Light-Emitting Diodes (LEDs) for Miniature Hydroponic Lettuce

Kobayashi, Kent D.; Amore, T.D.; Lazaro, Michelle

doi:10.4236/opj.2013.31012

Cited by 66 publications

(40 citation statements)

References 11 publications

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“…The total Chl content decreased under monochromatic light, indicating that monochromatic light causes damage to the photosynthetic pigments. However, compared to R light, B light treatment resulted in significantly higher leaf Chl content, which is inconsistent with the results of studies on lettuce and Anoectochilus roxburghii [46,47]. In this study, the P n of Welsh onion seedlings was significantly lower when grown under monochromatic light than under the W light treatment, especially under Y and G lights (Fig.…”

Section: Discussioncontrasting

confidence: 99%

Photosynthetic characteristics and chloroplast ultrastructure of welsh onion (Allium fistulosum L.) grown under different LED wavelengths

Gao

Liu

et al. 2020

BMC Plant Biol

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Background: The optimized illumination of plants using light-emitting diodes (LEDs) is beneficial to their photosynthetic performance, and in recent years, LEDs have been widely used in horticultural facilities. However, there are significant differences in the responses of different crops to different wavelengths of light. Thus, the influence of artificial light on photosynthesis requires further investigation to provide theoretical guidelines for the light environments used in industrial crop production. In this study, we tested the effects of different LEDs (white, W; blue, B; green, G; yellow, Y; and red, R) with the same photon flux density (300 μmol/m 2 •s) on the growth, development, photosynthesis, chlorophyll fluorescence characteristics, leaf structure, and chloroplast ultrastructure of Welsh onion (Allium fistulosum L.) plants. Results: Plants in the W and B treatments had significantly higher height, leaf area, and fresh weight than those in the other treatments. The photosynthetic pigment content and net photosynthetic rate (P n) in the W treatment were significantly higher than those in the monochromatic light treatments, the transpiration rate (E) and stomatal conductance (G s) were the highest in the B treatment, and the intercellular CO 2 concentration (C i) was the highest in the Y treatment. The non-photochemical quenching coefficient (NPQ) was the highest in the Y treatment, but the other chlorophyll fluorescence characteristics differed among treatments in the following order: W > B > R > G > Y. This includes the maximum photochemical efficiency of photosystem II (PSII) under dark adaptation (Fv/Fm), maximum photochemical efficiency of PSII under light adaptation (Fv′/Fm′), photochemical quenching coefficient (qP), actual photochemical efficiency (ΦPSII), and apparent electron transport rate (ETR). Finally, the leaf structure and chloroplast ultrastructure showed the most complete development in the B treatment. Conclusions: White and blue light significantly improved the photosynthetic efficiency of Welsh onions, whereas yellow light reduced the photosynthetic efficiency.

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Section: Discussioncontrasting

confidence: 99%

Photosynthetic characteristics and chloroplast ultrastructure of welsh onion (Allium fistulosum L.) grown under different LED wavelengths

Gao

Liu

et al. 2020

BMC Plant Biol

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“…LEDs generate relatively low heat compared with high-pressure sodium lamp, fluorescent lamp, and hybrid electrode fluorescent lamp (HEFL), and it reduces the damage to the plants and consumes less electricity (Kim 2010). For its advantage, much research on the productivity and physiological response of flowers and crop plants such as chrysanthemum, Phalaenopsis, Petunia, rocket salad, lamb's lettuce, lettuce, cucumber, wheat, spinach, radish, tomato, and rice cultivated in glasses, in greenhouses, or in plant factories has been reported (Goins et al 1997;Yorio et al 2001;Matsuda et al 2004;Trouwborst et al 2010;Lu et al 2012;Im et al 2013;Kim et al 2013;Kobayashi et al 2013;Wojciechowska et al 2013;Phansurin et al 2017;Lee et al 2017;Kim et al 2018).…”

Section: Introductionmentioning

confidence: 99%

The effects of LEDs and duty ratio on the growth and physiological responses of Silene capitata Kom., endangered plant, in a plant factory

et al. 2018

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Background: In this study, we observed their growth and physiological responses using a variety of duty ratio under the mixed light using red, blue, and white lights. The red+blue mixed light was treated with 95%, 90%, 85%, 80%, and 75% duty ratios and red+blue+white mixed light with 85% and 70% duty ratios. We examined the width and length of leaves, total number of leaves, and number of shoots to examine their growth responses. The physiological responses were studied by measuring their photosynthetic rate, transpiration rate, stomatal conductance, water use efficiency, chlorophyll content, and fluorescence (F o , F m , and F v /F m). Results: We found that lower duty ratio caused the length and width of the leaves to grow longer under red+blue mixed light but that it did not cause any difference in the red+blue+white mixed light condition. In addition, there was no difference in the number of leaves and shoots among all treatments. In the red+blue mixed light condition, the photosynthetic rate was no difference, but both transpiration rate and stomatal conductance were the highest at 95% duty ratio than in other ratios. Water use efficiency pattern was similar to that of photosynthetic rate; water use efficiency was no difference. Chlorophyll content was the highest at 95% duty ratios, and it was the least at 90%, 85%, and 75% duty ratio. F o and F m values were relatively high at 85% and 80% duty ratio and low at 90% duty ratio while F v /F m showed no difference. Conclusions: Under the red+blue+white mixed light, all physiological items showed no difference between 70 and 85% treatments. But, photosynthetic rate, water use efficiency, chlorophyll content, and F v /F m were relatively greater in the red+blue+white mixed light than in the red+blue mixed light. Therefore, red+blue+white mixed light treated with 70% duty ratio could lessen the environmental stress and save more power when cultivating Silene capitata in a plant factory.

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“…Varying effects of light quality on the biomass, physiology, and biochemical contents of lettuce have been reported. Blue light, e.g., promotes the growth of lettuce plants (Johkan et al, 2010) and also increases Chl content and total phenolic and flavonoid concentrations (Son and Oh, 2013), whereas lettuce illuminated with red light shows comparably higher SDW (Kobayashi et al, 2013) and leaf area (Wu et al, 2007). A combination of red and blue light has also been proven to enhance the growth and biomass of lettuce grown in a controlled environment (Yorio et al, 2001).…”

mentioning

confidence: 99%

Influence of Light Quality and Intensity on Biomass and Biochemical Contents of Hydroponically Grown Lettuce

Lin¹,

Huang²,

Xu³

2018

horts

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The effects of different light intensities and qualities on the biomass, physiological parameters, and biochemical contents of hydroponically grown lettuce (Lactuca sativa L.) were evaluated, with the aim of obtaining better quality and higher yield, as well as saving energy in lettuce cultivation. Three different light qualities, provided by red (R), green (G), and blue (B) light-emitting diodes (LEDs), were used to produce six different combinations of illumination: A1: R:G:B = 7:0:3 [photosynthetic photon flux density (PPFD) = 150 μmol·m−2·s−1]; A2: R:G:B = 6:2:2 (150 μmol·m−2·s−1); A3: R:G:B = 7:0:3 (120 μmol·m−2·s−1); B1: R:G:B = 3:0:7 (150 μmol·m−2·s−1); B2: R:G:B = 2:2:6 (150 μmol·m−2·s−1); and B3: R:G:B = 3:0:7 (120 μmol·m−2·s−1), and the fluorescent lamp (FL) at 150 μmol·m−2·s−1 was used as the control (CK). In most cases, treatment A2 resulted in higher biomass attributes, whereas higher physiological parameters were observed in treatment B2. However, a greater shoot dry weight (SDW) was observed in treatment A1. No significant difference was detected in chlorophyll [Chl (a + b)] and carotenoid (CAR) contents among the different treatments. Soluble sugar content was found the highest in treatment A1, although it was not significant compared with that observed in treatment A2. Soluble protein content was higher in treatments with a higher component of blue light. Vitamin C content was found the highest in treatment B3 and the lowest in treatment A1, whereas malondialdehyde (MDA) content was the highest in CK and the lowest in treatments B1 and B2. These results indicated that appropriate ratio of red to blue light can effectively promote the accumulation of biochemical compounds in lettuce and that replacement of a certain portion of red light, blue light, or both with green light was more effective in promoting plant growth and quality.

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Light-Emitting Diodes (LEDs) for Miniature Hydroponic Lettuce

Cited by 66 publications

References 11 publications

Photosynthetic characteristics and chloroplast ultrastructure of welsh onion (Allium fistulosum L.) grown under different LED wavelengths

Photosynthetic characteristics and chloroplast ultrastructure of welsh onion (Allium fistulosum L.) grown under different LED wavelengths

The effects of LEDs and duty ratio on the growth and physiological responses of Silene capitata Kom., endangered plant, in a plant factory

Influence of Light Quality and Intensity on Biomass and Biochemical Contents of Hydroponically Grown Lettuce

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