作者：陳俊位　戴振洋　蔡宜峰

　　 本試驗目的在探討硝酸態氮和銨態氮不同比例液肥施用對甘藍穴盤苗生長與品質之影響效果。由試驗結果顯示，不同型態比例的氮肥施用，於不同生育日數調查穴盤苗園藝性狀時發現，在播種後第 18 日最大葉寬以 NO₃/NH₄-N 比例 (0/90) 處理最差，且與其他處理達顯著性差異。在播種後第 22 天的莖高、葉面積及地上部乾重，以 90/0 處理者表現最佳。在播種後第 26 日的莖高仍以 90/0 處理者表現最好，與 30/60 處理者達顯著性差異。在播種後第 30 日，處理間的園藝性狀以 90/0 處理者整體表現最佳，而以 30/60 處理者的園藝性狀表現最差。其中以 90/0 處理者之乾物重，顯著優於 30/60 及 0/90 處理者。在壯苗指數或絕對生長速率 G 值分析上，以 90/0 處理者最佳，而以 30/60 處理者甘藍穴盤苗品質最差。在播種後第 22 日及第 26 日取甘藍穴盤苗介質進行 pH 值及 EC 值的分析，結果發現，施用 NO₃-N 的比例較高 (90/0) 者，在播種後第 26 日較第 22 天時， pH 值有提高的趨勢。而 NH₄-N 的比例高 (0/90) 者 pH 值維持較穩定。而在病害調查上，露菌病的發生以硝酸態氮鹽含量高者，罹病率高於其它處理者，而以未施肥處理者最低。立枯病在人工接種情形下，初期以硝酸態氮鹽含量高者罹病率高，後期則以銨態氮鹽含量高者罹病率高，顯示病害發生與肥料供應有極大關聯。綜合以上試驗結果， NO₃/NH₄-N 比例 60/30 顯然是較適用於甘藍幼苗栽培之肥料處理。

關鍵字： 甘藍、穴盤苗、氮肥。

　　 The purpose of this research was to assess the effects of the different forms of nitrogen fertilizers used on the growth of cabbage in seedling stage of plug. The experiment was conducted with NH4-N and/or NO3-N fertilizers in different ratio to spray on the cabbage seedlings. Results showed that on the horticulture characters of cabbage seedlings using various nitrogen-form fertilizers could cause different effects. After nitrogen fertilizer was sprayed, the treatment of nitrate (NO3) / ammonium-nitrogen (NH4-N) ratio at 0/90 was worse on leaf width in 1.2 cm than the other treatments at 18th days after sowing recorded. At 22nd days, the treatment of NO3/NH4-N ratio at 90/0 had the best effect on the stem height (2.4 cm), leaf area (5.4 cm2) and shoot dry weight (31mg). At 26th days, the NO3/NH4-N ratio at 90/0 had significant difference on the plant height (2.8 cm) than the 30/60 ratio (2.4 cm). At 30th days, the treatment with NO3/NH4-N ratio at 90/0 had the best effect on the horticultural characters, but the 30/60 ratio was the worst treatment. On the quality of plug seedling, we found the treatment with NO3/NH4-N (90/0) ratio had the best effect on the seedling index (0.0296) and G value (3.67), but the worst one was the NO3/NH4-N (30/60) ratio treatment. At 22nd and 26th day, analysis of the values of media EC and pH, the treatment with NO3/NH4-N (90/0) ratio could increase the pH values. The treatment with NO3/NH4-N (0/90) ratio could maintain the pH values. On the identification of cabbage seedling disease, the ammonium nitrate fertilizer would ehance the downy mildew disease occurred. On the seedling blight disease observation, after artificial inoculation of the pathogen (Rhizoctonia solani AG4) into the peat moss, the nitrate fertilizer treatment had more infected rate on the primary growing stage, but the ammonium nitrate treatment had more infected rate at later stage. In summary, the NO3/NH4-N fertilizer ratio at 60/30 was the best suitable fertilizer, which could be used on the cabbage seedling production.

Key words: cabbage, plug seedling, nitrogen fertilizer.