窒素施肥曲線を用いた切り花ギクの養液栽培

Abstract

A cut flower production of chrysanthemum cv. Shuhouno-chikara (standard type of cut flower) was investigated using the method of supplying nitrogen along a standard nitrogen application curve. The standard nitrogen application curve (1.0-fold) had been determined in a previous study to modify the rate of nitrogen absorption and growth curves.Rooted cuttings of chrysanthemum were transplanted into a hydroponic apparatus in a plastic film green house on 30 th July 1992. The terminal shoots were pinched above the fifth node on 23 rd July and the plants' subsequent growth was trained to two lateral shoots for cut flowers. The cut flowers were harvested on 9 th November.Experimental plots consisted of ; three plots, where nitrogen was supplied along the 1.0, 0.8 and 0.6-fold nitrogen application curves, and 100 ppm N plot in which nitrogen concentration in the culture solution was adjusted weekly to 100 ppm.Plants in 1.0 and 0.8-fold plots grew normally and produced good quality cut flowers compared to those in 0.6-fold plot whose quality was poor. Plants in 100 ppm N plot grew vigorously throughout the experiment, and developed excessively large leaves and flower stems for marketable cut flowers.Plants supplied with nitrogen divided weekly along the nitrogen application curves absorbed entirely all the nitrogen during the initial 2 to 3 days, therefore, this was a restrictive method of nitrogen application in hydroponics.