Light Quality Influence on Growth Performance and Physiological Activity of Coleus Cultivars
Abstract and Figures
This study investigates the influence of different light qualities, including red, green, blue, purple, and white lights, on the growth, physiological activity, and ornamental characteristics of two Coleus cultivars. Emphasizing the importance of leveraging phenotypic plasticity in plants within controlled environments, using light quality is a practice prevalent in the ornamental industry. The research explores the varied responses of two Coleus cultivars to distinct light spectra. The key findings reveal the efficacy of red light in enhancing shoot and leaf parameters in C. ‘Highway Ruby’, while red and green light exhibit comparable effects on shoot width and leaf dimensions in C. ‘Wizard Jade’. White light-emitting diodes (LEDs), particularly with color temperatures of 4100 K and 6500 K, promote root length growth in the respective cultivars. Moreover, chlorophyll content and remote sensing vegetation indices, including chlorophyll content (SPAD units), the normalized difference vegetation index (NDVI), the modified chlorophyll absorption ratio index (MCARI), and the photochemical reflectance index (PRI), along with the chlorophyll fluorescence, were significantly affected by light qualities, with distinct responses observed between the cultivars. In summary, this study highlights the transformative potential of LED technology in optimizing the growth and ornamental quality of foliage plants like Coleus, setting a benchmark for light quality conditions. By leveraging LED technology, producers and nursery growers access enhanced energy efficiency and unparalleled versatility, paving the way for significant advancements in plant growth, color intensity, and two-tone variations. This presents a distinct advantage over conventional production methods, offering a more sustainable and economically viable approach for increased plant reproduction and growth development. Likewise, the specific benefits derived from this study provide invaluable insights, enabling growers to strategically develop ornamental varieties that thrive under optimized light conditions and exhibit heightened visual appeal and market desirability.
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... The efficiency of LED lighting lies in its ability to manipulate the spectral composition of light, which plays a pivotal role in regulating in vitro plant growth and development. Optimally selected combinations of light spectra, including red, green, blue, violet, and white light, affect physiological processes, such as photosynthesis, and morphological features, including shoot elongation, axillary shoot formation, somatic embryo induction, rhizogenesis, and leaf anatomy [33,34]. LED lighting (red, blue, infrared, and ultraviolet) had a positive impact on root system development, shoot length, number of leaves, and chlorophyll content in cultivars of plum and raspberry microplants during the ex vitro adaptation stage [35,36]. ...
... Therefore, it is difficult to identify the regularity of the influence of the LED wavelength on the content of this group of pigments. NDVI values, reflecting plant vigor and photosynthetic activity, were significantly affected by the type of LED lighting [33,48] The RWUV-A lighting (1UV:13B:33G:49R:4FR) condition resulted in the highest NDVI values across all cultivars, indicating improved physiological status (content of Chl a and Chl a + b) and biomass accumulation (biometric indicators) (Figures 3, 4 and S5, Table 6). Comparatively lower NDVI values were observed under W and RW lighting conditions (p < 0.05). ...
... These findings reinforce the advantages of the combination of red-, green-, and UV-spectrum LEDs in enhancing the adaptation efficiency of microplants to ex vitro conditions. Horticulturae 2025, 11, x FOR PEER REVIEW 12 of 19 NDVI values, reflecting plant vigor and photosynthetic activity, were significantly affected by the type of LED lighting [33,48] The RWUV-A lighting (1UV:13B:33G:49R:4FR) condition resulted in the highest NDVI values across all cultivars, indicating improved physiological status (content of Chl a and Chl a + b) and biomass accumulation (biometric indicators) (Figures 3 and 4, Figure S5, Table 6). Comparatively lower NDVI values were observed under W and RW lighting conditions (p < 0.05). ...
This study focuses on refining in vitro propagation protocols for red currant cultivars of the Ribes genus and evaluating the role of LED lighting in the adaptation of microplants. The cultivars ‘Red Lake’, ‘Englische Grosse Weisse’, ‘Marmeladnitsa’, and ‘Podarok Leta’ were successfully introduced into in vitro culture during their dormancy phase using 0.1% HgCl2 as a sterilizing agent. The period of spring introduction is not very efficient in connection with the intensive development of saprophytic microflora and weak morphogenesis microplants. Using 0.01% C9H9HgNaO2S sterilizer resulted in a decrease in the necrosis percentage, but an increase in mold proportion. The preparation of the plants with 12% H2O2 was considered environmentally not effective enough to obtain a large number of healthy microplants. The use of 12% H2O2 resulted in increased necrosis rates by 24.76% compared to 0.01% C9H9HgNaO2S and 0.1% HgCl2 sterilizers. The variety specificity of Ribesia plants in terms of the content of MS and LF nutrient media components was determined by the survival rate of explants, the formation of additional micro-shoots, and the morphological development. The MS medium with the addition of 1 mg∙L⁻¹ BAP decreased the percentage of mold and necrosis infection and provided a high percentage of viable plants with optimal growth and reproduction rate. In contrast, the LF medium with the same concentration of 6-BAP resulted in poor explant quality and leaf chlorosis at later stages. The study also investigated the effects of different LED light spectra on morphological and physiological traits. For ‘Red Lake’ and ‘Englische Grosse Weisse’, RWUV-A (625–740 nm) lighting enhanced biomass and chlorophyll (Chl a and Chl a + b) accumulation, while the White (W) spectrum benefited ‘Podarok Leta’. Conversely, the RW spectrum with minimal green and no ultraviolet light restricted growth and photosynthetic pigment accumulation across all cultivars, promoting compact plant structures. The RWUV-A lighting condition resulted in the highest NDVI values across all cultivars, indicating an improved physiological status and biomass accumulation. These findings underscore the importance of refining the microclonal reproduction protocols for Ribesia subgenus representatives, emphasizing the genotype-specific light modulation during the proliferation stage. The study highlights the utility of the MS medium and tailored light conditions in enhancing the effectiveness of propagation techniques for producing high-quality planting material.
... Artificial light sources, such as light-emitting diodes (LEDs) or fluorescent lamps, are widely used in the horticultural industry and controlled environmental agriculture for photoperiod control and supplemental lighting (Hemming, 2009;Kim et al., , 2024bLocatelli et al., 2024;Park et al., 2012). The adjustment of light quality or spectra, along with the photoperiod and light intensity, is known to directly influence plant growth and development (Park et al., 2024;Yan et al., 2019;Ye et al., 2024). Such light environment controls are primarily applied in facility-based cultivation systems, particularly in controlled environments, such as closed-type plant factories and nursery systems that are unaffected by sunlight (Choi et al., 2024;Kim and Park, 2023;Kozai, 2013). ...
... Moreover, Ranade and Gil (2016) found that blue light treatments significantly improved the quality of Scots pine (Pinus sylvestris) seedlings during germination and hypocotyl development, indicating the diverse benefits of blue light. In contrast, red or green LED lights have been reported to promote plant size increases in Coleus cultivars (Park et al., 2024), highlighting species or cultivar-specific responses to different light qualities. Consistent with the results of this study, blue light was shown to be advantageous for significantly enhancing plant size-related parameters, such as shoot and root lengths in T. ionantha, supporting previous findings that plants respond selectively to different light qualities. ...
... As shown above, each light spectrum had varying effects on the growth parameters of different organs (i.e., shoots, roots, and leaves) in T. ionantha. The regulation of light spectra is not only used to promote plant growth in facility-based cultivation and supplemental lighting in plant nurseries but has also been applied to induce the development of in vitro plantlets in tissue culture (Batista et al., 2018;Seo et al., 2022), promote the expression of unique leaf patterns (Park et al., 2024), and encourage the development of specific organs such as roots and flowers (Jang et al., 2023;Kim et al., 2024a). Generally, plants grown under monochromatic light conditions exhibit restricted growth compared with those grown under purple phyto-LED and white LEDs, which provide a broader spectral distribution (Budavári et al., 2024;Kim et al., 2024a;Shin et al., 2024). ...
In the present study, we aimed to establish an efficient cultivation method for Tillandsia ionantha, which is commonly known as an air plant and is distributed as an ornamental succulent. This species was cultivated using non-substrate cultivation methods in a controlled environment, and the influence of various light spectra on its growth was investigated. The light-emitting diode (LED) light sources used included red (630 nm), green (520 nm), blue (450 nm), purple phyto-LED (450 nm, 650 nm, and far-red wavelengths), warm white (3000 K), natural white (4100 K), and cool white (6500 K) lights. The results showed that shoot length, root length, and leaf width significantly increased under monochromatic blue LED light, highlighting its effectiveness in promoting plant size. In contrast, root and leaf numbers were most effectively enhanced under cool white LED light, highlighting the suitability of broad-spectrum light for balanced root and leaf development. Biomass analysis revealed a growth imbalance between the shoot and root parts, with root biomass being the highest under warm white and cool white LED lights. Red LED light increased relative water content in shoots, indicating its potential for enhancing water retention. Additionally, the external quality of T. ionantha, evaluated using the Commission Internationale de l’Éclairage Lab (CIELAB) color space values, revealed significant changes in leaf coloration under various light spectra. The highest L * value was observed under the natural white LED treatment, whereas the a * and b * parameters varied significantly depending on the light spectra. These findings underscore the importance of light spectrum selection in optimizing T. ionantha various parameters and suggest that a combination of monochromatic and broad-spectrum light can be used complementarily for balanced growth and external quality. This study provides foundational data for the stable cultivation of epiphytic plant species in a controlled environment facility, supporting their broader application in the ornamental plant industry and indoor horticultural projects.
... Hypothesis about the key role of the spectral area in the induction of changes in broadband RIs shows some restrictions on using these reflectance indices in plant remote sensing. Considering that the concentrations of photosynthetic pigments are dependent on the action of environmental factors [43][44][45][46][47][48][49]57,58] and that the peaks of light absorption by these pigments [59,60] can be narrower than broad bandwidths (about 100 nm), broadband RIs (as well as RGB indices) should be weakly sensitive to intricate changes in pigment content (e.g., changes in ratio between the contents of chlorophylls a and b). In contrast, specific narrowband RIs are sensitive to these changes [9] through high spectral resolution. ...
... Considering the potential role of changes in the content of photosynthetic pigments in the sensitivity (see above), it can be expected that other environmental factors should also influence RI(659, 553) and NRGI. Particularly, it is known that changes in the content of pigments can be caused by the action of salts [65,66], increased temperatures [67], light with different intensities and spectral composition [57,58,68], etc. However, this supposition requires future checking. ...
Global climatic changes increase areas that are influenced by drought. Remote sensing based on the spectral characteristics of reflected light is widely used to detect the action of stressors (including drought) in plants. The development of methods of improving remote sensing is an important applied task for plant cultivation. Particularly, this improvement can be based on the calculation of reflectance indices and revealing the optimal spectral bandwidths for this calculation. In the current work, we analyzed the sensitivity of broadband-normalized difference reflectance indices and RGB indices to the action of soil drought on pea and wheat plants. Analysis of the heat maps of significant changes in reflectance indices showed that increasing the spectral bandwidths did not decrease this significance in some cases. Particularly, the index RI(659, 553) based on the red and green bandwidths was strongly sensitive to drought action in plants. The normalized red–green index (NRGI), which was the RGB-analog of RI(659, 553) measured by a color camera, was also sensitive to drought. RI(659, 553) and NRGI were strongly related. The results showed that broadband and RGB indices can be used to detect drought action in plants.
... The limitations of the VARI index and vegetation indices are well known [30]; in the present study, they serve a representational purpose to quantify visually distinguishable differences. There are a number of studies in the literature that utilize vegetation indices for leaf color evaluation [31][32][33]. Based on the data analysis results in Table 2, the stem color groups from VARI indexes are similar to the manual observations. ...
Hemp (Cannabis sativa L.), one of the earliest domesticated crops, has diverse applications in textiles, construction, nutrition, and medicine. Breeding advancements, including speed breeding, accelerate genetic improvements in crops by optimizing environmental conditions for reduced generation times. This study employed greenhouse and field experiments to develop a proprietary yellow-stemmed hemp germplasm with a unique stem trait. Initial crossbreeding between the late Eletta Campana (medium green stems) and the early Chamaeleon (yellow stems) demonstrated the recessive monogenic inheritance of the yellow-stem trait and fast and safe stabilization even in the case of parent varieties with different flowering times. Controlled flowering in the case of photoperiod-sensitive genotypes, manual pollination, and successive backcrossing stabilized the yellow-stem trait over six cycles, with 100% trait consistency achieved by the fifth cycle within just 12 months in total. Open-field trials validated greenhouse results, showing strong correlations between visual stem color assessments and visible atmospherically resistant index (VARI) obtained through remote sensing imagery. Cannabinoid analyses indicated significant reductions in tetrahydrocannabinol (THC) content while maintaining optimal cannabidiol (CBD) levels. Accumulated growing degree days (GDDs) optimized flowering and maturity, ensuring consistency in phenological traits. This research highlights the utility of speed breeding and chemical analysis to accelerate trait stabilization and improve industrial hemp’s agronomic potential for fiber and CBD production while adhering to regulatory THC limits.
... These comparisons underscore the robustness of the chosen methodology, while also suggesting that the integration of a wider range of indices and more complex modeling approaches can improve the accuracy of crop growth predictions in precision agriculture. Remote sensing vegetation indices have been widely applied across various fields, including assessing vegetation health, monitoring environmental changes, and managing crop production under diverse conditions such as temperature extremes, water availability, and variations in light intensity or quality [58]. These indices are invaluable tools for detecting plant responses, which are often reflected through changes in pigment composition and photosynthetic efficiency. ...
Wheat is a key staple crop globally, essential for food security and sustainable agricultural development. The results of this study highlight how innovative monitoring techniques, such as UAV-based multispectral imaging, can significantly improve agricultural practices by providing precise, real-time data on crop growth. This study utilized unmanned aerial vehicle (UAV)-based remote sensing technology at the wheat experimental field of the Hebei Academy of Agriculture and Forestry Sciences to capture the dynamic growth characteristics of wheat using multispectral data, aiming to explore efficient and precise monitoring and management strategies for wheat. A UAV equipped with multispectral sensors was employed to collect high-resolution imagery at five critical growth stages of wheat: tillering, jointing, booting, flowering, and ripening. The data covered four key spectral bands: green (560 nm), red (650 nm), red-edge (730 nm), and near-infrared (840 nm). Combined with ground-truth measurements, such as chlorophyll content and plant height, 21 vegetation indices were analyzed for their nonlinear relationships with wheat growth parameters. Statistical analyses, including Pearson’s correlation and stepwise regression, were used to identify the most effective indices for monitoring wheat growth. The Normalized Difference Red-Edge Index (NDRE) and the Triangular Vegetation Index (TVI) were selected based on their superior performance in predicting wheat growth parameters, as demonstrated by their high correlation coefficients and predictive accuracy. A random forest model was developed to comprehensively evaluate the application potential of multispectral data in wheat growth monitoring. The results demonstrated that the NDRE and TVI indices were the most effective indices for monitoring wheat growth. The random forest model exhibited superior predictive accuracy, with a mean squared error (MSE) significantly lower than that of traditional regression models, particularly during the flowering and ripening stages, where the prediction error for plant height was less than 1.01 cm. Furthermore, dynamic analyses of UAV imagery effectively identified abnormal field areas, such as regions experiencing water stress or disease, providing a scientific basis for precision agricultural interventions. This study highlights the potential of UAV-based remote sensing technology in monitoring wheat growth, addressing the research gap in systematic full-cycle analysis of wheat. It also offers a novel technological pathway for optimizing agricultural resource management and improving crop yields. These findings are expected to advance intelligent agricultural production and accelerate the implementation of precision agriculture.
... For instance, a study on Coleus cultivars highlighted the efficacy of red light in enhancing shoot and leaf parameters, while white LEDs were found to promote root growth. These findings underscore the potential of LED technology to optimize plant growth under controlled environments [14]. Although existing studies have revealed the individual effects of soil moisture and light on the growth of P. notoginsen, the combined effects of light-water interactions on its growth, yield, and quality have not been thoroughly explored. ...
Panax notoginseng (Burkill) F. H. Chen, as a traditional Chinese medicinal herb with significant therapeutic effects, is highly sensitive to environmental factors during its growth process, particularly light and water conditions. Under traditional field conditions, natural limitations make it difficult to achieve optimal yield and quality. This study aimed in the past to determine the optimal light–water interaction model for the year-round cultivation of P. notoginseng in a controlled plant factory environment. The experiment used one-year-old, uniformly grown P. notoginsen seedlings. At the beginning of the experiment, the light source, without any shading treatment, provided a photosynthetically active radiation (PAR) intensity of 200 μmol·m⁻²·s⁻¹, measured at a distance of 30 cm from the plant canopy. A total of 18 treatment combinations were established, specifically two different light quality treatments (A Treatment with a red-to-blue light ratio of 4:1 and B Treatment with a red-to-blue light ratio of 5:1) were each combined with three irrigation levels (field water capacities of 40%, 50%, and 60%) and three shading levels (one layer of 60% shading net, two layers of 60% shading net, and three layers of 60% shading net). Each light quality treatment was combined with all three irrigation levels and all three shading levels, resulting in 18 distinct treatment combinations. The effects of different light–water interactions on P. notoginseng growth were evaluated by measuring key agronomic traits, chlorophyll fluorescence parameters, and ginsenoside content. The results indicate that light–water interactions significantly affect the agronomic traits, chlorophyll fluorescence parameters, and ginsenoside content of P. notoginseng (light treatment had a more significant impact on the growth of P. notoginsen than water treatment). The best performance in terms of plant height (15.3 cm), stem diameter (3.45 mm), leaf length (8.6 cm), fresh weight (3.382 g), and total ginsenoside content (3.8%) was observed when the red-to-blue light ratio was 4:1 (A Treatment), the field water capacity was 50%, and the shading level was three layers. Based on this, the Pearson correlation analysis was used to identify eight highly correlated indicators, and the entropy-weighted TOPSIS model was applied to comprehensively evaluate the cultivation schemes. The evaluation results show that the optimal cultivation scheme for P. notoginseng is under the conditions of a red-to-blue light ratio of 4:1 (A Treatment), field water capacity of 50%, and three-layer shading.
... LED lighting was more popularly used due to its energy efficiency, longevity, and ability to provide a customizable light spectrum tailored to the specific needs of different plant species [4]. Additionally, the application of LED lighting technology makes it possible to regulate the quality of light, thereby promoting plant growth and physiological activities [13]. Notably, the efficiency of blue LEDs can reach 93%, while that of red LEDs stands at 81% [14], optimizing energy efficiency while providing precise spectral control, which is critical for optimizing plant growth in controlled environments [15,16]. ...
This study examines the impact of daily light integral (DLI) from artificial lighting on tomato seedlings cultivated in plant factories. By adjusting the light intensity and photoperiod of LED, the research explored the effects of varying DLIs on the morphology, growth, physiological characteristics, photosynthetic pigment content, and chlorophyll fluorescence of tomato seedlings. The optimal DLI enhanced seedling growth, biomass, root vitality, antioxidant enzyme activity, and photosynthetic pigment synthesis. Excessively high DLI or light intensity inhibited photosynthesis, potentially leading to photoinhibition. This study identified the optimal DLI of 13.2 mol·m⁻²·d⁻¹ through varying DLI gradients in Exp 1 and Exp 2. Based on these findings, Exp 3 established the optimal growth conditions by setting different light intensities and photoperiods under the most suitable DLI, which were a light intensity of 200 μmol·m⁻²·s⁻¹ and a photoperiod of 18 h. These results provide significant guidance for optimizing the light environment in the cultivation of tomato seedlings in plant factories, helping to improve the light energy utilization efficiency.
... In the study of ornamental plants, CIELAB color space can be used to calculate and compare the brightness, chromaticity, hue, and color metrics of plant leaves at different developmental stages or under different conditions. In addition, some studies used CIELAB measurements to link physiological changes in plants with visual characteristics to accurately measure leaf color changes at different developmental stages [37,38]. We were able to observe the differences in leaf color changes between the four developmental stages of I. hawkeri 'Sakimp005' in this study. ...
One of the most important characteristics of ornamental plants is leaf color, which enhances the color of plant landscapes and attracts pollinators for reproduction. The leaves of Impatiens hawkeri ‘Sakimp005’ are initially green, then the middle part appears yellow, then gradually become white, while the edge remains green. In the study, leaves of I. hawkeri ‘Sakimp005’, in four developmental stages (S1-G, S2-C, S3-C, and S4-C), were selected for the determination of pigment content, chromaticity values, integrative metabolomics, and transcriptomics analyses. The carotenoid content of leaves varied significantly and regularly at four stages, and the colorimetric values corroborated the phenotypic observations. The results of integrative metabolomics and transcriptomics analysis show that the accumulation of two carotenoids (lutein and zeaxanthin), to different degrees in the leaves of I. hawkeri ‘Sakimp005’ at four stages, led to the vary yellowing phenomenon. We speculated that the carotenoid biosynthesis (containing two branches: α-branch and β-branch) in leaves by IhLUT1 and IhLUT5 in the α-branch and IhBCH2 genes in the β-branch differed. These findings provide a molecular basis for Impatiens plants’ leaf color breeding and improve the knowledge of the leaf color mechanism.
... For example, vegetation indices are used to assess the developmental responses of Coleus under different light qualities. Similarly, indices such as the Photochemical Reflectance Index (PRI) and the Modified Chlorophyll Absorption Ratio Index (MCARI) have demonstrated their effectiveness in characterizing the growth and developmental traits of Viola species under varying color temperatures [12,13]. Plant pigment content and spectral reflectance are closely related. ...
The pigment content of rice leaves plays an important role in the growth and development of rice. The accurate and rapid assessment of the pigment content of leaves is of great significance for monitoring the growth status of rice. This study used the Analytical Spectra Device (ASD) FieldSpec 4 spectrometer to measure the leaf reflectance spectra of 4 rice varieties during the entire growth period under 4 nitrogen application rates and simultaneously measured the leaf pigment content. The leaf’s absorption spectra were calculated based on the physical process of spectral transmission. An examination was conducted on the variations in pigment composition among distinct rice cultivars, alongside a thorough dissection of the interrelations and distinctions between leaf reflectance spectra and absorption spectra. Based on the vegetation index proposed by previous researchers in order to invert pigment content, the absorption spectrum was used to replace the original reflectance data to optimize the vegetation index. The results showed that the chlorophyll and carotenoid contents of different rice varieties showed regular changes during the whole growth period, and that the leaf absorption spectra of different rice varieties showed more obvious differences than reflectance spectra. After replacing the reflectance of pigment absorptivity-sensitive bands (400 nm, 550 nm, 680 nm, and red-edge bands) with absorptivities that would optimize the vegetation index, the correlation between the vegetation index, which combines absorptivity and reflectivity, and the chlorophyll and carotenoid contents of 4 rice varieties during the whole growth period was significantly improved. The model’s validation results indicate that the pigment inversion model, based on the improved vegetation index using absorption spectra, outperforms the traditional vegetation index-based pigment inversion model. The results of this study demonstrate the potential application of absorption spectroscopy in the quantitative inversion of crop phenotypes.
This study aimed to improve the stem-cutting propagation efficiency and morphophysiological characteristics of the variegated ornamental foliage plant Hedera algeriensis cv. Gloire de Marengo using two types of auxins and four concentrations for each type of auxinic rooting promoter tested here. The following nine concentrations were used: control; 3-indolebutyric acid (IBA) at 250, 500, 750, and 1000 mg·L-1; and 1-naphthylacetic acid (NAA) at 250, 500, 750, and 1000 mg·L-1. Plant size parameters varied with the auxinic rooting promoter concentrations, with IBA and NAA producing larger plants relative to the control. Shoot dry weight was highest at both IBA 500 mg·L-1 and NAA 500 mg·L-1, whereas root dry weight was significantly higher across all treatments compared to the control. Total dry weight followed patterns similar to the shoot dry weight. The moisture content showed no significant differences among the treatments. The Dickson quality index (DQI) was higher in all treatments except for the control, indicating improved plant quality with auxinic rooting promoters. The normalized difference vegetation index (NDVI) and maximum quantum yield (Fv/Fm) were highest at IBA 500 mg·L-1 and NAA 500 and 750 mg·L-1, indicating superior physiological responses in these treatments. The modified chlorophyll absorption ratio index (MCARI) was highest in the control treatment, while the photosynthetic performance index (PIABS) was highest in the NAA 500 mg·L-1 treatment, suggesting a lower chlorophyll content in the control and enhanced photosynthetic apparatus integrity due to the NAA 500 mg·L-1 treatment, respectively. In conclusion, NAA 500 mg·L-1 was the most effective concentration for ‘Gloire de Marengo’ stem-cutting propagation, followed by IBA 500 mg·L-1. These findings provide valuable insights into optimizing auxinic rooting promoter concentrations, offering crucial guidance for improving propagation efficiency and morphophysiological characteristics of this cultivar.
Cichorium intybus, a leafy vegetable belonging to the Asteraceae family, is known for its potential health benefits and the inclusion of various bioactive compounds and indigestible oligosaccharides that improve liver function and aid in fatigue recovery. In this study, we evaluated the effects of light-emitting diode (LED) light qualities on the growth, vegetation indices, and photosynthesis of the C. intybus cultivars ‘Asia Sugar’ and ‘Rossa Italiana’, grown in a closed nursery facility. LED light treatments included seven types of monochromatic, composite, and white LEDs (i.e., red, green, blue; purple; 3000, 4100, and 6500 K white LEDs) applied to these cultivars. The results showed that ‘Asia Sugar’ reached its largest size under the 3000 and 4100 K white LED treatments, whereas ‘Rossa Italiana’ exhibited the highest growth under the 3000 K white LED light treatment. An analysis of monochromatic light revealed that red LED light increased plant sizes and weights compared to blue LED light, and a higher distribution of red wavelengths within the white light spectrum positively influenced plant sizes and weights. With regard to increasing plant weights, both cultivars performed best under 3000 and 4100 K white LEDs, similar to the results for plant sizes. In contrast, ‘Asia Sugar’ showed the most favorable vegetation and photosynthetic indices under 4100 and 6500 K white LEDs, while the ‘Rossa Italiana’ showed the most favorable photosynthetic indices and chlorophyll content (SPAD units) under 6500 K white LED, opposite to the plant size results. These findings provide valuable insights into how specific LED light qualities can be optimized to enhance the growth and physiological responses of Cichorium intybus cultivars seedlings.
Peperomia, the commonly cultivated house plants, are known for their superior shade tolerance, and suitability as ornamental indoor plants. Here, the effects of different color temperatures of white light-emitting diodes (LEDs) were experimentally investigated on Peperomia. Three white LEDs with different color temperatures of 3000, 4100, and 6500 K, respectively, were used in the cultivation of Peperomia species and cultivars namely: P. obtusifolia, P. caperata cv. Napoli Nights (‘Napoli Nights’), and P. caperata cv. Eden Rosso (‘Eden Rosso’) for experimental purposes. Results showed that the sizes of the plants P. obtusifolia and ‘Napoli Nights’ were optimal under 4100 and 6500 K white LEDs, whereas, ‘Eden Rosso’ exhibited optimal growth under 6500 K white LED. Compared to the other plants, P. obtusifolia exhibited superior biomass production under 4100 K white LED. Conversely, ‘Eden Rosso’ and ‘Napoli Nights’ had the highest biomass under 6500 and 3000 K white LEDs, respectively. Regarding the leaf color, L* and b* values demonstrated an inverse relationship with plant biomass, suggesting that leaves turn yellow when the growth of a plant is inhibited. Fv/Fm ranged from 0.77 to 0.81 across all treatments, and these values are generally acceptable. Compared to the other plants, P. obtusifolia and ‘Eden Rosso’ had higher ΦDo, ABS/RC, and DIo/RC under 6500 and 3000 K white LEDs, respectively, contradicting the results observed for plant sizes. In addition, PIABS values were higher for P. obtusifolia under 4100 and 6500 K white LEDs and the highest for ‘Eden Rosso’ under 6500 K white LED. In conclusion, P. obtusifolia can be cultivated under 4100-6500 K white LEDs, whereas, ‘Eden Rosso’ and ‘Napoli Nights’, under 6500 and 4100 K white LEDs, respectively.
Plants under the genus Orostachys have been known as medicinal plants. This study deems to determine the growth and leaf color of Orostachys japonica and O. boehmeri when subjected to various LED light sources. A total of seven LED light treatments were used, i.e. red (630 nm), green (520 nm), blue (450 nm), purple (650 and 450 nm), 3000 K white (455, 600 nm), 4100 K white (455, 590 nm), and 6500 K white (450, 545 nm) LEDs. Results showed that O. japonica plants showed favorable growth under 4100 K white LED, while O. boehmeri plants had a positive growth response under white light LEDs (3000, 4100, and 6500 K). In leaf color analysis, the use of green LED showed the greatest change in CIELAB L * and b * values which were relatively higher compared to other treatments indicating that leaves turned yellowish. Further statistical analysis using Pearson’s correlation also suggested that there is a small negative association between dry weight and b * values of O. japonica, and a negative moderate association between plant weights (fresh and dry weight) and leaf color (L * and b * ) and positive association between said plant weights and a * color values of O. boehmeri. Therefore, it is recommended to cultivate O. japonica under 4100 K white LED and O. boehmeri under 3000, 4100, 6500 K white LEDs.
Background and objective: The genus Viola, a member of the Violaceae family, is renowned for its ornamental flower crops. Additionally, Viola species are relatively pest-resistant and easy to manage. They are widely used in gardens, and some of their flowers are even edible. In this study, our focus was on V. cornuta cv. Penny Red Wing (hereinafter referred to as ‘Penny Red Wing’), an experimental plant chosen for its high ornamental value and rapid growth. Methods: We applied a purple light-emitting diode (LED) and three types of white LEDs with varying color temperatures: 3000, 4100, and 6500 K, respectively, as artificial light sources. Notably, purple LED have a far-red wavelength (700-800 nm) ratio of approximately 17.6% in their spectral power distribution. Results: The findings indicated that several parameters exhibited higher values under purple LED: shoot size parameters, shoot biomass, moisture content of shoots and roots, photochemical reflectance index (PRI), modified chlorophyll absorption ratio index (MCARI), total number of flowers, flower size parameters, scent score, Fv/Fm, and PIABS. However, the 6500 K white LED led to higher evaluations of root length, number of shoots and leaves, root biomass, moisture content of shoots and roots, Fv/Fm, and PIABS. Nevertheless, it was observed that shoot growth was relatively hindered, and the flowering responses were inadequate under the 6500 K white LED, suggesting their unsuitability for the mass production of ‘Penny Red Wing’. Furthermore, the 3000 and 4100 K white LEDs were also deemed unsuitable for cultivating ‘Penny Red Wing’ due to their lower cultivation efficiency. Conclusion: ‘Penny Red Wing’ was evaluated as having superior growth, flowering, and chlorophyll fluorescence responses under purple LED, indicating that the far-red wavelength had a more pronounced effect compared to the green wavelength (500-600 nm). Therefore, we recommend cultivating this cultivar under purple LED, which include the far-red wavelength.
Simple Summary
Today, Panax ginseng C. A. Meyer, which has high economic value, is cultivated for the purpose of using the shoot as well as the root, which is better known as the medicinal properties. However, when ginseng is grown outdoors, the quantity and quality of the crop are negatively affected by the climatic environment. In this study, we compared and analyzed the physiological and growth responses of P. ginseng under different LED spectra in a plant factory to achieve continuous and increased productivity. Red and yellow light effectively increased shoot biomass, whereas white light effectively increased root biomass. Furthermore, the intercellular CO2 partial pressure was identified as the most significant physiological variable contributing to root production. Research on light spectra in controlled environments can provide insights into increasing P. ginseng production and contribute to the understanding of the physiological and growth responses of shade-tolerant plants such as P. ginseng.
Abstract
To identify effective light spectra for increasing the productivity of Panax ginseng, we conducted experiments in a controlled environment using a hydroponic cultivation system in a plant factory. We investigated the effect of single LEDs (red, blue, and yellow) and mixed LEDs (red + blue and red + blue + white). The relationships between four light spectra (red, blue, yellow, and white) and physiological responses (net photosynthetic rate, stomata conductance, transpiration rate, and intercellular CO2 partial pressure), as well as growth responses (shoot and root biomass), were analyzed using multivariate statistical analysis. Among the four physiological response variables, shoot biomass was not increased by any pathway, and root biomass was increased only by the intercellular CO2 partial pressure. Red and yellow light increased shoot biomass, whereas white light promoted an increase in the net photosynthetic rate and enhanced root biomass. In contrast, blue light was less effective than the other light spectra in increasing both shoot and root biomass. Therefore, red and yellow light are the most effective light spectra for increasing shoot biomass and white light is effective for increasing root biomass in a plant factory that uses artificial LED lighting. Furthermore, the intercellular CO2 partial pressure is an important physiological variable for increasing the root biomass of P. ginseng.
Pachyphytum, a slow-growing succulent genus, is considered a high-value ornamental plant in high demand as a potted plant. To facilitate and enhance its vegetative propagation, different light-emitting diode (LED) light qualities were used on leaf cuttings. Different light spectrum qualities, i.e., red (peak at 630 nm), blue (peak at 450 nm), purple (peaks at 450 and 650 nm), 3000 K white LED (peaks at 455 and 600 nm), 4100 K white LED (peaks at 455 and 590 nm), and 6500 K white LED (peak s at 450 and 545 nm), were used as treatments for six Pachyphytum species or cultivar, specifically P. compactum, P. glutinicaule, P. machucae, P. oviferum, P. viride, and P. cv. Oviride (P. oviferum × P. viride). The results of this study suggest that the different light qualities studied here significantly affected the growth and development of the Pachyphytum species. The use of blue and 6500 K white LED lights increased survival rates, rooting, and shooting success, while the use of white lights significantly improved shoot and root growth as well as the corresponding fresh and dry weights. However, in terms of the percentage moisture content, the effects of monochromatic red and blue lights, as well as the composite spectral distribution of purple light, were significantly higher compared to the effect of white light. The improvement in root growth and development, and the fresh and dry weights of Pachyphytum species under different light spectra are evidence that the effects of the light quality vary among plant species even when they belong to the same genus. Similarly, the use of different light qualities may be beneficial at certain growth stages for leaf cuttings to promote the optimal development of plant organs. The results of this study provide improved vegetative propagation techniques for Pachyphytum species and other slow-growing succulents propagated through leaf cuttings.
The flexibility of LED technology, in terms of energy efficiency, robustness, compactness, long lifetime, and low heat emission, as well as its applications as a sole source or supplemental lighting system, offers interesting potential, giving the ornamental industry an edge over traditional production practices. Light is a fundamental environmental factor that provides energy for plants through photosynthesis, but it also acts as a signal and coordinates multifaceted plant-growth and development processes. With manipulations of light quality affecting specific plant traits such as flowering, plant architecture, and pigmentation, the focus has been placed on the ability to precisely manage the light growing environment, proving to be an effective tool to produce tailored plants according to market request. Applying lighting technology grants growers several productive advantages, such as planned production (early flowering, continuous production, and predictable yield), improved plant habitus (rooting and height), regulated leaf and flower color, and overall improved quality attributes of commodities. Potential LED benefits to the floriculture industry are not limited to the aesthetic and economic value of the product obtained; LED technology also represents a solid, sustainable option for reducing agrochemical (plant-growth regulators and pesticides) and energy inputs (power energy).
Chrysanthemum (Chrysanthemum morifolium) is among the most popular ornamental plants, propagated mainly through stem cuttings. There is a lack of information regarding the impact of the lighting environment on the successful production of cuttings and underlying mechanisms. The light spectrum affects plant morphology, growth, and photosynthesis. In the present study, chrysanthemum, cv. ‘Katinka’ cuttings, were exposed to five lighting spectra, including monochromatic red (R), blue (B) lights, and multichromatic lights, including a combination of R and B (R:B), a combination of R, B, and far red (R:B:FR) and white (W), for 30 days. B light enhanced areal growth, as indicated by a higher shoot mass ratio, while R light directed the biomass towards the underground parts of the cuttings. Monochromatic R and B lights promoted the emergence of new leaves. In contrast, individual leaf area was largest under multichromatic lights. Exposing the cuttings to R light led to the accumulation of carbohydrates in the leaves. Cuttings exposed to multichromatic lights showed higher chlorophyll content than monochromatic R- and B-exposed cuttings. Conversely, carotenoid and anthocyanin contents were the highest in monochromatic R- and B-exposed plants. B-exposed cuttings showed higher photosynthetic performance, exhibited by the highest performance index on the basis of light absorption, and maximal quantum yield of PSII efficiency. Although R light increased biomass toward roots, B light improved above-ground growth, photosynthetic functionality, and the visual performance of Chrysanthemum cuttings.
The objective of this study was to observe indoor cultivation system with LED lights (white and infrared) to purple lettuce cv. Mimosa in a micro-growing environment for home cultivation. A conventional cultivation with white lamps was used as a Control. The quality of lettuce was evaluated by measuring several parameters, including the number of commercial leaves (intact)/plant, stem diameter, height of the aereal portion, leaf area, absolute growth rate and productivity. Also, individual phenolics contents and photosynthesis parameters were evaluated. The results obtained showed that indoor cultivation growing results around 60% higher number of leaves per plant and 4.75 x more leaf area in comparison to Control treatment (28 days after transplant). In addition, productivity and absolute growth rate of purple lettuce were positively affected by indoor cultivation system (a leaf area difference of 300 g.cm-2 more than the Control). The light
intensity provided by the LED’s resulted in increased biomass and yield, mainly due to the elevated photosynthetic activity of plants. At the same time, individual phenolic compounds like chlorogenic acid, caffeic acid, chicoric acid, luteoline-7-o-glucoronide, quercetin-3-
malonylglucoside, quercetin acetyl hexoside and cyanidine 3-o-malonylglucoside were identified in purple lettuce cv. Mimosa. Therefore, indoor cultivation system is a viable option to provide the consumer a more natural, practical and healthy food.
The present experiment was carried out during August 2022 to November 2022 in Research Field , Department of Horticulture SHUATS, Prayagraj. The experiment was conducted in Factorial Plot Design (FPD) with five media composition i.e (Soil, Perlite, Sand, Cocopeat,) in different proportion viz. M0-Soil,M1- Perlite +Cocopeat+Sand 1:1:1,M2- Perlite +Cocopeat+Sand 1:1:2,M3- Perlite+Cocopeat+Sand 1:2:1,M4- Perlite+Cocopeat+Sand 2:1:1 in plastic pot for outdoor vertical gardening. Total number of plants are 150, there are two factors .Five variety and each varieties have five plants with three replication. Second factor is the different types of plant such as Begonia semperflorens, Crassula ovata, Syngonium podophyllum, Coleus scutellarioide, Iresine herbstii. From the present experimental growth parameter and ornamental morphological characters observed. Among the five ornamentals plants used Coleus scutellarioide and Jade performed better as ornamentals plants used in vertical garden system with growing media and the media composition M4 (Perlite+Cocopeat+Sand 2:1:1) is the best media composition for the plant growth.