"It has been found that white, full-spectrum-based LED lighting leads to healthier and more balanced growth compared to narrow spectrum-based LED lighting," the Samsung team shares.
As a technology provider in LEDs, Samsung carefully designs light spectra to optimize the effects of lighting on plant growth under various conditions.
Study 1: the effects of white lights with various wavelengths
To ensure the constant development of its product, Samsung has collaborated with Gyeongsang National University in Korea to conduct multiple experimental studies, demonstrating how Samsung's specifically engineered spectra help boost plant growth. The details and results of these experiments can be found in the journals below.
The first study by Dr. Son from the Department of Horticultural Science at Gyeongsang National University in Korea, supported by Samsung Electronics' LEDs, examined the effect of white LED lighting with specific shorter blue and/or green wavelengths on butterhead and romaine lettuce.
This study aimed to examine the effect of W LED light sources on the growth and quality of butterhead and romaine lettuce. Three W LED light sources, normal W light (NWL), and two specific W lights (SWL1 – Samsung's LM301H EVO Mint White and SWL2 – Samsung's LM301H EVO) with shorter blue peak wavelength (437 nm), were used to grow lettuce in comparison to narrowing a red (R) and blue (B) LED combination (RB).
The results showed that the SWL1 and SWL2 treatments, with the same electrical power or photosynthetic photon flux density (PPFD), resulted in more growth of both lettuce cultivars compared to the RB treatment. Some phenolic and flavonol contents were increased in the RB treatment. Whereas the SWL2 treatment stimulated the accumulation of other phenolic and flavonol compounds. Meanwhile, neither NWL nor SWL1 treatments increased the individual phenolic and flavonol contents in either cultivar (except for some flavonols in romaine lettuce in the SWL1 group).
In addition, light and energy use efficiencies were also highest in the SWL1 and SWL2 treatments. These results illustrate the positive effects of specific W LED light on lettuce growth and quality and suggest that the specific W LED light sources, especially SWL2 – the LM301H EVO, could be preferably used in vertical farming. The study concluded that specific white LED lights with shorter blue peak wavelengths could benefit the growth and quality of lettuce in vertical farming systems.
Study 2: Cherry tomato response to full-spectrum LEDs
This second study was conducted by Gyeongsang National University in Korea, supported by Samsung Electronics' LED Business. They aimed to evaluate the impact of specific white-based full-spectrum supplemental LED lighting on cherry tomato plants.
Supplemental artificial light in greenhouses is fundamental to achieving sustainable crop production with high yield and quality. This study aimed to investigate the efficacy of supplemental light (SL) sources on cherry tomatoes' vegetative and reproductive growth.
The research team examined various growth parameters, including plant height, stem diameter, leaf area, and fruit yield, as well as the content of bioactive compounds in cherry tomatoes. Four types of light sources were applied, including high-pressure sodium lamps (HPS), a narrow-spectrum LED light (NSL), and two specific full-spectrum LED lights (SFL1 – Samsung's LM301H EVO with LH351H Deep Red 660nm V2 and SFL2 – Samsung's LM301H EVO Mint White with LH351H Deep Red 660nm V2) with a shorter blue peak wavelength (436 nm) and/or green peak wavelength (526 nm).
The control was the natural light condition. The study showed that specific white-based full-spectrum supplemental LED lighting significantly affected cherry tomato growth and fruit yield. The plants grown under the specific LED lighting exhibited increased plant height, stem diameter, leaf area, and fruit yield compared to the control group.
The HPS and NSL treatments also enhanced tomato growth but were less efficient than the SFL treatments. The SFL1 and SFL2 treatments showed higher fruit yields by 73.1% and 70.7%, respectively, than the control. Additionally, the cherry tomatoes grown under the specific LED lighting had higher levels of bioactive compounds, which benefit human health. The SL sources did not affect the effective photochemical quantum yield of photosystem II (Y (II)). However, they did trigger the increased electron transport rate (ETR) and non-photochemical quenching (NPQ). The SFL treatments enhanced tomato growth, fruit yield, and efficient use of light and energy, suggesting that the specific full spectrum based on the short-wavelength blue and/or green peak can be successfully applied to cultivate cherry tomatoes and other crops in greenhouses.
These findings suggest that specific white-based full-spectrum supplemental LED lighting can enhance the growth, fruit yield, and bioactive compound content of cherry tomato plants.