Effects of Light Quality on Growth of Crop Plants under Artificial Lighting

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.

Developmental Responses of Wheat cv. Norin 61 to Fluence Rate of Green Light

“…Under the canopy, the proportions of blue light and red light are decreased; those of green and farred light are slightly increased (Smith, 1982;Kasajima et al, 2006). When plants sense the low red:far-red ratio (R:FR) by dense plant canopies, they elongate more rapidly and accelerate development to produce seeds early for survival (Goto, 2003). In the present study, increased green light under the dense canopies might function to regulate the development and culm elongation.…”

“…In addition, LEDs have a pronounced peak wavelength in monochromatic green light (Goto, 2003). The spectral range of green light is 500−550 nm (Kasajima et al, 2007), and that of photosynthetic photon fl ux density (PPFD) is 400− 700 nm.…”

Plant Responses to Extended Photosynthetically Active Radiation (EPAR)

“…1 The importance of light quality in plant growth has been previously reviewed. 41,42 PAR is generally monopolized for research focused on photosynthesis;…”

Photosynthetic Capacities and Productivity of Indoor Hydroponically Grown <i>Brassica alboglabra</i> Bailey under Different Light Sources

“…Much research has been carried out on the action spectrum of photosynthesis [24]. However, the effect of different RB-LED ratios on photosynthesis of specific species remains unclear [25] [26]. For instance, studies with red leaf lettuce, showed that the difference of 5% to 10% blue-LED changed total dry weight of the plants significantly.…”