How Do White LEDs’ Spectra Affect the Fresh Weight of Lettuce Grown under Artificial Lighting in a Plant Factory?—A Statistical Approach

Lu, Na; Saengtharatip, Suthisak; Takagaki, Michiko; Maruyama, Atsushi; Kikuchi, Masao

doi:10.4236/as.2019.107073

Cited by 10 publications

(9 citation statements)

References 27 publications

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“…The fresh lettuce weight was equal to 64.9 g plant -1 . The results were consistent with [23], where the lettuce was cultivated under warm white and natural white LEDs under PPFD of 200±10 µmol m -2 s -1 , CO 2 is 1200 ppm. The results of lettuce fresh weight were about 63.5-97.9 g plant -1 .…”

Section: Evaluation Of the 'Green Oak Lettuce' Production Yieldsupporting

confidence: 89%

Laboratory Scale Plant Factory Artificial Light: Primary Evaluation of the Light Environment, Resources Consumption and Yields

Watjanatepin¹,

Srichanin²

2021

Journal of Southwest Jiaotong University

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Plant factory artificial light (PEAL) is an attractive technology for producing high-value plants and medical-grade herbs. The PFAL research and development in Thailand are in their early stages. This article aims to design and construct the lab-scale PFAL, which includes several key features such as the lighting quality, the controls of the environment, and the embedded technology monitoring system. The lab-scale PEAL must evaluate the preliminary results of the artificial light parameters, resources consumption, the plant production yield, and the correlation between LED artificial light and the plant yields. The results demonstrated that our lab-scale PFAL consists of 27 m3 cultivation volumes. White-LED T8 (4091K) artificial light emitted, on average, the PPFD of 187±23 µmol m-2 s-1 with an R:B ratio of 1.8. The lettuce production yields show a strong positive correlation with the PPFD. The lettuce production yield is 76.23 g plant-1 under the temperature of 24.05℃, RH of 79.3%, and 923 ppm of CO2 concentration with a light period of 16/8 h. The PC-based monitoring and data acquisition control worked well during the crop experiments. The environmental parameters indicated that the results did not differ from the other PFALs. Electrical energy consumption data were also reasonable at 45%, 37%, and 17% of LED artificial light, air condition units, and other types of equipment, respectively. The artificial light sources have to improve the light uniformity and increase intensity. The lab-scale PFAL is very helpful in developing students’ skills in education and disseminating the knowledge and technical design of our PFAL to academic services. For future studies, efforts will be put in developing this PFAL to achieve higher productivity by balancing the resources consumption with the cloud-based control and monitor system.

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Section: Evaluation Of the 'Green Oak Lettuce' Production Yieldsupporting

confidence: 89%

Laboratory Scale Plant Factory Artificial Light: Primary Evaluation of the Light Environment, Resources Consumption and Yields

Watjanatepin¹,

Srichanin²

2021

Journal of Southwest Jiaotong University

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“…A typical PCW-LED comprises a blue-LED chip and phosphors of one or more types incorporated in the encapsulation resin, of which the phosphors convert partial blue-LED light into green or red light ( Cho et al, 2017). Some reports have described that PCW-LED light can enhance plant growth compared to BR-light ( Han et al, 2017;Lu et al, 2019;Nozue et al, 2018), even to BGR-light ( Saengtharatip et al, 2018). In addition, PCW-LEDs (blue-LED chip plus phosphors of one or more types) have been popularized rapidly for general lighting applications ( Han et al, 2017), of which the cost can be less than 20% of that of common red LEDs ( Kusuma et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

“…Several studies have compared the respective performances of PCW-LEDs of several types in growing plants. Their results have demonstrated that the relative SPD of PCW-LED light can strongly affect dry weight ( Han et al, 2017;Lu et al, 2019;Nozue et al, 2018;Saengtharatip et al, 2018;Zou et al, 2020). The results also indicate that the relative SPD of PCW-LEDs should be selected carefully to maximize dry mass production.…”

Section: Introductionmentioning

confidence: 99%

Rapid and semi-automated leaf net photosynthetic rate determination for numerous phosphor-converted white-LED lights of different spectral distributions

CHEN

Matsuda

Fujiwara

2022

J. Agric. Meteorol.

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Phosphor-converted white LEDs (PCW-LEDs) of numerous types with different relative spectral photon-flux-density distributions (SPDs) are commercially available today. Some are regarded as promising light sources for use in plant factories with artificial lighting. The leaf net photosynthetic rate (P n ) measured under PCW-LED light is an important criterion for evaluating PCW-LEDs in terms of photosynthesis performance. To ascertain P n rapidly under dozens of PCW-LED lights having different SPDs, we have developed a rapid and semi-automated P n -quantification method. The method uses a modified LED-artificial sunlight source system (LASS system) and a P n -measurement system. The modified LASS system can produce light with an SPD, which can accurately approximate that of any PCW-LED light at a photosynthetic photon flux density (PPFD) of 150 μmol m -2 s -1 . First, PCW-LED lights of 30 types at a PPFD of 150 μmol m -2 s -1 were produced using the modified LASS system within 2.5 h. We then measured the P n of cos lettuce, red-leaf lettuce, and green-leaf lettuce (Lactuca sativa L.) plants. In a 16-h P n measurement repetition, the modified LASS system supplied all the produced lights automatically and successively to an identical leaf of a lettuce plant. A P n -measurement system simultaneously measured P n under the produced light. Results show that the mean P n values of the cos lettuce, red-leaf lettuce, and green-leaf lettuce under the 30 produced lights at 20 days after sowing were, respectively, 7.11 -8.02, 5.76 -7.11, and 4.83 -6.17 μmol m -2 s -1 . A rapid and semi-automated method was developed for successive measurement of P n under dozens of combined lights, of which each SPD approximated that of the selected PCW-LED lights, within days, which indicates that the method can determine the P n quickly under numerous PCW-LED lights. Results show that the system contributes to rapid selection of PCW-LED lights performing high P n .

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“…A typical PCW-LED comprises a blue-LED chip and one or more types of phosphor incorporated in the encapsulation resin, of which the phosphors convert partial blue-LED light into green and/or red light [17]. Some reports have described that PCW-LED light can enhance plant growth compared to BR-light [16,18,19], even to BGR-light [11]. In addition, PCW-LEDs (blue-LED chip plus one or more types of phosphor) have been rapidly popularized for general lighting applications [16], of which the cost can be less than 20% of that of common red LEDs [20].…”

Section: Introductionmentioning

confidence: 99%

“…A few studies have compared the performance of PCW-LEDs of several types in growing plants; they have shown that the relative SPD of PCW-LED light can strongly affect dry mass production [11,18,19,21].…”

Section: Introductionmentioning

confidence: 99%

Rapid and automated leaf net photosynthetic rate determination for numerous phosphor-converted white-LED lights of different spectral distributions

Chen¹,

Matsuda²,

Fujiwara³

2020

Preprint

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BackgroundPhosphor-converted white LEDs (PCW-LEDs) of numerous types with different relative spectral photon-flux-density distributions (SPDs) are commercially available today. Some are regarded as promising light sources for plant factories with artificial lighting. Therefore, some methods must be developed for rapidly selecting appropriate ones from numerous types of PCW-LEDs with relevant evaluation criteria. For rapid determination of leaf net photosynthetic rates (Pn) under dozens of PCW-LED lights with different SPDs, we have developed a rapid and mostly automated Pn-quantification method.ResultsThe method uses a modified LED-artificial sunlight source system (LASS system) and a Pn-measurement system. The modified LASS system includes LEDs of 30 types with different relative SPDs: monochromatic LEDs of 27 types (426–826 nm peak wavelengths) and PCW-LEDs of three types. The system combines the LED lights to produce light with an SPD, which can accurately approximate that of any PCW-LED light at a photosynthetic photon flux density (PPFD) of 150 μmol m−2 s−1. The Pn-quantification method includes two steps: Step 1 – producing the selected PCW-LED lights; Step 2 – using the modified LASS system to supply all the produced lights automatically and successively to an identical leaf and simultaneously measuring Pn using a Pn-measurement system. We produced PCW-LED lights of 30 types at a PPFD of 150 μmol m−2 s−1 within 2.5 h. Then we individually measured the Pn of cos lettuce, red-leaf lettuce, and green-leaf lettuce (Lactuca sativa L.) plants under all produced lights in 16 h per cultivar per repetition. Results show that the mean Pn values of the cos lettuce, red-leaf lettuce, and green-leaf lettuce under the 30 produced lights were, respectively, 7.11–8.02, 5.76–7.11, and 4.83–6.17 μmol m−2 s−1 at 20 days after sowing.ConclusionsA rapid and greatly automated method was developed for successive measurement of Pn under dozens of combined lights, of which each SPD approximated that of the selected PCW-LED lights, within days, which indicates that the method can determine the Pn quickly under numerous PCW-LED lights. Consequently, it contributes to the rapid selection of PCW-LED lights performing high Pn.

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How Do White LEDs’ Spectra Affect the Fresh Weight of Lettuce Grown under Artificial Lighting in a Plant Factory?—A Statistical Approach

Cited by 10 publications

References 27 publications

Laboratory Scale Plant Factory Artificial Light: Primary Evaluation of the Light Environment, Resources Consumption and Yields

Laboratory Scale Plant Factory Artificial Light: Primary Evaluation of the Light Environment, Resources Consumption and Yields

Rapid and semi-automated leaf net photosynthetic rate determination for numerous phosphor-converted white-LED lights of different spectral distributions

Rapid and automated leaf net photosynthetic rate determination for numerous phosphor-converted white-LED lights of different spectral distributions

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