盆菊營養與栽培介質理化性適宜值探討

Abstract

Potted chrysanthemum (Chrysanthemum morifolium Ramat) is an important potted flower in Taiwan with approximate 300,000 pots planted each year. However, low-quality products of potted chrysanthemum were frequent found due to improper fertilization in commercial production, and the market value has been markedly affected. For upgrading the quality to increase competitiveness, the present study was conducted to elucidate the relationship between nutrient uptake, physical and chemical properties of growth media, different growth media, nutrient solution and quality of potted chrysanthemum, and to develop a better model for further optimization of nutrient and media management of potted chrysanthemum. An analysis of the relation of nutrient uptake to vegetative growth revealed that there was a significant relationship between the plant growth and weather conditions. Under the condition of the optimum temperature range of 16-24℃, the accumulated duration of sunshine is a key limiting factor contributing to nutrient uptake and vegetative growth of potted chrysanthemum. The growing days of potted chrysanthemum was significantly affected by temperature and duration of sunshine; the growing days for October transplantings was 80 days, and 120 days for November transplantings. The N, P, K concentration ratios of plant tissue were 7.7:1.0:8.2 for October transplantings, and 5.7:1.0:6.7 for November transplantings. Measurements of the plant nutrient concentration showed that the highest nutrient concentration of potted chrysanthemum was potassium next were nitrogen and phosphorus concentration, respectively. Data also revealed that vegetative mass and nutrient uptake for potted chrysanthemum transplanted in October was higher than that of November transplantings. Assessments of optimum physical and chemical properties of growth media for potted chrysanthemum showed that the plant characters were significantly affected by pH, EC, CEC, total porosity, water capacity and water-holding capacity of growth media. Based on crop response, the optimum condition of growing medium were proposed for pH (1:5) at range of 5.0-6.2, EC (1:5) below 2.33 dS/m, CEC 15-35 me/100g, total porosity above 55 %, water capacity above 80 % and water-holding capacity at 40-65 %. Results of analysis of the effects of application concentration and frequency of nutrient solution on potted chrysanthemum confirmed that the optimum N－P－K concentration of nutrient solution at rates of 145~190－25~35－185~240 mg/l before flower formation and 400~500－60~80－370~480 mg/l after flower formation for October transplantings, and 70-15-85 mg/l of N-P-K through the whole growing period for November transplantings. The optimum application frequency of nutrient solution was once per two days and the amount of solution was given at 100 ml per pot at each application

盆菊(Chrysanthemum morifolium Ramat)為國內重要盆花之一，年生產量在30萬盆左右。但由於栽培管理技術不臻成熟，品質普遍不佳，市場價格也深受影響。為提昇盆菊品質及市場競爭力，本研究進行一系列盆菊栽培介質之調配及肥培管理技術相關試驗，擬試驗評估菊花植體養分吸收，探討介質理化性，究明各種配方介質及培養液等對盆菊需肥量與品質之關係，進而確立一套完整的盆菊營養及介質管理模式，作為栽培介質、培養液配方及施肥推薦之依據。 盆菊營養吸收及生長特性關係研究，發現盆菊生長在適溫(16-24℃)條件下，累計日照時數為植體生長量及養分吸收量之主要限制因子。盆菊10月底以前插植者，由於溫度較高及日照時數長，所需生長日數僅約80天，11月以後插植者，生長期間溫度低及日照時數短，需較長之營養生長期，生長日數約120天。盆菊植體養分含量比值10月26日插植者為7.7：1.0：8.2，11月20日插植者則為5.7：1.0：6.7，其吸收量以鉀最高，次為氮，再次為磷。盆菊植體生長量，10月以前插植者較11月以後插植者高約1.5倍。養分吸收量，氮及鉀高約2倍，磷、鈣及鎂則分別高約1.6、1.3及1.4倍。 盆菊栽培介質理化性適宜值之評估，顯示栽培介質pH、EC、CEC、總孔隙度、容水量及保水力等理化性質對盆菊性狀均有不同程度的顯著影響。依據其影響程度界定盆菊栽培介質pH(1：5)、EC(1：5)、CEC、總孔隙度、容水量及保水力之最適範圍，分別為5.0-6.2、2.33 dS/m以下、15-35 cmole/kg、55 %以上、80 % 以上及40-65 %。以上，盆菊栽培介質理化性適宜值範圍，經驗証確實符合盆菊生長要求。 根據盆菊養液配方施用濃度及頻率試驗，得知盆菊最適肥料施用濃度，10月底以前插植者，花芽形成前N─P─K＝145-190─25-35─185-240 mg/l，花芽形成後N─P─K＝400-500─60-80─370-480 mg/l，11月以後插植者，全期N─P─K＝70─15─85 mg/l。最適施肥頻率則為每二天施用一次， 5寸盆每次灌施量為100 ml。