The Effects of Nutriments and Light Quality on the Leaf Coloration of Croton (Codiaeum variegatum Blume)

Abstract

本研究使用變葉木品種龜甲紅 cv. Caribben Star和大鼈甲 cv. Andreanum 為材料。在營養素過量試驗上，分別施用多量的NH4NO3、NaHPO4、KCl、CaCl2、MgSO4、FeSO4、H3BO3來處理。缺乏試驗則分別缺少氮、磷、鉀、鈣、鐵的方式處理。色光試驗使用紅色、綠色、藍色等有色玻璃紙遮蓋下栽培變葉木。 多量營養素處理的結果；多氮使葉片綠色部分加深轉變為墨綠色，紅色部分也更紅，多鈣時葉片綠色部位變為褐綠色，彩色部位較紅。多鉀和多磷均使葉綠素減少，擴大彩色部位面積。缺營養素處理，在缺鈣葉片上，綠色部位易出現黃色斑點，缺磷葉片彩色部位加紅，缺氮可使整葉變淡綠色。 色光處理之結果，如用紅色玻璃紙遮蓋，葉色變淡，尤其彩色部位無紅色出現，而呈淡乳黃色。藍色玻璃紙下，葉色較濃較紅。綠色玻璃紙下，則彩色部位面積加大並呈金黃色。品種間以龍甲紅的反應變化較顯著。The objective of this study was to investigate the respective effects of over supply nutriment deficiency and light quality on leaf color development of Croton. Two cultivars;“Caribbean Star”and “Andreanum” were used in the experiments. The Crotons were planted in 6" pot for over supply nutriments and light quality test, others were used with water culture for nutrient deficient test. The plants were treated with excess of N, P, K, Ca, Mg, Fe, B and deficiency of N, P, K, Fe nutriments. The light quality test were covered with red, blue and green cellophane paper. The results showed that over supply N nutriment affected green color of leaves more deeper than others, and sometimes made a little more reddish on color-portion of leaves. Color of green-portion of leaves turn to brown-green and color-portion turn to red~orange red with excessive Ca treatment. Over supply K and Mg treatments reduced green color and made bigger color-portion. Color of the leaves Changed slightly with treatments of other nutriments in excess. Yellow spots appeared on leaves earlier in deficient Ca treatment plants than those treatments with other nutriments. The color of color-portion was changed to red in deficient P treatment. Poor growth but slight change of color was observed if inadequate amount of N, K, Fe unsupplied during summer. Color of green-portion on leaves became viridescent and color-portion turn to cream yellow with red light treatment. The area of color-portion on leaves became bigger and more golden yellow under green light. Color of the leaves changed slightly with blue light treatment