Effects of Blue and Green Light on Plant Growth and Development at Low and High Photosynthetic Photon Flux

Research in photobiology dates back over 200 years with studies using primitive light sources. This early research identified photoreceptors and action spectra for specific regions of the light spectrum that are paramount for photosynthesis as well as growth and development that are still topics of interest today. Photobiological research has become an area of increasing interest since the introduction of light-emitting diodes which allow for evaluating endless combinations of light spectra. Red light-light emitting diodes were the first to be introduced that had an electrical efficiency comparable to existing light sources. The research found that red light alone was not sufficient to promote normal plant growth and development in most species and that some blue light supplementation was needed. The amount of blue light required has been extensively studied with varying results. The introduction of light emitting diodes has also allowed for studies of the effects of green light on plant growth and development. The influence of green light, similar to blue light, has resulted in varying conclusions, mainly regarding the importance of green light for photosynthesis. This research will provide important information on optimal light quality for commercial greenhouse and controlled environmental food production