Impact of Light Spectra On Plant Growth Literature Review

*sources are in alphabetical order as organized by zotero, most relevant articles starred. Some articles may not be useful so can remove those later if not used.

Key words terms (KWT)

1. light spectra AND plant growth AND impact
2. wavelength AND strawberries AND yield AND led
3. wavelength AND tomatoes AND yield AND led

Strategies

1. Searched Google Scholar using KWT1, KWT2 and KWT3
2. Found articles commonly referenced
3. Sought out source articles for specific backup

Interested in the effect of wavelength treatments (varying light quality) on the growth, yield, and nutritional value of various plants

Many methodologies, but focusing on purely LED light supply and measuring plants growth progress.

Determining the optimal lighting for plants allows for maximal value from plants (nutritional, economic) and maximal energy efficiency. This allows for self sustaining indoor growth which addresses food insecurity and sustainability concerns.

Indoor farming has been a hot research topic since the 1980's, and experienced a massive resurgence with the development of LED lighting, which offered massive benefits over previously existing lighting methods. Now research often centers around various quality treatments supplied by LEDs at specific wavelengths, and carefully tracking the growth, yield, and various content quality of the resulting plants. It is widely accepted that a large amount of red and blue light are required for ideal results, and that supplemental green and IR lights also improve the quality of the crops. Further research is being conducted on the specific biological events activated by each wavelength, as well as species' varying response to identical treatment.

Stakeholders range from indoor farming businesses (international), to sustainability organizations interested in efficient farming, to food security groups looking to solve world hunger.

• what plants prefer what wavelengths? do they all have same optimal low/high wavelength spike regions?
• impact of lighting hours - we don't do this but lots of other studies consider it so note that 24h lighting will have an effect on growth speed and final results which may differ form current literature.
• typ. distance for actual intensity received by each type of plant - consider changes as it gets larger?

[2] L. P. Oliver, S. D. Coyle, L. A. Bright, R. C. Shultz, J. V. Hager, and J. H. Tidwell, “Comparison of Four Artificial Light Technologies for Indoor Aquaponic Production of Swiss Chard, Beta vulgaris , and Kale, Brassica oleracea ,” J World Aquaculture Soc, vol. 49, no. 5, pp. 837–844, Oct. 2018, doi: 10.1111/jwas.12471.

Abstract

             To date, most aquaponic research has been conducted outdoors in tropical climates or in greenhouses in subtropical climates. For more northerly latitudes, aquaponic production will require supplemental light in greenhouses or insulated buildings. Two separate 3‐wk growth trials were conducted to evaluate the effects of four different lighting technologies on the growth of Swiss chard, Beta vulgaris  (Trial 1) and kale, Brassica oleracea (Trial 2) in aquaponic systems. Light technologies evaluated included fluorescent (FLO), metal halide (MH), induction (IND), and light‐emitting diode (LED). Four 1175‐L systems were used with all four light types represented in each system in a complete block design. Juvenile Nile tilapia, Oreochromis niloticus (241 g) were stocked in each system and fed a floating 32% protein diet at a rate of 60 g/m2 of plant grow space per day. In Trial 1, Swiss chard plants grown under LED lights for 3 wk achieved significantly higher (P ≤ 0.05) average individual weights (117.7 g), higher production per unit of area (3535 g/m2), and higher production per unit of energy (32.3 g/m2/kwh) than Swiss chard grown under the other three light types, which did not differ significantly (P> 0.05) from each other. In Trial 2, kale grown under LED lights achieved significantly higher (P≤ 0.05) average individual weights (102.9 g), higher production per unit of area (2136.6 g/m), and higher production per unit of energy (381.5 g/m2/kwh) than kale grown under the other three light types, which did not differ significantly (P> 0.05). The results of the two trials are in agreement and indicate that LED lights were superior to MH, FLO, and IND lights in terms of absolute plant growth as well as growth per unit of energy consumed. aquaponics so slightly different - they grow fish!

• LEDs achieved higher weight and production for chard and kale
• root:shoot ratio? indicator of plant health
• basically in favour of LEDs over any other type of lighting

[3] M. Navvab, “DAYLIGHTING ASPECTS FOR PLANT GROWTH IN INTERIOR ENVIRONMENTS,” vol. 17, no. 1.

This study reports on the daylighting design for plants within interior spaces. Plants are as much a part of the architectural design of today's interior design as are lighting and furniture. Most daylight buildings are designed with permanent spaces for plants. The types of plants and the conditions of their placement in each space should be evaluated at an early stage of the design process. This paper describes the effects of lighting and daylighting design, particularly dynamics of daylight for its intensity and spectral characteristics impact on plants. The basic factors in plant lighting are discussed. The architectural design application of how glazing systems contribute to plant growth and could be integrated with the lighting system design is introduced.

• discusses optimal conditions for various plants (humidity, soil, and of course lighting)
• more focused on combination of sun and additional indoor lighting, but provides guidelines for optimal illumination.

[4] K. Hidaka et al., “Effect of Supplemental Lighting from Different Light Sources on Growth and Yield of Strawberry,” Environmental Control in Biology, vol. 51, no. 1, pp. 41–47, 2013, doi: 10.2525/ecb.51.41.

Although supplemental lighting has been successfully used to boost greenhouse vegetable production, it has not found wide application in forced strawberry cultivation. In this study, we examined the effect of supplemental lighting from two different light sources on strawberry growth and yield. Strawberry plants were exposed to LED or fluorescent lamp illumination for 12 h (6:00–18:00) daily from January to April. Under LED illumination, PPFD values greater than 400 μmol m ⁻² s ⁻¹ were recorded at leaf heights of 10–30 cm, and leaf photosynthetic rates in plants exposed to LED supplemental lighting were much higher than in controls and plants exposed to fluorescent light. This accelerated photosynthesis promoted plant growth, as manifested by increases in leaf dry matter production, leaf area, and specific leaf weight, leading in turn to significant increases in average fruit weight, number of fruits, and marketable yield. The higher yields observed in LED-exposed plants compared with those under fluorescent lamp illumination were due to comparatively higher LED light intensities. Fruit soluble solids content, an index of sweetness, also increased under LED lighting. These results suggest that supplemental lighting using higher irradiance LED is an effective method for high yield production during forced strawberry cultivation.

• Photosynthetic rates increase rapidly as light intensity increased
• height per fruit higher with LED lighting than fluorescent lighting

[5] C. Miao et al., “Effects of Light Intensity on Growth and Quality of Lettuce and Spinach Cultivars in a Plant Factory,” Plants, vol. 12, no. 18, p. 3337, Sep. 2023, doi: 10.3390/plants12183337.

The decreased quality of leafy vegetables and tipburn caused by inappropriate light intensity are serious problems faced in plant factories, greatly reducing the economic benefits. The purpose of this study was to comprehensively understand the impact of light intensity on the growth and quality of different crops and to develop precise lighting schemes for specific cultivars. Two lettuce (Lactuca sativa L.) cultivars—Crunchy and Deangelia—and one spinach (Spinacia oleracea L.) cultivar—Shawen—were grown in a plant factory using a light-emitting diode (LED) under intensities of 300, 240, 180, and 120 μmol m⁻² s⁻¹, respectively. Cultivation in a solar greenhouse using only natural light (NL) served as the control. The plant height, number of leaves, and leaf width exhibited the highest values under a light intensity of 300 μmol m⁻² s⁻¹ for Crunchy. The plant width and leaf length of Deangelia exhibited the smallest values under a light intensity of 300 μmol m⁻² s⁻¹. The fresh weight of shoot and root, soluble sugar, soluble protein, and ascorbic acid contents in the three cultivars increased with the increasing light intensity. However, tipburn was observed in Crunchy under 300 μmol m⁻² s⁻¹ light intensity, and in Deangelia under both 300 and 240 μmol m⁻² s⁻¹ light intensities. Shawen spinach exhibited leaf curling under all four light intensities. The light intensities of 240 and 180 μmol m⁻² s⁻¹ were observed to be the most optimum for Crunchy and Deangelia (semi-heading lettuce variety), respectively, which would exhibit relative balance growth and morphogenesis. The lack of healthy leaves in Shawen spinach under all light intensities indicated the need to comprehensively optimize cultivation for Shawen in plant factories to achieve successful cultivation. The results indicated that light intensity is an important factor and should be optimized for specific crop species and cultivars to achieve healthy growth in plant factories.

• there is such thing as too much light, and that threshold depends on the type of plant
• use photosynthetic performance index as the indicator of health
• increased intensity of light is very good for lettuce (and possibly other leafy plants as well)

[6] L. Zha and W. Liu, “Effects of light quality, light intensity, and photoperiod on growth and yield of cherry radish grown under red plus blue LEDs,” Hortic. Environ. Biotechnol., vol. 59, no. 4, pp. 511–518, Aug. 2018, doi: 10.1007/s13580-018-0048-5.

Abstract

For more plant species to be suitable for plant factory production, their optimal light regimes need to be optimized. We evaluated the effects of light quality, light intensity, and photoperiod on the growth and yield of cherry radish grown under red plus blue LEDs in a controlled environment. Radish plants were cultivated under two light qualities with different red:blue ratios (1R:1B, 2R:1B) at three light intensities (180, 240, 300 μmol m−2 s−1) or two photoperiods (12 h/12 h, 16 h/8 h), respectively. The light quality 2R:1B increased root diameter, root volume, and the biomass of shoot and root compared to light quality 1R:1B under a light intensity of 240 and 300 μmol m−2 s−1, but the growth differences between 1R:1B and 2R:1B were significant when the light intensity was 240 μmol m−2 s−1. New leaf chlorophyll content, root growth indices and the root-shoot ratio increased with light intensity. Cherry radish only formed storage roots with commercial value when light intensity was equal to or over 240 μmol m−2 s−1. The root diameter, root volume, root-shoot ratio, and the biomass of shoot and root of plants grown in the 2R:1B treatment was significantly higher than those in the 1R:1B treatment under the 16 h/8 h photoperiod. However, no significant difference was observed in the 12 h/12 h photoperiod. These results indicated that light regime in combination with a light intensity between 240 and 300 μmol m−2 s−1, the light quality 2R:1B, and a 16 h/8 h photoperiod produced appropriate growth of cherry radish in plant factory settings using an LED light source. In conclusion, the production of commercial storage roots in cherry radish is primarily dependent on light intensity, followed by light quality and photoperiod. Furthermore, the effectiveness of light quality regulation of storage roots was highly depended on light intensity and photoperiod.

• investigate red/blue
• cherry radish production depends primarily on light intensity, then light quality
• couple references of root veg production
• references some articles for reduced benefit of 24h photoperiod
• difference in chlorophyll for new leaves not old ones - and longer photoperiod increased chlorophyll content so may see discrepancies from lit on those results
• ref study that says radish okay under red light only - thats what we see too!
• radishes like red more than blue!

[7] H. Yoshida, D. Mizuta, N. Fukuda, S. Hikosaka, and E. Goto, “Effects of varying light quality from single-peak blue and red light-emitting diodes during nursery period on flowering, photosynthesis, growth, and fruit yield of everbearing strawberry,” Plant Biotechnology, vol. 33, no. 4, pp. 267–276, 2016, doi: 10.5511/plantbiotechnology.16.0216a.

We studied the effects of varying light quality on the flowering, photosynthetic rate and fruit yield of everbearing strawberry plants (Fragaria×ananassa Duch. ‘HS138’), which are long-day plants, to increase the efficiency of fruit production in plant factories. The plants were grown under continuous lighting using three types of blue and red LEDs (blue light peak wavelength: 405, 450, and 470 nm; red light peak wavelength: 630, 660, and 685 nm) during the nursery period. All blue light from the various peak LED types promoted more flowering compared with red light (630 and 660 nm except for 685 nm). The longer wavelength among the red light range positively correlated with earlier flowering, whereas the number of days to anthesis did not significantly differ among blue LED treatment wavelengths, irrespective of peak wavelength. The result of a similar experiment using the perpetual flowering Fragaria vesca accession Hawaii-4 representing a model strawberry species showed almost the same pattern of flowering response to light quality. These results suggest that long-day strawberry plants show similar flowering response to light quality. The photosynthetic rate under red light (660 nm) was higher than that under blue light (450 nm). However, the plants grown under red light showed lower photosynthetic capacity than those grown under blue light. Although the light color used to grow the seedlings showed no difference in the daily fruit production, blue light irradiation during the nursery period hastened harvesting because of the advance in flowering.

• investigated effect of varying light quality on flowering, photosynthetic rate, and yield
• blue light promotes flowering
• small (20-40nm) differences in wavelength impact photosynthetic rate and growth (Goto 2013 - investigate this article!)
• increased number of buds in red light, likely due to more leaves
• photosynthetic ability decreased under just red light.

[8] H. D. S. S. Guiamba et al., “Enhancement of photosynthesis efficiency and yield of strawberry (Fragaria ananassa Duch.) plants via LED systems,” Front. Plant Sci., vol. 13, p. 918038, Sep. 2022, doi: 10.3389/fpls.2022.918038.

Due to advances in the industrial development of light-emitting diodes (LEDs), much research has been conducted in recent years to get a better understanding of how plants respond to these light sources. This study investigated the effects of different LED-based light regimes on strawberry plant development and performance. The photosynthetic pigment content, biochemical constituents, and growth characteristics of strawberry plants were investigated using a combination of different light intensities (150, 200, and 250 μmol m⁻² s⁻¹), qualities (red, green, and blue LEDs), and photoperiods (14/10 h, 16/8 h, and 12/12 h light/dark cycles) compared to the same treatment with white fluorescent light. Plant height, root length, shoot fresh and dry weight, chlorophyll a, total chlorophyll/carotenoid content, and most plant yield parameters were highest when illuminated with LM7 [intensity (250 μmol m⁻² s⁻¹) + quality (70% red/30% blue LED light combination) + photoperiod (16/8 h light/dark cycles)]. The best results for the effective quantum yield of PSII photochemistry Y(II), photochemical quenching coefficient (qP), and electron transport ratio (ETR) were obtained with LM8 illumination [intensity (250 μmol m⁻² s⁻¹) + quality (50% red/20% green/30% blue LED light combination) + photoperiod (12 h/12 h light/dark cycles)]. We conclude that strawberry plants require prolonged and high light intensities with a high red-light component for maximum performance and biomass production.

• invested LED based light intensities across the spectrum (qualities), AND photoperiods (light/dark cycles)
• orthogonal method to combine/analyze impacts of each parameter.

[9] N. Yeh and J.-P. Chung, “High-brightness LEDs—Energy efficient lighting sources and their potential in indoor plant cultivation,” Renewable and Sustainable Energy Reviews, vol. 13, no. 8, pp. 2175–2180, Oct. 2009, doi: 10.1016/j.rser.2009.01.027.

The rapid development of optoelectronic technology since mid-1980 has significantly enhanced the brightness and efficiency of light-emitting diodes (LEDs). LEDs have long been proposed as a primary light source for space-based plant research chamber or bioregenerative life support systems. The raising cost of energy also makes the use of LEDs in commercial crop culture imminent. With their energy efficiency, LEDs have opened new perspectives for optimizing the energy conversion and the nutrient supply both on and off Earth. The potentials of LED as an effective light source for indoor agricultural production have been explored to a great extent. There are many researches that use LEDs to support plant growth in controlled environments such as plant tissue culture room and growth chamber. This paper provides a brief development history of LEDs and a broad base review on LED applications in indoor plant cultivation since 1990.

• history of LED use for indoor applications (1990 - 2009)
• good for comparison/verification of results generally
• only covers red/blue I think, will need a different reference for the importance/effect of including green
• spectral quality may alter plant disease development [20] tracks cause noticing wayyy more algae on the control vs other walls
• kinda focused on future expansion of LED use

[10] H. Anum, R. Cheng, and Y. Tong, “Improving plant growth, anthocyanin production and oxidative status of red lettuce (Lactuca sativa cv. Lolla Rossa) by optimizing red to blue light ratio with a constant green light fraction in a plant factory,” Scientia Horticulturae, vol. 338, p. 113832, Dec. 2024, doi: 10.1016/j.scienta.2024.113832.

Previous studies have reported contrasting effects of light quality on plant growth and anthocyanin content in lettuce leaves. This study aimed to optimize the red-to-blue light ratio with a constant green light fraction to improve biomass and anthocyanin production in red lettuce (Lactuca sativa cv. ‘Lolla Rossa’) in a plant Factory. Six treatments with varying proportions of red (R, 660 nm) and blue (B, 450 nm), along with a constant fraction of green (G, 540 nm) light, recorded as R125:B25:G50, R120:B30:G50, R112:B37:G50, R100:B50:G50, R75:B75:G50, and R50:B100:G50 were set up in this study. The total photosynthetic photon flux density for all treatments was 200 μmol m 2 s 1 with a green light intensity of 50 μmol m 2 s 1. The results showed that, compared with treatment R50:B100:G50, the fresh and dry weights, leaf length, leaf area and stem width of lettuce plants under treatment R125:B25:G50 showed an increase of 73.4 %, 47.8 %, 35.5 %, 54.9 %, and 58.3 %, respectively. Additionally, red light was found to promote increased weight of lettuce plant roots. Further, the anthocyanin content, nitrate content, and stomata density under treatment R50:B100:G50 were 6.75, 1.5, and 1.42 times higher than those under treatment R125:B25:G50. Enzymatic activities such as hydrogen peroxide (H2O2), superoxide dismutase (SOD), ascorbic acid (AsA), and anthocyanin concentration per fresh weight of plant were higher under treatment R100:B50:G50, comparing with those under treatment R125:B25:G50. The above results indicate that a higher red-to-blue light ratio enhances plant biomass, photosynthesis, and certain nutrients, while increasing the blue ratio promotes anthocyanin accumulation and antioxidants, protecting cells from oxidative stress. Based on this analysis, treatment R100:B50:G50 can be considered as the suitable light spectrum for optimal growth, anthocyanin accumulation and antioxidant activity of lettuce plants. Further researches are needed to explain these effects and refine lighting methods for optimal lettuce production and nutritional quality.

red lettuce - we have that

vary red and blue w constant green.

total photosynthetic photon flux density 200umolm^-2s^-1 based on ratios

red light improves biomass photosynthesis and nutrients

blue light promotes anthocyuanin accumulation and antioxidants - R100B50G50 is suitable of optimal growth *compare to FSSC light proportions

• goes into detail about what each wavelength of light does in plants
• increase chlorophyll content with higher red to blue
• higher red also increased surgar content
• look into ulian et al 2020 - food security
• red light increased overall leaf size
• basil - krishna et all 2023
• tomato - wang et all 2022
• increased chlorophyll typically is associated with enhanced growth rates and greater photosynthetic capacity (can produce more energy to grow)
• cute lil graphic summary there to summarize the bio side of things

[11] M. Olle and I. Alsiņa, “Influence of Wavelength of Light on Growth, Yield and Nutritional Quality of Greenhouse Vegetables,” Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences., vol. 73, no. 1, pp. 1–9, Mar. 2019, doi: 10.2478/prolas-2019-0001.

All previous reviews of research on light-emitting diodes (LEDs) have been focused on how different light spectra generally influence plant yield and quality. There are no or almost no reviews on the effect of spectra on sugars or pigment concentration, or yield and growth etc. The role of visible light in food production, as in agriculture and horticulture, is obvious, as light drives photosynthesis, which is crucial for plant growth and development. Solid state lighting using LEDs represents a fundamentally different technology from gaseous discharge-type lamps currently in use. LEDs are important lamp types because the concentration of the light spectrum they emit can be changed to provide plants at various developmental stages with the light spectrum needed. A great deal of studies have been done on the effect of wavelengths of light on growth, yield and nutritional quality of greenhouse vegetables. However, little is known about the mechanisms by which the spectra affect sugar and pigment concentration, and yield, and growth. This article provides a list of how spectra influence the yield, growth, and nutritional quality of greenhouse-grown vegetables. Based on the given information we can conclude that blue, green, and red light are the main light colours that influence positively plant yield, growth and nutrient quality. Sometimes in specific situations, some other light colours are also beneficial, like far red light, orange light and UVA light. Future work on light colour manipulation has potential for producing lamps and greenhouse covers that better support plant yield, growth, and nutrition.

background of light receptors and their acutal physiological role, that is, the mechanisms by which plant growth is impacted

• note we are only focussing on “visible light”
• far red: total biomass and elongation (other articles that prove this)
• red light: reduces nitrate while increasing vitamin c (increases yield somehow) (other articles on this)
• green: promotes growth and increases saccharides while reducing nitrate concentration - only benefits
• blue: increases pigment concentration

def a great resource to confirm results, tons and tons of papers referenced

[12] D. Singh, C. Basu, M. Meinhardt-Wollweber, and B. Roth, “LEDs for energy efficient greenhouse lighting,” Renewable and Sustainable Energy Reviews, vol. 49, pp. 139–147, Sep. 2015, doi: 10.1016/j.rser.2015.04.117.

Light energy is an important factor for plant growth. In regions where the natural light source (solar radiation) is not sufficient for growth optimization, additional light sources are being used. Traditional light sources such as high pressure sodium lamps and other metal halide lamps are not very efficient and generate high radiant heat. Therefore, new sustainable solutions should be developed for energy efficient greenhouse lighting. Recent developments in the field of light source technologies have opened up new perspectives for sustainable and highly efficient light sources in the form of LEDs (light-emitting diodes) for greenhouse lighting. This review focuses on the potential of LEDs to replace traditional light sources in the greenhouse. In a comparative economic analysis of traditional vs. LED lighting, we show that the introduction of LEDs allows reduction of the production cost of vegetables in the long-run (several years), due to the LEDs’ high energy efficiency, low maintenance cost and longevity. In order to evaluate LEDs as a true alternative to current lighting sources, species specific plant response to different wavelengths is discussed in a comparative study. However, more detailed scientific studies are necessary to understand the effect of different spectra (using LEDs) on plants physiology. Technical innovations are required to design and realize an energy efficient light source with a spectrum tailored for optimal plant growth in specific plant species.

• comparative economic analysis in favour of LEDs in general - prove lower cost by proving species specific plant response to different wavelengths discuss broadband vs specific wavelengths? probably need to cite the FSSC results use these definitions of wavelength sections? wavelengths may have uneven effects depending on species (cite this!) again has lots of resources for confirmation and review (various effects across various applications and plant varieties) do we care about pr pfr conversions this has come up in several things and idk what it is ref [61] talks about spatial distribution, should look into this?

[13] N. Danziger and N. Bernstein, “Light matters: Effect of light spectra on cannabinoid profile and plant development of medical cannabis (Cannabis sativa L.),” Industrial Crops and Products, vol. 164, p. 113351, Jun. 2021, doi: 10.1016/j.indcrop.2021.113351.

Light is a key factor affecting plant growth, metabolism and function. Metabolic processes in plants are sensitive to the ratio of Blue:Red light, and there is an increasing awareness that the response to the ratio of these monochromatic lights may vary under exposure to a wider range of the spectrum, such as white light. Due to the potential for regulation of the therapeutic chemical profile and plant development, this issue is of growing interest for the cannabis (Cannabis sativa L.) industry that uses photosynthetic light extensively. Cannabis is a medicinal plant treasured for its secondary metabolites, especially cannabinoids, the unique biologically active compounds in the plant that are considered to be affected by light spectra. In this study we evaluated the hypothesis that the ratio of Blue:Red light affects cannabinoid metabolism, and that plant growth and secondary metabolism is intensified under a full spectrum with similar Blue:Red ratio. Our results point to several spectra specific reactions and some cultivar dependent responses to light spectrum. i. Yield quantity: The highest inflorescence yields were obtained when the spectrum was restricted to the red and blue range at the ratio of 1:1, and in two of the three varieties tested a ratio of 1:4 Blue:Red light had similar results. White light with Blue:Red ratio of 1:1 had the lowest yield. ii. The chemical profile was also affected by the light spectrum, and CBGA, the primary cannabinoid and a precursor for most other cannabinoids, demonstrated the highest response. CBGA accumulation was stimulated by blue-rich light as compared with far-red rich HPS light. The major cannabinoids CBDA, THCA and CBCA were also affected by light quality, and the response was cultivar specific and less pronounced than for CBGA. iii. Plant morphology: Blue light was most inductive for maintaining compact plants, more so than Red:Far-Red ratio. Our results repute the hypothesis that full spectrum improves inflorescence yield compared with Blue:Red light, but support the hypothesis that light spectrum influences plant development and the cannabinoid profile, which could be used to fine-tune cannabis and cannabinoid production.

• this is about one specific plant, could come back to this not sure if this is gonna be the most helpful?

[14] L. F. Pérez-Romero, P. J. Stirling, and R. D. Hancock, “Light-Emitting Diodes improve yield, quality and inhibitory effects on digestive enzymes of strawberry,” Scientia Horticulturae, vol. 332, p. 113192, Jun. 2024, doi: 10.1016/j.scienta.2024.113192.

Strawberries are a widely consumed fruit that are increasingly popular due to the perceived health benefits associated with their consumption. Fruit quality is highly dependent on the growing environment where light is one of the most significant environmental factors influencing plant physiology and metabolism. In the present work we sought to test the hypothesis that manipulation of the light environment in a commercial growing environment would influence fruit yield and quality. Fruit were grown with supplemental light-emitting diodes in the red (623 nm), far-red (727 nm) and blue (470 nm) regions of the spectrum at three different densities. The majority of light treatments resulted in increased fruit yield. All treatments also significantly enhanced contents of anthocyanins and polyphenols. Furthermore fruit exhibited enhanced antioxidant activity. Individual strawberry sugars showed differences depending on sampling date whereas Brix, acidity and ascorbic acid was not affected by the LED lights. Strawberry fruit extracts from all treatments exhibited the capacity to inhibit the digestive enzymes pancreatic lipase and α-amylase activity in vitro, extract from fruit grown under supplemental lighting had a greater inhibitory capacity. These data suggest that strawberry fruit grown in the presence of supplemental light may impart health benefits via enhanced functional compounds and by limiting calorific assimilation. The findings of this study provide the first evidence that the use of light-emitting diodes increase the inhibitory effects of polyphenols on digestive enzymes in strawberry.

• about strawberries so save for later

[15] E. Goto, H. Matsumoto, Y. Ishigami, S. Hikosaka, K. Fujiwara, and A. Yano, “MEASUREMENTS OF THE PHOTOSYNTHETIC RATES IN VEGETABLES UNDER VARIOUS QUALITIES OF LIGHT FROM LIGHT-EMITTING DIODES,” Acta Hortic., no. 1037, pp. 261–268, May 2014, doi: 10.17660/ActaHortic.2014.1037.30.

• haven't been able to access this yet but is referenced in almost every paper to come out after it so want to see

[16] C. Piovene et al., “Optimal red:blue ratio in led lighting for nutraceutical indoor horticulture,” Scientia Horticulturae, vol. 193, pp. 202–208, Sep. 2015, doi: 10.1016/j.scienta.2015.07.015.

In recent years, the interest toward the applicability of Light-Emitting Diode (LED) lights for indoor cultivation has significantly grown. The present work addressed the physiological and phytochemical plant responses to LED lights in indoor cultivation of leafy and fruit vegetable crops (namely sweet basil, Ocimum basilicum L.; and strawberry, Fragaria × Ananassa), with the final aim of improving both productivity and nutritional quality. Artificial light treatments were applied in a multi-sectorial growth chamber equipped with lamps with different light incidence and spectra (with red:blue ratio ranging 0.7–5.5). In all experiments, increased plant biomass, fruit yield and energy use efficiency (EUE) were associated to LED treatments, confirming the superiority of LED compared to the traditional fluorescent lamps. Interestingly, LED lighting enabled to increase antioxidant compounds and reduce nitrates content in basil leaves. A spectral red:blue ratio of 0.7 was necessary for proper plant development and improved nutraceutical properties in both crops.

best ratio for plant development (leafy fruit and vegetable) blue:red = 0.7 but better to have more green in it (CK in this study)

priority reducing nitrates for health reasons

note things like lamp distance, area of each section, product info of the lights (for overall power consumption like)

insufficient blue light fraction leads to less flowering than less fruit for fruits (wait but I don’t have any of those)

rest of this is about the neutraceutical properties

[17] D. Loconsole, G. Cocetta, P. Santoro, and A. Ferrante, “Optimization of LED Lighting and Quality Evaluation of Romaine Lettuce Grown in An Innovative Indoor Cultivation System,” Sustainability, vol. 11, no. 3, p. 841, Feb. 2019, doi: 10.3390/su11030841.

In recent years, the interest toward the applicability of Light-Emitting Diode (LED) lights for indoor cultivation has significantly grown. The present work addressed the physiological and phytochemical plant responses to LED lights in indoor cultivation of leafy and fruit vegetable crops (namely sweet basil, Ocimum basilicum L.; and strawberry, Fragaria × Ananassa), with the final aim of improving both productivity and nutritional quality. Artificial light treatments were applied in a multi-sectorial growth chamber equipped with lamps with different light incidence and spectra (with red:blue ratio ranging 0.7–5.5). In all experiments, increased plant biomass, fruit yield and energy use efficiency (EUE) were associated to LED treatments, confirming the superiority of LED compared to the traditional fluorescent lamps. Interestingly, LED lighting enabled to increase antioxidant compounds and reduce nitrates content in basil leaves. A spectral red:blue ratio of 0.7 was necessary for proper plant development and improved nutraceutical properties in both crops.

• good figures
• a lot of cycles very convoluted methodology

[18] J.-H. Jou et al., “Plant Growth Absorption Spectrum Mimicking Light Sources,” Materials, vol. 8, no. 8, pp. 5265–5275, Aug. 2015, doi: 10.3390/ma8085240.

Plant factories have attracted increasing attention because they can produce fresh fruits and vegetables free from pesticides in all weather. However, the emission spectra from current light sources significantly mismatch the spectra absorbed by plants. We demonstrate a concept of using multiple broad-band as well as narrow-band solid-state lighting technologies to design plant-growth light sources. Take an organic light-emitting diode (OLED), for example; the resulting light source shows an 84% resemblance with the photosynthetic action spectrum as a twin-peak blue dye and a diffused mono-peak red dye are employed. This OLED can also show a greater than 90% resemblance as an additional deeper red emitter is added. For a typical LED, the resemblance can be improved to 91% if two additional blue and red LEDs are incorporated. The approach may facilitate either an ideal use of the energy applied for plant growth and/or the design of better light sources for growing different plants.

• more about filters etc but kinda have our lighting figured out already

[19] E. Appolloni, F. Orsini, G. Pennisi, X. Gabarrell Durany, I. Paucek, and G. Gianquinto, “Supplemental LED Lighting Effectively Enhances the Yield and Quality of Greenhouse Truss Tomato Production: Results of a Meta-Analysis,” Front. Plant Sci., vol. 12, p. 596927, Apr. 2021, doi: 10.3389/fpls.2021.596927.

Intensive growing systems used for greenhouse tomato production, together with light interception by cladding materials or other devices, may induce intracanopy mutual shading and create suboptimal environmental conditions for plant growth. There are a large number of published peer-reviewed studies assessing the effects of supplemental light-emitting diode (LED) lighting on improving light distribution in plant canopies, increasing crop yields and producing qualitative traits. However, the research results are often contradictory, as the lighting parameters (e.g., photoperiod, intensity, and quality) and environmental conditions vary among conducted experiments. This research presents a global overview of supplemental LED lighting applications for greenhouse tomato production deepened by a meta-analysis aimed at answering the following research question: does supplemental LED lighting enhance the yield and qualitative traits of greenhouse truss tomato production? The meta-analysis was based on the differences among independent groups by comparing a control value (featuring either background solar light or solar + HPS light) with a treatment value (solar + supplemental LED light or solar + HPS + supplemental LED light, respectively) and included 31 published papers and 100 total observations. The meta-analysis results revealed the statistically significant positive effects (p-value < 0.001) of supplemental LED lighting on enhancing the yield (+40%), soluble solid (+6%) and ascorbic acid (+11%) contents, leaf chlorophyll content (+31%), photosynthetic capacity (+50%), and leaf area (+9%) compared to the control conditions. In contrast, supplemental LED lighting did not show a statistically significant effect on the leaf stomatal conductance (p-value = 0.171). In conclusion, in addition to some partial inconsistencies among the considered studies, the present research enables us to assert that supplemental LED lighting ameliorates the quantitative and qualitative aspects of greenhouse tomato production.

[20] C. Vatistas, D. D. Avgoustaki, G. Monedas, and T. Bartzanas, “The effect of different light wavelengths on the germination of lettuce, cabbage, spinach and arugula seeds in a controlled environment chamber,” Scientia Horticulturae, vol. 331, p. 113118, May 2024, doi: 10.1016/j.scienta.2024.113118.

haven't been able to ac

[21] A. A. Alrajhi et al., “The Effect of LED Light Spectra on the Growth, Yield and Nutritional Value of Red and Green Lettuce (Lactuca sativa),” Plants, vol. 12, no. 3, p. 463, Jan. 2023, doi: 10.3390/plants12030463.

Controlled Environment Agriculture (CEA) is a method of increasing crop productivity per unit area of cultivated land by extending crop production into the vertical dimension and enabling year-round production. Light emitting diodes (LED) are frequently used as the source of light energy in CEA systems and light is commonly the limiting factor for production under CEA conditions. In the current study, the impact of different spectra was compared with the use of white LED light. The various spectra were white; white supplemented with ultraviolet b for a week before harvest; three combinations of red/blue lights (red 660 nm with blue 450 nm at 1:1 ratio; red 660 nm with blue 435 nm 1:1 ratio; red 660 nm with blue at mix of 450 nm and 435 nm 1:1 ratio); and red/blue supplemented with green and far red (B/R/G/FR, ratio: 1:1:0.07:0.64). The growth, yield, physiological and chemical profiles of two varieties of lettuce, Carmoli (red) and Locarno (green), responded differently to the various light treatments. However, white (control) appeared to perform the best overall. The B/R/G/FR promoted the growth and yield parameters in both varieties of lettuce but also increased the level of stem elongation (bolting), which impacted the quality of grown plants. There was no clear relationship between the various physiological parameters measured and final marketable yield in either variety. Various chemical traits, including vitamin C content, total phenol content, soluble sugar and total soluble solid contents responded differently to the light treatments, where each targeted chemical was promoted by a specific light spectrum. This highlights the importance of designing the light spectra in accordance with the intended outcomes. The current study has value in the field of commercial vertical farming of lettuce under CEA conditions.

photoreceptors explain why species react differently to various wavelengths [9 10]

excellent structure outlining wavelength purpose with backup

discuss statistical analysis!

[22] A. Brazaitytė et al., “The effect of light-emitting diodes lighting on the growth of tomato transplants”.

The objective of our studies was to evaluate the growth of tomato transplants, cultivated under various combinations of light-emitting diodes and high-pressure sodium (HPS) lamps. The transplants of tomato hybrid ‘Raissa F1’ were grown in phytotron chambers. Day/night temperature till germination was 23°C, and a 14-h photoperiod was maintained. After the germination, photoperiod was 18 h and the day/ night temperature was 22/18°C. A system of ive high-power solid-state lighting modules with the main 447, 638, 669 and 731 nm LEDs was used in the experiments. Supplemental LEDs of different wavelength were used in particular modules: L1 – without supplemental LEDs, L2 – 380 nm, L3 – 520 nm, L4 – 595 nm, L5 – 622 nm. For comparison, tomato transplants were grown under the illumination of high-pressure sodium lamps “SON-T Agro” (“Philips”, USA). Our investigations revealed that the growth of tomato hybrid ‘Raissa F1’ transplant was enhanced under supplemental UV (380 nm) light in the high-power solid-state lighting modules with the main blue, red and far red LEDs. Therefore such LEDs can be used in modules for the cultivation of tomato transplants and it is important for their quality. Supplemental orange (622 nm), yellow (595 nm) and green (520 nm) light was not suitable for the growth of tomato transplants. The positive effect of supplemental UV and the negative effect of orange, yellow and green light were revealed in the later growing stages of tomato transplants.

• combo LED and HPS - still organized by ppfd at a given wavelength note that most statistically significant differences became apparent later on in growth concludes that orange yellow and green are not great in later stages of tomato growth

[23] M. Olle and A. Viršile, “The effects of light-emitting diode lighting on greenhouse plant growth and quality,” AFSci, vol. 22, no. 2, pp. 223–234, Jun. 2013, doi: 10.23986/afsci.7897.

The aim of this study is to present the light emitting diode (LED) technology for greenhouse plant lighting and to give an overview about LED light effects on photosynthetic indices, growth, yield and nutritional value in green vegetables and tomato, cucumber, sweet pepper transplants. The sole LED lighting, applied in closed growth chambers, as well as combinations of LED wavelengths with conventional light sources, fluorescent and high pressure sodium lamp light, and natural illumination in greenhouses are overviewed. Red and blue light are basal in the lighting spectra for green vegetables and tomato, cucumber, and pepper transplants; far red light, important for photomorphogenetic processes in plants also results in growth promotion. However, theoretically unprofitable spectral parts as green or yellow also have significant physiological effects on investigated plants. Presented results disclose the variability of light spectral effects on different plant species and different physiological indices.

• great summary of literature of effects on various types of plants will be helpful for finding source articles
• posits that further plant-specific research is needed to make widely industrially applicable

[24] B. Matysiak and A. Kowalski, “THE GROWTH, PHOTOSYNTHETIC PARAMETERS AND NITROGEN STATUS OF BASIL, CORIANDER AND OREGANO GROWN UNDER DIFFERENT LED LIGHT SPECTRA,” asphc, vol. 20, no. 2, pp. 13–22, Apr. 2021, doi: 10.24326/asphc.2021.2.2.

Growth, morphological parameters, photosynthetic performance and nitrogen status were investigated in leafy herbs grown in light-limited time in a greenhouse under different light spectra emitted by LEDs. Fluorescence-based sensors that detect crop N status and maximum photochemical efficiency of photosystem II were used in this study. Four light treatments with the ratio of Red, Blue and White LEDs including 1) R40 + B50 + W10, 2) R70 + B20 + W10, 3) R70 + B20 + W10 + Far-Red and 4) White LEDs as control were used in this study. Dominant red light and/or white LED lights at 200 µmol m–2 s–1 at plant level and a 12 h photoperiod provided the most favourable conditions for plant growth and development compared to a high proportion of blue light (R40 + B50 + W10). However, plants grown under a high proportion of blue light had a higher chlorophyll index and nitrogen balance index (NBI) than under dominant red light treatments. Our study indicates the significant potential of fluorescence-based sensors in photobiology research as well as in the production of leafy herbs under LED lights.

• leafy herbs under LED - best biomass with at least 70% red, but high share of blue (40%) enhances chlorophyll.
• mention nitrogen content as this has a strong effect on chlorophyll content
• use of red blue ratios to investigate photosynthetic performance of various species
• definitely know plants grown under multiwavelength irradiation (or white light) show higher photosynthetic activity than plants grown under monochromatic light.
• don’t forget to discuss all the treatment conditions like pH etc
• “[Ouzounis et al. 2015, Wang et al. 2016]” (Matysiak and Kowalski, 2021, p. 19) for chlorophyll measurements

[25] C. Burattini, B. Mattoni, and F. Bisegna, “The Impact of Spectral Composition of White LEDs on Spinach (Spinacia oleracea) Growth and Development,” Energies, vol. 10, no. 9, p. 1383, Sep. 2017, doi: 10.3390/en10091383.

Light-emitting diodes (LED) are a promising light source for the cultivation of edible vegetables in greenhouses. The spectral radiation of the light sources has an impact on plants physiological parameters, as well as on morphological features. In this study the growth of spinach plants has been carried out in experimental boxes under two white LED treatments having different correlate color temperature (CCT): the cold lighting (CL) corresponded to 6500 K, while the warm lighting (WL) to 3000 K. The work was aimed to investigate the influence of the two light spectra on plant development and comparing the results. Results showed that the different lighting treatments impact differently on plant development and on growth parameters.

• spinach specific, investigating 'warm' vs 'cold' light on plant development
• cold light stimulate leaf growth adjusting growth period
• warm light allowed for the most leaf production

Insert auto-generated Zotero list

[1]

T. Pocock, “Advanced lighting technology in controlled environment agriculture,” Lighting Research & Technology, vol. 48, no. 1, pp. 83–94, Feb. 2016, doi: 10.1177/1477153515622681.

[2]

A. Muller et al., “Can soil-less crop production be a sustainable option for soil conservation and future agriculture?,” Land Use Policy, vol. 69, pp. 102–105, Dec. 2017, doi: 10.1016/j.landusepol.2017.09.014.

[3]

L. P. Oliver, S. D. Coyle, L. A. Bright, R. C. Shultz, J. V. Hager, and J. H. Tidwell, “Comparison of Four Artificial Light Technologies for Indoor Aquaponic Production of Swiss Chard, Beta vulgaris , and Kale, Brassica oleracea ,” J World Aquaculture Soc, vol. 49, no. 5, pp. 837–844, Oct. 2018, doi: 10.1111/jwas.12471.

[4]

M. Navvab, “DAYLIGHTING ASPECTS FOR PLANT GROWTH IN INTERIOR ENVIRONMENTS,” vol. 17, no. 1.

[5]

M. Johkan, K. Shoji, F. Goto, S. Hahida, and T. Yoshihara, “Effect of green light wavelength and intensity on photomorphogenesis and photosynthesis in Lactuca sativa,” Environmental and Experimental Botany, vol. 75, pp. 128–133, Jan. 2012, doi: 10.1016/j.envexpbot.2011.08.010.

[6]

K. Hidaka et al., “Effect of Supplemental Lighting from Different Light Sources on Growth and Yield of Strawberry,” Environmental Control in Biology, vol. 51, no. 1, pp. 41–47, 2013, doi: 10.2525/ecb.51.41.

[7]

Z. Bliznikas et al., “EFFECT OF SUPPLEMENTARY PRE-HARVEST LED LIGHTING ON THE ANTIOXIDANT AND NUTRITIONAL PROPERTIES OF GREEN VEGETABLES,” Acta Hortic., no. 939, pp. 85–91, Nov. 2012, doi: 10.17660/ActaHortic.2012.939.10.

[8]

H. Li, C. Tang, Z. Xu, X. Liu, and X. Han, “Effects of Different Light Sources on the Growth of Non-heading Chinese Cabbage (Brassica campestris L.),” JAS, vol. 4, no. 4, p. p262, Feb. 2012, doi: 10.5539/jas.v4n4p262.

[9]

School of Biosciences, University of Nottingham Malaysia Campus, Selangor, Malaysia, M. X. Koh, A. Singh, and School of Biosciences, University of Nottingham Malaysia Campus, Selangor, Malaysia, “Effects of LED treatments on the growth and nutritional content of lettuce (Lactuca sativa) in a hydroponic vertical farming system,” Mal J Nutr, vol. 30, no. 2, Sep. 2024, doi: 10.31246/mjn-2023-0107.

[10]

C. Miao et al., “Effects of Light Intensity on Growth and Quality of Lettuce and Spinach Cultivars in a Plant Factory,” Plants, vol. 12, no. 18, p. 3337, Sep. 2023, doi: 10.3390/plants12183337.

[11]

L. Zha and W. Liu, “Effects of light quality, light intensity, and photoperiod on growth and yield of cherry radish grown under red plus blue LEDs,” Hortic. Environ. Biotechnol., vol. 59, no. 4, pp. 511–518, Aug. 2018, doi: 10.1007/s13580-018-0048-5.

[12]

T. Mizuno, W. Amaki, and H. Watanabe, “EFFECTS OF MONOCHROMATIC LIGHT IRRADIATION BY LED ON THE GROWTH AND ANTHOCYANIN CONTENTS IN LEAVES OF CABBAGE SEEDLINGS,” Acta Hortic., no. 907, pp. 179–184, Sep. 2011, doi: 10.17660/ActaHortic.2011.907.25.

[13]

Q. Li and C. Kubota, “Effects of supplemental light quality on growth and phytochemicals of baby leaf lettuce,” Environmental and Experimental Botany, vol. 67, no. 1, pp. 59–64, Nov. 2009, doi: 10.1016/j.envexpbot.2009.06.011.

[14]

H. Yoshida, D. Mizuta, N. Fukuda, S. Hikosaka, and E. Goto, “Effects of varying light quality from single-peak blue and red light-emitting diodes during nursery period on flowering, photosynthesis, growth, and fruit yield of everbearing strawberry,” Plant Biotechnology, vol. 33, no. 4, pp. 267–276, 2016, doi: 10.5511/plantbiotechnology.16.0216a.

[15]

T. K. L. Nguyen et al., “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, vol. 11, no. 11, p. 2111, Oct. 2021, doi: 10.3390/agronomy11112111.

[16]

H. D. S. S. Guiamba et al., “Enhancement of photosynthesis efficiency and yield of strawberry (Fragaria ananassa Duch.) plants via LED systems,” Front. Plant Sci., vol. 13, p. 918038, Sep. 2022, doi: 10.3389/fpls.2022.918038.

[17]

K. Benke and B. Tomkins, “Future food-production systems: vertical farming and controlled-environment agriculture,” Sustainability: Science, Practice and Policy, vol. 13, no. 1, pp. 13–26, Jan. 2017, doi: 10.1080/15487733.2017.1394054.

[18]

N. Yeh and J.-P. Chung, “High-brightness LEDs—Energy efficient lighting sources and their potential in indoor plant cultivation,” Renewable and Sustainable Energy Reviews, vol. 13, no. 8, pp. 2175–2180, Oct. 2009, doi: 10.1016/j.rser.2009.01.027.

[19]

H. Anum, R. Cheng, and Y. Tong, “Improving plant growth, anthocyanin production and oxidative status of red lettuce (Lactuca sativa cv. Lolla Rossa) by optimizing red to blue light ratio with a constant green light fraction in a plant factory,” Scientia Horticulturae, vol. 338, p. 113832, Dec. 2024, doi: 10.1016/j.scienta.2024.113832.

[20]

M. Olle and I. Alsiņa, “Influence of Wavelength of Light on Growth, Yield and Nutritional Quality of Greenhouse Vegetables,” Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences., vol. 73, no. 1, pp. 1–9, Mar. 2019, doi: 10.2478/prolas-2019-0001.

[21]

M. G. Lefsrud, D. A. Kopsell, and C. E. Sams, “Irradiance from Distinct Wavelength Light-emitting Diodes Affect Secondary Metabolites in Kale,” horts, vol. 43, no. 7, pp. 2243–2244, Dec. 2008, doi: 10.21273/HORTSCI.43.7.2243.

[22]

C. Nájera, V. M. Gallegos-Cedillo, M. Ros, and J. A. Pascual, “LED Lighting in Vertical Farming Systems Enhances Bioactive Compounds and Productivity of Vegetables Crops,” in The 1st International Electronic Conference on Horticulturae, MDPI, Apr. 2022, p. 24. doi: 10.3390/IECHo2022-12514.

[23]

D. Singh, C. Basu, M. Meinhardt-Wollweber, and B. Roth, “LEDs for energy efficient greenhouse lighting,” Renewable and Sustainable Energy Reviews, vol. 49, pp. 139–147, Sep. 2015, doi: 10.1016/j.rser.2015.04.117.

[24]

Institute of Crop Science, Sant’Anna School of Advanced Studies of Pisa, Pisa, Italy, A. Ferrante, S. Toscano, Department of Veterinary Science, Università degli Studi di Messina, Messina, Italy, D. Romano, and Department of Agriculture, Food and Environment, Università degli Studi di Catania, Catania, Italy, “Light quality and intensity modulation on yield and quality on crops grown in vertical farms,” Europ.J.Hortic.Sci., vol. 89, no. 5, pp. 1–8, Dec. 2024, doi: 10.17660/eJHS.2024/024.

[25]

E. Goto, H. Matsumoto, Y. Ishigami, S. Hikosaka, K. Fujiwara, and A. Yano, “MEASUREMENTS OF THE PHOTOSYNTHETIC RATES IN VEGETABLES UNDER VARIOUS QUALITIES OF LIGHT FROM LIGHT-EMITTING DIODES,” Acta Hortic., no. 1037, pp. 261–268, May 2014, doi: 10.17660/ActaHortic.2014.1037.30.

[26]

N. Asgari, U. Jamil, and J. M. Pearce, “Net Zero Agrivoltaic Arrays for Agrotunnel Vertical Growing Systems: Energy Analysis and System Sizing,” Sustainability, vol. 16, no. 14, p. 6120, Jul. 2024, doi: 10.3390/su16146120.

[27]

C. Piovene et al., “Optimal red:blue ratio in led lighting for nutraceutical indoor horticulture,” Scientia Horticulturae, vol. 193, pp. 202–208, Sep. 2015, doi: 10.1016/j.scienta.2015.07.015.

[28]

D. Loconsole, G. Cocetta, P. Santoro, and A. Ferrante, “Optimization of LED Lighting and Quality Evaluation of Romaine Lettuce Grown in An Innovative Indoor Cultivation System,” Sustainability, vol. 11, no. 3, p. 841, Feb. 2019, doi: 10.3390/su11030841.

[29]

G. W. Stutte, S. Edney, and T. Skerritt, “Photoregulation of Bioprotectant Content of Red Leaf Lettuce with Light-emitting Diodes,” horts, vol. 44, no. 1, pp. 79–82, Feb. 2009, doi: 10.21273/HORTSCI.44.1.79.

[30]

E. Appolloni, F. Orsini, G. Pennisi, X. Gabarrell Durany, I. Paucek, and G. Gianquinto, “Supplemental LED Lighting Effectively Enhances the Yield and Quality of Greenhouse Truss Tomato Production: Results of a Meta-Analysis,” Front. Plant Sci., vol. 12, p. 596927, Apr. 2021, doi: 10.3389/fpls.2021.596927.

[31]

R. Sirtautas and A. Novickovas, “Supplementary red-LED lighting affects phytochemicals and nitrate of baby leaf  lettuce”.

[32]

A. Brazaitytė and A. Viršilė, “Supplementary red-LED lighting and the changes in phytochemical content of  two baby leaf lettuce varieties during three seasons”.

[33]

C. Vatistas, D. D. Avgoustaki, G. Monedas, and T. Bartzanas, “The effect of different light wavelengths on the germination of lettuce, cabbage, spinach and arugula seeds in a controlled environment chamber,” Scientia Horticulturae, vol. 331, p. 113118, May 2024, doi: 10.1016/j.scienta.2024.113118.

[34]

A. A. Alrajhi et al., “The Effect of LED Light Spectra on the Growth, Yield and Nutritional Value of Red and Green Lettuce (Lactuca sativa),” Plants, vol. 12, no. 3, p. 463, Jan. 2023, doi: 10.3390/plants12030463.

[35]

A. Brazaitytė et al., “The effect of light-emitting diodes lighting on the growth of tomato transplants”.

[36]

M. Olle and A. Viršile, “The effects of light-emitting diode lighting on greenhouse plant growth and quality,” AFSci, vol. 22, no. 2, pp. 223–234, Jun. 2013, doi: 10.23986/afsci.7897.

[37]

B. Matysiak and A. Kowalski, “THE GROWTH, PHOTOSYNTHETIC PARAMETERS AND NITROGEN STATUS OF BASIL, CORIANDER AND OREGANO GROWN UNDER DIFFERENT LED LIGHT SPECTRA,” asphc, vol. 20, no. 2, pp. 13–22, Apr. 2021, doi: 10.24326/asphc.2021.2.2.

[38]

C. Burattini, B. Mattoni, and F. Bisegna, “The Impact of Spectral Composition of White LEDs on Spinach (Spinacia oleracea) Growth and Development,” Energies, vol. 10, no. 9, p. 1383, Sep. 2017, doi: 10.3390/en10091383.

[39]

M. S. Mir et al., “Vertical farming: The future of agriculture: A review”.