and petiole removal after lateral shoot 1 cm long (A, B and C) could increase the long of lateral shoots but the number of lateral shoots decreased. ‘Winter Rose' were treated with soft pinching with leaf and petiole removal the plant height was 22.43 cm and the number of infloresences was 5.33. Three cultivars of poinsettia were treated with different pinching types had no effects on the chlorophyll and carbohydrate content.