Effects of Light Emitting Diode Lights on Plant Growth, Development and Traits A Meta-analysis

Abstract

Abstract The various monochromatic Light Emitting Diode (LED) lights are widely used in growth facility for cultivating various plants, particularly horticultural crops because of their higher luminous efficiency, lower radiation and power consumption than the traditional white fluorescent lamp light. However, considerable inconsistent effects have been reported in literature. We conducted a meta-analysis to assess the effects of different colors of LED light on plant growth, development and various traits. Compared to the light from white fluorescent lamps, the red LED light significantly changed 4 out 26 plant characteristics by at least 37%, and blue LED light significantly increased 5 of 26 assessed characteristics by 37% or more. The combination of red/blue LED lights only significantly increased dry weight by 161% among 25 plant characteristics analyzed. Compared to the white LED light, red LED light significantly decreased 2 of 9 plant characteristics by at least 36%, and blue LED light significantly decreased only 1 of 9 plant characteristics, total chlorophyll content, by 42%. In the moderators analyzed, plant taxonomic families significantly influenced the effects of LED lights on shoot dry weight, and plant life cycles and plant taxonomic families significantly affected the effect on stomatal conductance. Through systematic meta-analysis, we found that the effect of LED on plant growth and quality traits was species-specific, and the effect was affected by the cultivation conditions. Therefore, we suggest that researchers be more targeted to experiment, and collect traits associated with practical production, especially related to the quality of product data, such as carotenoids, anthocyanin and other antioxidant compounds. This article is to provide more data with practical application, guide the application of LED in horticultural plant factory.