Abstract
Major light factors affecting plant growth are light quality, light intensity, photoperiod, and the day/night cycle. These parameters can be controlled under greenhouse conditions using artificial light sources. Moreover, application of light pulses and shortterm changes of the spectral composition are effective ways to stimulate plants and to induce desired morphological developments. Controlling spectral qualities of the irradiation applied enables faster growth or higher yield at a given radiation energy, and the production of plants of optimized nutritional value. Recent developments of lighting technology have enabled not only researchers but also farmers to control spectral qualities by combinations of various light sources with different waveband emissions. This review summarizes previous papers and evaluates significant effects of the quality of artificial light on growth and development of higher plants, especially crops.
