Using light to improve ornamental plant propagation in controlled environments

Abstract

Light-emitting diodes (LEDs) can provide different spectrum and spectral combinations. This thesis investigated the effects of different monochromatic light spectra on seed germination of some commercially important ornamental plants, explored optimal light recipes for gerbera seedling production, and investigated the effects of dynamic red (R) and blue (B) lighting to improve campanula stock plant morphology and cutting quality. Generally, the monochromatic lights did not affect the seed germination response compared to darkness. Among the monochromatic lights, R, G, and UVB were the most promotive. Gerbera seedlings grown under RB-LED had as good a quality as those under fluorescent light and including a third light spectrum did not affect their growth and morphology. Dynamic R and B lighting can promote plant elongation without negatively affecting cutting quality, and with a mix of photoperiods, can be used as an effective lighting strategy for producing campanula stock plants for machine-harvest of cuttings.