Impact of Light-Emitting Diodes (LEDs) and its Potential on Plant Growth and Development in Controlled-Environment Plant Production System

Background: Canopy light environment plays a crucial role in plant growth and development. Gasdischarge lamps (GDLs) are typically used in controlled-environment crop production system for illuminating crops. GDLs have broad emission spectra and heat-up significantly during operation. The advent of light-emitting diodes (LEDs) has provided the means for developing a lighting system for growing crops that is more power-economical and customizable than the conventional lighting systems. LED treatments with specific irradiation wavelengths and intensities may trigger photoreceptors to induce desired morphological and physiological changes in the crops. Objective: The present review describes the advantages of LEDs over the conventionally used GDLs from the perspective of its implementation in controlled-environment crop production along with its working principle and potential. Methods: Various food crops and ornamental plants were grown in controlled-environment chambers under LED treatments of various wavelengths. A variety of parameters including morphological, physiological and biochemical were studied to assess the impact of LEDs on plant growth and development. Results: Salient features of controlled-environment plant growth experiments conducted with LEDs as the light source have been summarized, outlining the variety of responses exhibited by different plant species to specific LED treatments. Conclusion: LED lighting systems are capable of providing customized light treatments to improve yield and enhance various qualitative traits in different crop species. The studies are thus indicative of the potential of LEDs as the next generation light source for controlled-environment crop production.