Light is a vital environmental factor that affects plant growth and development by acting on plants not only as the sole energy source of photosynthesis, but also as the kind of external signal. Application of artificial light (AL) in ornamental plants is becoming increasingly widespread. Artificial light is used for improving yield, extending the production season, improving product quality and as photoperiodic light for the control of flowering in day length-sensitive species. Successful artificial lighting for plant growth must balance quality, intensity and photoperiod. A number of different artificial light sources are commercially available such as incandescent lamps, fluorescent lamps, high pressure sodium lamps (HPS) and more recently light emitting diodes (LED) that differ in the light quality they emit. Light-emitting diodes pave the way for a better understanding of the interaction between light and pests, diseases, natural enemies and plants, as they make possible the use of very narrow wavelengths. LED as an option for reducing the use of growth retardants and obtaining better product quality in ornamental plants.
Artificial light, LED, photoperiod, ornamental plants
