Studies on the nutrient and optimum physical, chemical properties of growth media for potted chrysanthemum

• Main Authors: Chiu-Shyoung Lo, 羅秋雄
• Other Authors: Yin-Po Wang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/11538623300368889286

博士 === 國立中興大學 === 土壤環境科學系 === 89 === 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