PROBLEM TO BE SOLVED: To provide a seedling growth method with which can be obtained plant seedling having thick stems, and high productivity from an increased fruit yield from the continued increase in the number of flowers from a low stage to a high stage.SOLUTION: The seedling growth method promotes growth by the irradiation of artificial light on the plant seedlings. For the irradiation of artificial light, irradiation is carried out with blue illumination light and red illumination light using at least a light source other than a fluorescent lamp and glutathione is administered to the plant seedling during seedling growth.SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】定植後に、茎が太く、低段から高段まで継続して花数が増大し、果実の収量増加となる生産性の高い植物苗を得ることが可能な育苗方法が提供する。【解決手段】本発明の育苗方法は、植物苗に人工光を照射して生育を促進させる育苗方法であって、前記人工光の照射として、少なくとも蛍光灯以外の光源を用いた青色照明光および赤色照明光の照射が行われ、育苗期間内に植物苗にグルタチオンを与える。【選択図】なし