氮素濃度與型態對綠巨人白鶴芋生長之影響

Effects of Nitrogen Concentration and Form on Growth of Spathiphyllum 'Sensation'

將可見葉數6～7片之綠巨人白鶴芋組織培養苗以椰纖為主要介質栽培，研究0～32mM氮素濃度與銨態氮、硝酸態氮及尿素等氮源對其生長之影響。結果顯示不施氮肥處理之植株葉片黃化且葉數幾乎無增加。氮素濃度略增至4mM則植株生長及葉片磷鉀含量顯著增加；氮素8mM處理之植株具最大葉面積，品質亦最佳。32mM氮素處理則葉面積不增反減、葉片含鈣量降低且增加葉緣壞疽、皺縮、黃化之葉數。以銨態氮處理於椰纖生長之值株具較多落葉與壞疽葉數，介質拌入9g/L苦土石灰則減少葉緣壞疽數目。施用硝酸態氮或尿素態氮之植株落葉數及葉緣壞疽數較少、品質較佳。

Effects of nitrogen concentration and form (nitrate, urea and ammonium-N) were studied through the growth of Spathiphyllum 'Sensation' grown in coir dust-bused medium. The optimum nitrogen level was proposed lobe 8mM as measured by maximum leaf urea, shoot and root dry weights. An increased nitrogen level up to 32mM resulted in a more chlorophyll content, but also in more puckered leaves, necrosis and chlorotic spots. As nitrogen level increased, leaf N contents were increased, while leaf Ca content decreased. Leaf P and K contents increase us nitrogen level increase from 0 to 8mM, and these contents remained approximately constant from 8 to 32mM N levels. The best quality Spathiphyllum were produced with NO3-N or area-N sources, and the poorest with NH4(superscript +)-N. Plants treated with NH1(superscript +)-N resulted in more necrotic leaves, while the supplement of 9g/L dolomite in the coir dust-bused medium could alleviate the foliar necrotic symptoms.