PROBLEM TO BE SOLVED: To provide a quality-improving agent which improves appearance of cut flowers, extends their life, is safe, and is of low cost, and a method for quality improvement of cut flowers.SOLUTION: As an effective component of a quality improving agent for cut flowers, nigerooligosaccharide is contained in the agent. This quality- improving agent is diluted and an aqueous solution containing the nigerooligosaccharide is prepared, and the quality improving agent is brought into contact with cut flowers, by means of either soaking cut faces of cut the cut flowers or spraying the agent solution to the flowers. By these treatments, the quality improvement agent gives increased number of blooming flowers, increase in size and weight of flower, increase the length of flower cluster, and extention of life of the cut flowers. The quality-improving agent and the quality-improving method are particularly faborably used for cut flowers of Scrophulariaceae and Gentianaceae.COPYRIGHT: (C)2002,JPO【課題】 切り花の見栄えを良くすると共に、延命効果をも有し、かつ安全性が高く、安価な、切り花の品質改良剤及び品質改良方法を提供する。【解決手段】 切り花の品質改良剤の有効成分としてニゲロオリゴ糖を含有させる。この品質改良剤を希釈して、ニゲロオリゴ糖を含有する水溶液を調製し、この水溶液に切り花の切り口を浸漬させるか、又は前記水溶液を切り花に噴霧することにより、前記水溶液を切り花に接触させる。これにより、切り花の開花数の増大、花のサイズ及び質量の増大、及び花穂の伸長効果を付与すると共に、切り花の延命効果を付与する。この切り花の品質改良剤及び品質改良方法は、ゴマノハグサ科又はリンドウ科に属する切り花に特に好ましく適用される。
