Improving “color rendering” of LED lighting for the growth of lettuce

Abstract

Light plays a vital role on the growth and development of plant. On the base of white light with high color rendering to the benefit of human survival and life, we proposed to improve “color rendering” of LED lighting for accelerating the growth of lettuce. Seven spectral LED lights were adopted to irradiate the lettuces under 150 μmol·m−2·s−1 for a 16 hd−1 photoperiod. The leaf area and number profiles, plant biomass, and photosynthetic rate under the as-prepared LED light treatments were investigated. We let the absorption spectrum of fresh leaf be the emission spectrum of ideal light and then evaluate the “color rendering” of as-prepared LED lights by the Pearson product-moment correlation coefficient and CIE chromaticity coordinates. Under the irradiation of red-yellow-blue light with high correlation coefficient of 0.587, the dry weights and leaf growth rate are 2–3 times as high as the sharp red-blue light. The optimized LED light for lettuce growth can be presumed to be limited to the angle (about 75°) between the vectors passed through the ideal light in the CIE chromaticity coordinates. These findings open up a new idea to assess and find the optimized LED light for plant growth.

Optimization of LED Lighting and Quality Evaluation of Romaine Lettuce Grown in An Innovative Indoor Cultivation System

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Synthesis and photoluminescence properties of a novel red phosphor SrLaGaO4:Mn4+

“…One of the critical steps of indoor plant cultivation is to find reliable light sources which can provide tunable light spectrum to fit different plant photoreceptors. Light emitting diodes (LEDs) with overwhelming advantages of energy saving, compactness, long lifetime, and environmental friendliness as well as controllable light colors have defeated conventional incandescent, metal‐halide, and fluorescent lamps as the major artificial light sources for plant cultivation . Compared with blue and red LEDs, the fabrication of far‐red‐emitting LEDs is relatively more difficult.…”

Increasing the Energy Savings and Yield of <em>Lactuca sativa</em>, L. in Glass Greenhouses through Illumination Spectral Filtering

“…The published literature sources have thus far not investigated using white LED lighting systems as a control group, and comparing the biomass increases under various different light conditions to this control. That which has been considered so far is to determine the optimized LED light for plant growth [19]. Han et al have indicated that Red, Yellow and Blue combinations with good "color rendering" is for the benefit of the growth of the plant [19].…”