Pulsed LED-Lighting as an Alternative Energy Savings Technique for Vertical Farms and Plant Factories

Different strategies are reported in the literature for energy saving in Closed Plant Production Systems (CPPS). However, not reliable evidences about energy consumption with the use of pulsed LED light technique in lighting system available in Plant Factory and Vertical Farm. In this work, three key points to determine the effects of pulsed LED light versus continuous LED light are presented: (1) A mathematical model and its practical application for stabilizing the energy equivalence using LED light in continuous and pulsed mode in different light treatments. (2) The quantum efficiency of the photosystem II was used to determine positive and/or negative effects of the light operating mode (continuous or pulsed) on chili pepper plants (Capsicum annuum var. Serrano). (3) Evaluation of energy consumption with both operation modes using ten recipes from the literature to grow plants applied in Closed Plant Production Systems, different Photosynthetic Photon Flux Density at 50, 110, and 180 µmol m−2 s−1, Frequencies at 100, 500, and 1000 Hz, and Duty Cycles of 40, 50, 60, 70, 80, and 90%. The results show no significant statistical differences between the operation modes (continuous and pulsed LED light). For each light recipe analyzed, a pulsed frequency and a duty cycle were obtained, achieving significant energy savings in every light intensity. The results can be useful guide for real-life applications in CPPS.

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Modeling Energy LED Light Consumption Based on an Artificial Intelligent Method Applied to Closed Plant Production System

Applied Sciences ◽

10.3390/app11062735 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2735

Author(s):

Ernesto Olvera-Gonzalez ◽

Martín Montes Rivera ◽

Nivia Escalante-Garcia ◽

Eduardo Flores-Gallegos

Keyword(s):

Energy Consumption ◽

Energy Savings ◽

Nonlinear Models ◽

Light Emitting Diode ◽

Red Light ◽

Green Light ◽

Plant Production ◽

Production Plant ◽

Light Component ◽

Gp Model

Artificial lighting is a key factor in Closed Production Plant Systems (CPPS). A significant light-emitting diode (LED) technology attribute is the emission of different wavelengths, called light recipes. Light recipes are typically configured in continuous mode, but can also be configured in pulsed mode to save energy. We propose two nonlinear models, i.e., genetic programing (GP) and feedforward artificial neural networks (FNNs) to predict energy consumption in CPPS. The generated models use the following input variables: intensity, red light component, blue light component, green light component, and white light component; and the following operation modes: continuous and pulsed light including pulsed frequency, and duty cycle as well energy consumption as output. A Spearman's correlation was applied to generate a model with only representative inputs. Two datasets were applied. The first (Test 1), with 5700 samples with similar input ranges, was used to train and evaluate, while the second (Test 2), included 160 total datapoints in different input ranges. The metrics that allowed a quantitative evaluation of the model's performance were MAPE, MSE, MAE, and SEE. Our implemented models achieved an accuracy of 96.1% for the GP model and 98.99% for the FNNs model. The models used in this proposal can be applied or programmed as part of the monitoring system for CPPS which prioritize energy efficiency. The nonlinear models provide a further analysis for energy savings due to the light recipe and operation light mode, i.e., pulsed and continuous on artificial LED lighting systems.

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Different LED Light Wavelengths and Photosynthetic Photon Flux Density Effect on Colletotrichum acutatum Growth

Plants ◽

10.3390/plants11010143 ◽

2022 ◽

Vol 11 (1) ◽

pp. 143

Author(s):

Neringa Rasiukevičiūtė ◽

Aušra Brazaitytė ◽

Viktorija Vaštakaitė-Kairienė ◽

Alma Valiuškaitė

Keyword(s):

Flux Density ◽

Photosynthetic Photon Flux Density ◽

Growth Characteristics ◽

Colletotrichum Acutatum ◽

Photon Flux ◽

Photon Flux Density ◽

Photosynthetic Photon Flux ◽

Light Emitting ◽

Led Light ◽

Fungus Growth

The study aimed to evaluate the effect of different photon flux density (PFD) and light-emitting diodes (LED) wavelengths on strawberry Colletotrichum acutatum growth characteristics. The C. acutatum growth characteristics under the blue 450 nm (B), green 530 nm (G), red 660 nm (R), far-red 735 nm (FR), and white 5700 K (W) LEDs at PFD 50, 100 and 200 μmol m−2 s−1 were evaluated. The effect on C. acutatum mycelial growth evaluated by daily measuring until five days after inoculation (DAI). The presence of conidia and size (width and length) evaluated after 5 DAI. The results showed that the highest inhibition of fungus growth was achieved after 1 DAI under B and G at 50 μmol m−2 s−1 PFD. Additionally, after 1–4 DAI under B at 200 μmol m−2 s−1 PFD. The lowest conidia width was under FR at 50 μmol m−2 s−1 PFD and length under FR at 100 μmol m−2 s−1 PFD. Various LED light wavelengths influenced differences in C. acutatum colonies color. In conclusion, different photosynthetic photon flux densities and wavelengths influence C. acutatum growth characteristics. The changes in C. acutatum morphological and phenotypical characteristics could be related to its ability to spread and infect plant tissues. This study’s findings could potentially help to manage C. acutatum by LEDs in controlled environment conditions.

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The effects of linght emitting diode lighting on growth and development of A. annanesis and A. roxburghii in vitro cultured shoots

TAP CHI SINH HOC ◽

10.15625/0866-7160/v40n1.10636 ◽

2017 ◽

Vol 40 (1) ◽

pp. 32-38

Author(s):

Phan Xuan Binh Minh ◽

Bui Thi Thanh Phuong ◽

Pham Huong Son ◽

Tran Minh Hoi ◽

Nguyen Thi Phuong Lan ◽

...

Keyword(s):

Growth And Development ◽

Photosynthetic Photon Flux Density ◽

Culture Conditions ◽

Plant Production ◽

Photon Flux ◽

Photon Flux Density ◽

Endangered Plants ◽

Operating Life ◽

Suitable Habitats

A. annamensis and A. roxburghii belong to Orchidaceae family that has medicinal and ornamental plant value. They are in extinct endangered plants in wild due to the over- collected and loss of the suitable habitats. Using the LED lighting source for culture these species in in vitro condition to optimize the culture conditions, reduction of the production cost, especially electric bill for air-corditionning, lighting. In recent years, the trial applied LED which has the feature of energy saving, small size and a longer operating life, for plant production has started. In this study, LED illumination sources are in four different wavelengths of λ= 430- 470 nm; λ= 470-510 nm; λ= 510-560 nm; λ= 560-600 nm and white fluorescent lamp as control with light intensity photosynthetic photon flux density (PPFD) of 40 µmol/m2/s photon used to study their effects on the growth and development of A. annamensis and A. roxburghii species. After 8 weeks of implementing, the results showed that the LEDs of λ= 470-510 nm were suitable for the growth and development for A. roxburghii shoots while for A. annamensis, λ = 430- 470 nm were most suitable for budding and λ= 470-510 nm for shoot growth. Citation: Phan Xuan Binh Minh, Bui Thi Thanh Phuong, Pham Huong Son, Tran Minh Hoi, Nguyen Thi Phuong Lan, Vu Thi Thao, 2018. The effects of linght emitting diode lighting on growth and development of A. annanesis and A. roxburghii in vitro cultured shoots. Tap chi Sinh hoc, 40(1): x-xx. DOI: 10.15625/0866-7160/v40n1.10636. *Corresponding author: [email protected] Received 23 August 2017, accepted 2 December 2017

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Growth Characteristics of Adenophora triphylla var. japonica Hara Seedlings as Affected by Growing Medium

Plants ◽

10.3390/plants8110466 ◽

2019 ◽

Vol 8 (11) ◽

pp. 466

Author(s):

Hye Ri Lee ◽

Hyeon Min Kim ◽

Hyeon Woo Jeong ◽

Gam Gon Kim ◽

Chae In Na ◽

...

Keyword(s):

Production System ◽

Germination Rate ◽

Leaf Length ◽

Growth Characteristics ◽

Plant Production ◽

Photon Flux ◽

Photon Flux Density ◽

Root Surface Area ◽

Root Tips ◽

Closed Type

Adenophora triphylla var. japonica Hara is a highly valued medicinal plant that is used to treat or prevent bronchitis, cough, cancer, and obesity. However, there has been no study on the production of Adenophora triphylla var. japonica Hara seedlings in a closed-type plant production system (CPPS). This study was conducted to examine the growth characteristics of Adenophora triphylla var. japonica Hara seedlings as affected by different growing media. The seeds were sown on a 128-cell plug tray filled with urethane sponges (US), LC grow foam (LC), rockwool (RW), or terra-plugs (TP). The seedlings were cultured for a duration of 54 days under temperature 25 ± 1°C, a photoperiod of 12/12 h (light/dark), and light intensity of 180 µmol·m−2·s−1 photosynthetic photon flux density provided by RB LEDs (red:blue = 8:2) in a closed-type plant production system (CPPS). The germination rate of Adenophora triphylla var. japonica Hara was significantly highest in the TP. Also, seedling shoot growth indicators of plant height, leaf length, leaf width, number of leaves, fresh weight (FW), and dry weight (DW) of the shoot, and leaf area were markedly the greatest in the TP and the lowest in the US. The SPAD (soil-plant analysis development) value was higher in the TP and US than in the LC or RW. In addition, the seedling root growth characteristics of total root length, root surface area, root volume, and number of root tips were significantly greatest in the TP. Moreover, the maximum root diameter, FW and DW of roots were the greatest in the TP. In conclusion, the results suggest that TP are viable for the growth development of Adenophora triphylla var. japonica Hara seedlings.

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Effects of White LED Lighting with Specific Shorter Blue and/or Green Wavelength on the Growth and Quality of Two Lettuce Cultivars in a Vertical Farming System

Agronomy ◽

10.3390/agronomy11112111 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2111

Author(s):

Thi Kim Loan Nguyen ◽

Kye Man Cho ◽

Hee Yul Lee ◽

Du Yong Cho ◽

Ga Oun Lee ◽

...

Keyword(s):

Energy Use ◽

Light Emitting Diode ◽

Photon Flux ◽

Photon Flux Density ◽

Light Sources ◽

Romaine Lettuce ◽

Led Light ◽

Positive Effects ◽

Vertical Farming

White (W) light-emitting diode (LED) light has been used as an efficient light source for commercial plant cultivation in vertical farming. 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 including normal W light (NWL) which has 450 nm as its pumping wavelength and two specific W lights (SWL1 and SWL2) with shorter blue peak wavelength (437 nm) were used to grow lettuce in comparison to a red (R) and blue (B) LED combination. As a result, 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 RB treatment. Some phenolic and flavonol contents were increased in the RB treatment, whereas 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, could be preferably used in vertical farming.

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LED Light Pre-Treatment Improves Pre-Basic Seed Potato (Solanum tuberosum L. cv. Golden King) Production in the Aeroponic System

Agronomy ◽

10.3390/agronomy11081627 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1627

Author(s):

Md. Hafizur Rahman ◽

Md. Jahirul Islam ◽

Md. Obyedul Kalam Azad ◽

Md. Soyel Rana ◽

Byeong Ryeol Ryu ◽

...

Keyword(s):

Seed Potato ◽

Seed Tuber ◽

Solanum Tuberosum L ◽

Spectral Composition ◽

Photon Flux ◽

Photon Flux Density ◽

Light Spectrum ◽

Led Light ◽

Pre Treatment ◽

Basic Seed

Production of plants under artificial light conditions is an innovative and smart concept to grow food year-round in any location. However, pre-basic seed potato production in the greenhouse from LED pre-treated seedlings under an aeroponic system is a new and creative idea. Therefore, the objective of the study was to optimize the effect of LED pre-treatment and determine the best LED spectral composition on growth performance and tuberization of potato plants. Potato variety ‘Golden King’ was treated under 9 LED light spectra for 30 days—L1 (natural light), L2, (R:B), L3 (R:B:G), L4 (R:B:FR), L5 (R:B:G:FR), L6 (R:B:G:FR:UV), L7 (R:B:FR:UV), L8 (R:B:W:FR), and L9 (R:B:W:FR:UV) under 300 µmol m−2 s−1 photosynthetic photon flux density (PPFD), 23/15 °C (day/night) temperature, and 70% relative humidity. The study revealed that growth characteristics and tuber number for plants were increased most by the light spectrum L4 (R:B:FR). Furthermore, photosynthetic pigments increased in L4, L7, and L8, while TSC and sucrose accumulated more in L1 treatment. In contrast, higher seed tuber fresh weight was recorded in L8, L9, L4, and L7. Overall, it can be concluded that potato seedlings pre-treated with the L4 (R:B:FR) LED spectral composition performed best for growth, establishment, and tuberization.

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Impact of light on leaf initiation: a matter of photosynthate availability in the apical bud?

Functional Plant Biology ◽

10.1071/fp13217 ◽

2014 ◽

Vol 41 (5) ◽

pp. 547 ◽

Cited By ~ 10

Author(s):

Andreas Savvides ◽

Nikolaos Ntagkas ◽

Wim van Ieperen ◽

Janneke A. Dieleman ◽

Leo F. M. Marcelis

Keyword(s):

Plant Growth ◽

Heat Budget ◽

Carbohydrate Content ◽

Plant Production ◽

Photon Flux ◽

Photon Flux Density ◽

Co2 Uptake ◽

Tomato Plants ◽

Leaf Initiation ◽

Apical Bud

Radiation substantially affects leaf initiation rate (LIR), a key variable for plant growth, by influencing the heat budget and therefore the temperature of the shoot apical meristem. The photosynthetically active component of solar radiation (photosynthetic photon flux density; PPFD) is critical for plant growth and when at shade to moderate levels may also influence LIR via limited photosynthate availability. Cucumber and tomato plants were subjected to different PPFDs (2.5–13.2 mol m–2 day–1) and then LIR, carbohydrate content and diel net CO2 uptake of the apical bud were quantified. LIR showed saturating response to increasing PPFD in both species. In this PPFD range, LIR was reduced by 20% in cucumber and by 40% in tomato plants. Carbohydrate content and dark respiration were substantially reduced at low PPFD. LIR may be considered as an adaptive trait of plants to low light levels, which is likely to be determined by the local photosynthate availability. In tomato and cucumber plants, LIR can be markedly reduced at low PPFD in plant production systems at high latitudes, suggesting that models solely based on thermal time may not precisely predict LIR at low PPFD.

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Effect of Colour of Light on Rooting Cuttings and Subsequent Growth of Chrysanthemum (Chrysanthemum × grandiflorum Ramat./Kitam.)

Agriculture ◽

10.3390/agriculture11070671 ◽

2021 ◽

Vol 11 (7) ◽

pp. 671

Author(s):

Anita Schroeter-Zakrzewska ◽

Faisal Anggi Pradita

Keyword(s):

Blue Light ◽

Growth Parameters ◽

Photosynthetic Photon Flux Density ◽

Flower Head ◽

Plant Production ◽

Photon Flux ◽

Photon Flux Density ◽

Subsequent Growth ◽

Number Of Leaves ◽

Leaf Greenness

A closed system for plant production with artificial light is an innovative method of plant cultivation. The objective of this study was to investigate the effect of light colour on rooting cuttings and subsequent growth of chrysanthemum (Chrysanthemum × grandiflorum Ramat./Kitam.) During the experiments, the following conditions were maintained: photoperiod 16 h or 10 h, temperature 22 °C, relative humidity of 65–70%. LED lamps emitted the following light colours: white, blue, white + blue (50:50), and red + blue (75:25). For all light spectra, the photosynthetic photon flux density (PPFD) was 50 μmol m−2 s−1. The effectiveness of exposure to different light colours was measured with parameters: cutting weight (g), cutting length (cm), length of roots, and index of leaf greenness (SPAD). The measurements referred to plant features determining plant quality, i.e., the number of flower buds and flower head, the diameter of the flower head, height of plants, index of leaf greenness (SPAD), the number of leaves, and the fresh and dry weights of aboveground parts of plants. The rooting of cuttings and subsequent growth are integral processes in the cultivation of potted chrysanthemums. Both were differently affected by the colour of light from LED lamps. The exposure to red + blue light resulted in the highest leaf greenness index (SPAD) value and the shortest cuttings with the longest roots. White + blue light significantly influenced most of the growth parameters, except the height of the plants and the number of leaves.

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Timing of Stolon Removal Alters Daughter Plant Production and Quality in the Ever-bearing Strawberry ‘Albion’

HortScience ◽

10.21273/hortsci15624-20 ◽

2021 ◽

pp. 1-7

Author(s):

Xiaonan Shi ◽

Ricardo Hernández ◽

Mark Hoffmann

Keyword(s):

Day Treatment ◽

Dry Weight ◽

Photosynthetic Photon Flux Density ◽

Plant Production ◽

Photon Flux ◽

Photon Flux Density ◽

Total Biomass ◽

Cultural Methods ◽

Mother Plants ◽

The Impact

Commercial strawberry (Fragaria ×ananassa Duch.) plants propagate through the development of stolons (runners) with attached daughter plants. While it is known that temperature and photoperiod affect strawberry propagation, little knowledge exists on whether cultural methods may influence stolon and daughter plant development. The objective of this study was to characterize the impact of three stolon removal treatments on the development of daughter plants in the ever-bearing strawberry ‘Albion’. Treatments included 1) stolon removal every 7 days, nine times total; 2) stolon removal every 21 days, three times total; and 3) one-time stolon removal after 63 days. Strawberry plants were grown in a controlled environment (26 °C, 507 μmol⋅m–2⋅s–1 photosynthetic photon flux density, 14-hour photoperiod) in soilless media and fertilized with a customized nutrient solution. Mother plants in the 63-day treatment produced more daughter plants (102 per plant), than in the 21-day treatment (33 per plant) and the 7-day treatment (16 per plant). In the 63-day treatment, daughter plants and stolons accumulated to 86.6% of the total biomass, to 42.9% in the 7-day treatment and to 60.6% of total biomass in the 21-day treatment. Mother plant organs (including roots, crown, and leaves) had less dry weight in the 63-day treatment compared with the 7-day treatment and 21-day treatment, respectively. Furthermore, the daughter plants produced at the 63-day treatment had smaller crown diameters (0.65 cm) and less dry weight (0.51 g) and a higher number of fully expanded leaves (2.9) and visible roots (13.4) compared with the 21-day treatment and the 7-day treatment. The results of this study show daughter plant production of strawberry plants declines significantly with shorter stolon removal intervals, indicating the need to adjust stolon removal in strawberry nurseries for optimal daughter plant production.

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Effects of soyabean leaflet inclination on some factors related to photosynthesis

The Journal of Agricultural Science ◽

10.1017/s0021859602002083 ◽

2002 ◽

Vol 138 (4) ◽

pp. 367-373 ◽

Cited By ~ 4

Author(s):

T. IKEDA ◽

R. MATSUDA

Keyword(s):

Carbon Dioxide Concentration ◽

Plant Production ◽

Physiological Adaptation ◽

Photon Flux ◽

Photon Flux Density ◽

Light Saturation ◽

Saturation Point ◽

Group Vi ◽

Solar Tracking ◽

Net Assimilation

Leaflet movement in soyabean (Glycine max (L.) Merr.) is considered to be an important physiological adaptation for intercepting sunlight for photosynthesis. Solar tracking may serve to increase plant production by maximizing light interception. The objective of this study was to determine the response of A (leaflet net assimilation rate), τ (stomatal conductance) and Ci (internal leaf carbon dioxide concentration) when penultimate fully expanded leaflet angles were changed. Soyabean (cv. Enrei, Maturity group VI) was planted at Niigata University, Japan, at two densities (25 and 16 plants/m2) in mid-May of 1992 and 1993. PFD (photon flux density), A, τ, and Ci were measured with a portable leaf photosynthesis instrument. The more towards vertical the leaflets were moved, the lower the PFD and A were. A measured at R5 showed no light saturation, but did show this at V13 and R3. While A measured at 09.00 h showed no saturation point, there was saturation at 12.00 h and 15.00 h at or less than 1500 μmol/m2/s. At R3 a high correlation (r = 0.89, P < 0.01) was found between PFD and A for naturally oriented leaflets, but not for horizontal ones. These results suggest that leaflet movement is an adaptation to optimize A.

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