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Frontiers in Horticulture ·

Volume 5 - 2026 | https://doi.org/10.3389/fhort.2026.1777170

Development of a solar smart farm model for the production of temperate crops in the tropics: a case study on Panax ginseng

  • Huu Hoang Nguyen1,2,3
  • Hoan Hao Ho2,3
  • Van Man Tran3,4,5
  • Ngo Hoang Phan1,3
  • Quan Phung3,4
  • That Quang Ton3,4
  • Huy Du Nguyen3,4,6
  • Le Quan Tran3,4
  • Chong-Yeal Kim7*corresponding author
  1. 1Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Vietnam
  2. 2Research Center for High-Tech Application in Agriculture, University of Science, Ho Chi Minh City, Vietnam
  3. 3Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam
  4. 4Faculty of Chemistry, University of Science, Ho Chi Minh City, Vietnam
  5. 5Applied Physical Chemistry Laboratory, University of Science, Ho Chi Minh City, Vietnam
  6. 6Central Laboratory of Analysis, University of Science, Ho Chi Minh City, Vietnam
  7. 7New and Renewable Energy Materials Development Center, Jeonbuk National University, Jeonbuk, Republic of Korea
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Abstract

High cooling-energy requirements and operational costs constrain the controlled-environment production of temperate crops in tropical regions. To overcome these limitations, a Solar Smart Farm (SSF) system was developed as an energy-assisted controlled-environment model for Panax ginseng production in tropical climates. The performance of the SSF system was evaluated in terms of renewable energy contribution, cultivation performance, and phytochemical quality. Growth characteristics and commercial ginseng sprout yield were assessed at 4, 6, 8, and 10 weeks after transplanting (WAT). Total saponin content was determined by ultraviolet-visible spectrophotometry, while major ginsenosides in 6-WAT sprouts were quantified using high-performance liquid chromatography. The integrated semi-transparent solar panels addressed approximately 48% to 63% of the high energy demands of SSF systems. The SSF system, covering an area of 25 square meters, is capable of growing up to 13,650 ginseng seedlings per six-week cycle, with a commercial ginseng sprout rate ranging from 71.52% to 88.91%, depending on seedling quality. Peak growth, reaching a 166% increase in fresh weight by 6 weeks after transplanting (WAT), coincided with the highest saponin content. High-performance liquid chromatography analysis of sprouts at 6 WAT confirmed the presence of key ginsenosides (Rb1, Rd, Re) and a notably high concentration of Rg1 (11.61 mg • g−1). The concentrations of these ginsenosides were comparable to, or even surpassed, those documented in the tested 6-year-old ginseng roots. Specifically, the Rd content in the sprout shoots achieved a 17-fold enhancement over that quantified in the mature roots. These findings demonstrate the technical potential of the SSF system as a controlled-environment agriculture model for cultivating high-value temperate crops such as P. ginseng sprouts in thermally challenging tropical environments.

Keywords

1 Introduction

During the Roman Empire (42 BCE – 37 CE), the original greenhouses were built to protect crops from freezing temperatures in winter (Paris and Janick, 2008). These earliest greenhouse models were quickly adopted and evolved into modern greenhouse or smart farm technologies. Smart farm systems are designed to enhance biomass production within completely closed or semi-closed systems, usually by integrating Internet of Things (IoT) technologies. The real-time data on crops and the physical conditions within the growing chambers enable farmers to precisely monitor crop growth and automate cultivation programs while minimizing pest infestations during crop production (Juneidi, 2022; Kayadibi, 2025; Liu et al., 2021; Shamshiri et al., 2018).

In tropical climatic regions, however, the adoption of traditional greenhouse models faces significant challenges. These include excessively high cooling costs due to the greenhouse effect (du Plessis et al., 2015; Shamshiri, 2013), substantial upfront infrastructure investments (Amici et al., 2025; Nwanojuo et al., 2025), and the typically low economic efficiency of leafy vegetable products (Zha et al., 2023). Consequently, the development of better smart farm production systems in tropical areas necessitates experimentation with climate-smart solutions, such as agrophotovoltaics.

The Solar Smart Farm (SSF) system includes smart farm models in combination with solar panels, allowing for agriculture integrated with green energy generation in the same cultivation area. The electricity produced by solar panels is used to operate the smart farm system functions, especially cooling (Wielgat et al., 2024). In tropical regions with very high solar radiation (Polo et al., 2015), SSF systems could have significantly higher energy efficiency. However, the high initial investment cost of SSF systems necessitates suitable cash crops to ensure the sustainability of business models.

Panax ginseng C.A.Meyer, 1842, also known as Korean ginseng, is a suitable crop for testing a climate-independent agricultural cultivation model using the SSF system. Unlike common leafy vegetables, ginseng sprout is a special vegetable with exceptionally high economic and medicinal value (Baik et al., 2021; Cho et al., 2022; Du et al., 2018; Hu et al., 2022; J. Song et al., 2023; M. Wang et al., 2017). The short cultivation time (4-6 weeks) for ginseng sprouts offers a quick return on investment (T. K. Lee et al., 2022). However, the expansion of ginseng cultivation in countries with hot tropical climates faces difficulties due to low physiological temperature requirements (J. W. Lee et al., 2016; Park et al., 1979; Walia et al., 2023).

P. ginseng cultivation has been explored in highland environments that provide naturally cooler temperatures (Walia et al., 2023) and in closed plant factory systems equipped with artificial LED lighting (Anh et al., 2024; Cho et al., 2022; Y. J. Kim et al., 2020; J. Song et al., 2023). While LED-based systems enable precise environmental control, their dependence on artificial lighting substantially increases electricity requirements (Cai et al., 2025). Conversely, greenhouse cultivation under natural sunlight can reduce lighting energy demand but often encounters difficulties in maintaining suitable temperatures for temperate crops in tropical conditions. The SSF system was designed as a hybrid cultivation approach that combines the use of natural solar radiation with environmental control while integrating photovoltaic-based renewable energy generation. However, it remains unclear whether an SSF system can maintain environmental conditions suitable for P. ginseng growth while relying primarily on natural solar radiation under true tropical climatic conditions. Therefore, this study aimed to evaluate the feasibility of cultivating P. ginseng sprouts in an SSF system under tropical environmental conditions.

2 Materials and methods

2.1 Solar smart farm system

The Solar Smart Farm (SSF) system was established at the University of Science – Vietnam National University Ho Chi Minh City, Vietnam, within a tropical zone (10°52’37.1”N, 106°47’56.0”E). The vertical ginseng cultivation unit was fabricated by repurposing a 40-foot intermodal container, yielding overall dimensions of 12.19 m × 3.00 m × 2.90 m (length × width × height). The internal volume was divided into three functional zones: a control room, the main cultivation chamber, and a storage area (Figure 1A). To maximize natural light interception, the original upper surface and the east- and west-facing lateral walls were replaced with tempered glass. The exterior of these three surfaces was integrated with ten semi-transparent photovoltaic (PV) panels per side, resulting in a total installed capacity of 2.6 kW per surface (Figure 1B). These PV panels were designed to partially meet the system’s electrical power demands (Kang et al., 2024, in Korean).

Design of the solar smart farm (SSF) system utilizing standard containers for *P. ginseng* production. **(A)** The SSF system diagram; **(B)** The actual panoramic view of SSF system (12.19 m length × 3.00 m width × 2.90 m height) with solar panels (2.095 m length × 1.039 m width); **(C)** The control room with the control panel; scale bar = 10 cm; Temp, temperature, %RH, relative humidity; **(D)** An integrated digital sensor system inside the growth chamber; scale bar = 5 cm; **(E)** Growth chamber with three rows of seven-tier stacks of truncated cone-shaped plastic pots (25 cm top diameter × 12 cm bottom diameter × 20 cm height); **(F)** The design of *P. ginseng* sprouts cultivation experiment.
Figure 1. Design of the solar smart farm (SSF) system utilizing standard containers for P. ginseng production. (A) The SSF system diagram; (B) The actual panoramic view of SSF system (12.19 m length × 3.00 m width × 2.90 m height) with solar panels (2.095 m length × 1.039 m width); (C) The control room with the control panel; scale bar = 10 cm; Temp, temperature, %RH, relative humidity; (D) An integrated digital sensor system inside the growth chamber; scale bar = 5 cm; (E) Growth chamber with three rows of seven-tier stacks of truncated cone-shaped plastic pots (25 cm top diameter × 12 cm bottom diameter × 20 cm height); (F) The design of P. ginseng sprouts cultivation experiment.

The SSF system is engineered for semi-automated operation, centrally managed from a dedicated control chamber. This chamber integrates the core IoT system equipment, solar inverters (Dong Yang E&P), electrical metering devices, monitoring displays (Samsung) for security cameras (Hikvision), and the control box responsible for managing the cultivation environment (Figure 1C). These integral components support both the direct use of solar power generation and the wireless transmission of operational data to cloud storage. This infrastructure facilitates remote monitoring and control of the entire system via a smartphone application (FarmIn app, Suhwooms Co., Ltd) (Supplementary Figure 1).

Temperature control within the cultivation chamber is maintained at a set point of 18°C using two 5-horsepower inverter air conditioning units (ZPNQ48GT3A0/ZUAD1, LG). Integrated digital sensors (Figure 1D) and an external climate sensor are linked to the IoT system to continuously acquire internal and ambient environmental data. Furthermore, several mechanisms are integrated for microclimate regulation: a drip irrigation system manages water supply, while air circulation and ventilation fans regulate airflow and relative humidity (RH). Specifically, automatic ventilation fans are activated to exhaust saturated air when RH exceeds its 40% set point. A retractable shading net regulates solar radiation input; for this experiment, the insulation set point was established at 0 W·m−2 to maintain the net in a permanently closed state. This configuration minimizes the transmission of solar thermal radiation, thereby reducing the electrical energy load required for active cooling.

This system is specifically engineered for vertical farming applications. The cultivation architecture consists of seven pots sequentially stacked using poly (vinyl chloride) piping, forming vertical poles (Figure 1E). An automated drip irrigation emitter is installed at the apex of each pole. The plastic cultivation pots, measuring 25 cm in upper diameter and 20 cm in height, are designed to accommodate a maximum density of 30 ginseng sprouts each. The complete cultivation system comprises 455 pots, arranged across 5 rows × 13 poles × 7 tiers. This configuration yields a maximum cultivation capacity of 13,650 ginseng sprouts per cycle.

2.2 Environmental parameter monitoring and energy performance assessment

Air temperature, RH, substrate temperature, and carbon dioxide (CO2) concentration were monitored using two integrated digital sensors (Figure 1D). Environmental parameters were recorded manually at three representative daytime intervals because continuous automated monitoring was unavailable during the experimental period. For assessment of spatial variability, light intensity (Mini Lux UYIGAO® UA-962 Digital Light Meter, China) was recorded hourly from 06:00 to 18:00. These measurements were taken across three vertical tiers (top, middle, and bottom, corresponding to the 1st, 4th, and 7th pots) within five representative columns (A02, E02, C07, A12, and E12) (Figure 1F). The photon lux densities were converted to photosynthetic photon flux density (PPFD) (µmol·m−2·s−1) using a factor of 0.0185 valid for sunlight (Pedersen et al., 2016; Thimijan and Heins, 1983) to ensure physiologically relevant light reporting.

In addition to microclimate monitoring, PV electricity generation and system electricity consumption were recorded to evaluate renewable energy contribution during cultivation. Electrical energy was monitored using dedicated metering systems. Data recorded at various time points throughout the year were aggregated to derive mean daily values. Subsequently, the Renewable Energy Contribution Rate (RREC) was calculated using the equation:

RREC=EPVETotal consumed×100%

where EPV represents the total daily electrical energy generated by the PV panels, and ETotal consumed denotes the total electrical energy demand of the SSF system over a 24-hour period.

2.3 Panax ginseng materials

Panax ginseng landrace ‘Jakyungjong’ was sourced from Sammuruji’s farm, Jeollanam-do, Republic of Korea. Three distinct types of ginseng material, representing three different ontogenetic stages, were evaluated: roots with dormancy-treated apical buds, roots with completed emergence and hooked epicotyls, and 4-week-old sprouts pre-cultivated in Korea (exhibiting fully expanded and horizontally unfolded trifoliate leaflets). These material types were coded as “010”, “019”, and “109” according to the Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH) scale (Y.-S. Kim et al., 2021). Subsequently, material with superior adaptability and growth performance under the experimental conditions was selected for further experimentation. These 1-year-old ginseng roots with broken dormancy and 4 weeks after transplanting (WAT) ginseng seedlings were packaged in expandable polystyrene containers, kept cool with gel ice packs, and transported to Vietnam for 3-4 days (under international project number 122063-3). After which, they were immediately utilized for the experiment.

2.4 Cultivation experiment on P. ginseng sprouts and growth indicators measurements

A preliminary cultivation trial was conducted to identify the most suitable planting material for the subsequent SSF cultivation experiment. Three planting materials (“010”, “019”, and “109”) were evaluated under the cultivation conditions of the SSF system. For materials “010” and “019”, five cultivation poles were used, with seven pots per pole. Planting densities were 22 roots per pot for “010” and 15-20 roots per pot for “019”. Due to limited availability, material “109” was cultivated in five pots on a single pole, with 14-18 plants per pot. The number of surviving and dead sprouts was recorded at 6 WAT, and the survival rate was calculated for each cultivation pot. In this preliminary trial, each pot was treated as an experimental unit for survival assessment.

Following the preliminary trial, three cultivation cycles were conducted in the SSF system, including the primary experimental cultivation cycle performed in August 2023 and two subsequent production cycles completed in April and June 2024. Detailed growth and phytochemical analyses were performed using ginseng sprouts from the August 2023 cultivation cycle, which served as the primary experimental batch for intensive characterization (Figure 1E). The cultivation chamber was spatially divided into three experimental zones to account for positional heterogeneity within the SSF system. Each zone contained six vertical cultivation poles assigned to either the local mixture (LM) or Golden Root (GR) substrate treatment (Figure 1F). Zones 1 and 3 each contained four LM poles and two GR poles, whereas Zone 2 contained three LM poles and three GR poles. The Golden Root substrate was supplied by Nongkyung Co., Ltd., Jincheon, Republic of Korea, serving as the control. Both substrate types consisted of a 7:3 (volume/volume) ratio of peat moss to perlite. Before planting, the pots were filled with the respective substrates and thoroughly saturated with water. Subsequently, ginseng roots (approximately 0.5 g·root−1) were uniformly planted at a density of 30 roots per pot and irrigated again post-planting. Throughout the experimental period, no supplemental fertilization was applied.

For growth characterization, plant samples were collected across multiple zones, poles, and cultivation pots at 4, 6, 8, and 10 WAT. At each sampling time, only a subset of plants was destructively harvested from each cultivation pot (1-4 sprouts per pot), while the remaining plants continued growing for subsequent sampling events. During each harvest event, 150 sprouts per substrate treatment (50 sprouts per zone) were measured to capture biological variability within the SSF cultivation system. Upon harvest, the sprouts were carefully removed from the substrate, and the substrate was detached from the roots. The harvested sprouts were then partitioned into two components: the root and the aerial parts (leaves and stems). Subsequently, growth data were recorded, encompassing: the number of compound leaves, the length of leaves (the distance from the tip of the leaf to where it joins the stalk), roots, and stems (using a Mitutoyo digital caliper), the fresh and dry weight of the roots and the aerial parts (measured with a Digi® DS-302 three-decimal place electronic balance), and the chlorophyll content index (CCI) (determined using an Apogee CCM-200 plus meter). Individual plant measurements obtained from the same cultivation pot were averaged prior to statistical analysis, and each pot was treated as the experimental unit.

Commercial sprout production was additionally recorded across three primary cultivation runs to evaluate production continuity of the SSF system under repeated cultivation conditions. Commercial-grade ginseng sprouts were defined as visually healthy sprouts with normal shoots, without severe morphological defects in leaves, root rot symptoms, or loss of marketability at harvest (Supplementary Figure 2). Commercial sprout rate was calculated as the percentage of harvested sprouts meeting commercial-grade criteria relative to the total number of transplanted roots.

The effects of vertical light distribution within the SSF system on the growth performance of P. ginseng sprouts were also evaluated. At 6 WAT, the survival rate and fresh biomass of sprouts were recorded from six cultivation poles distributed throughout the cultivation chamber. Each pot was defined as an experimental unit. For vertical stratification analysis, the upper tier (“Top”) included pots 1-2 from the top of each pole, the middle tier (“Middle”) included pots 3-5, and the lower tier (“Bottom”) included pots 6-7. The survival rate (%) was calculated as the percentage of surviving sprouts relative to the total number of transplanted roots per pot. The average sprout fresh weight (g·plant−1) was calculated by dividing the total fresh biomass harvested per pot by the number of surviving sprouts.

2.5 Extraction and quantitative analysis of saponins and ginsenosides

Roots and aerial parts (leaves and stems) were rinsed with distilled water and oven-dried at 60°C. These parts of ginseng sprouts from each treatment were finely ground, and saponins were extracted via ultrasonic-assisted extraction using the 70% methanol solvent at 50°C. Subsequently, the methanol was evaporated from the extract. The sample was then partitioned with diethyl ether. The diethyl ether layer was removed, and the aqueous layer was extracted with n-butanol. Finally, the n-butanol fraction was evaporated and re-dissolved in methanol.

Total saponin content was estimated using the vanillin-sulfuric acid colorimetric method (Anh et al., 2018). The methanol extracts were reacted with 8% vanillin reagent in 72% sulfuric acid at 60°C for 10 min, followed by cooling in an ice bath. The absorbance of the reaction mixture was measured at 554 nm using a double-beam ultraviolet-visible (UV-Vis) spectrophotometer (Shimadzu, Japan). Ginsenoside Rg1 was used as the reference standard to generate the calibration curve. Results were expressed as % (weight/weight) Rg1 equivalents relative to dry sample weight (DW) and subsequently converted to mg Rg1 equivalents per g DW for graphical presentation using the conversion factor: 1% (weight/weight) = 10 (mg·g−1 DW).

Method validation was evaluated based on the linearity and repeatability of the vanillin–sulfuric acid assay. The calibration curve generated using ginsenoside Rg1 showed excellent linearity within the tested concentration range, with the regression equation y = 0.0208x + 0.0338 and a correlation coefficient (R2) of 0.9997 (Supplementary Figure 3). Method repeatability was assessed by seven replicate analyses of the same sample, yielding a relative standard deviation (%RSD) of 1.7% (Supplementary Table 1), indicating good precision. According to Association of Official Analytical Chemists (AOAC) guidelines, the assay was considered acceptable for the estimation of total saponin content in ginseng samples. Since the vanillin-sulfuric acid reaction is not fully specific to saponins, the assay was used for relative estimation of total saponin content.

Ginsenosides Rg1, Re, Rb1 and Rd were quantified following the AOAC HPLC method described by (Brown et al., 2013). The 6 WAT ginseng sprout extracts (see Section 2.6) were analyzed using a high-performance liquid chromatography (HPLC) system (Agilent 1200 Series, USA) equipped with a diode-array detector (DAD) for the quantification of four major ginsenosides (Rb1, Rd, Re, and Rg1). Separation was performed on an Extend-C18 Zorbax column (250 × 4.6 mm, 5 μm particle size). The mobile phase consisted of solvent A (water) and solvent B (80 acetonitrile: 20 water, volume/volume) under gradient elution conditions (Supplementary Table 2), at a flow rate of 1 mL·min−1. The column temperature was maintained at 25°C, and the injection volume was 20 μL. Detection was performed at 203 nm.

Authentic standards of ginsenosides Re, Rg1 (Sigma-Aldrich), Rb1, and Rd (Vietnam National Institute of Drug Quality Control), were used for peak identification and calibration. Calibration curves in the concentration range of 5-50 μg·mL−1 showed good linearity (R² > 0.996; Supplementary Figure 4). The limit of quantification (LOQ) for Re, Rg1, Rb1, and Rd was 5 μg·mL−1 according to AOAC guidelines.

Each treatment comprised three biological replicates, and each sample was analyzed in triplicate to evaluate repeatability, which was comparable to that reported in the AOAC method. The recovery values of the spiked samples fell within the range reported in the AOAC method (89-112%). The HPLC analysis was conducted concurrently with controls consisting of pre-transplanting ginseng roots (0 WAT) and 6-year-old ginseng roots. Representative chromatograms and calibration curves are provided in the supplementary information.

2.6 Statistical analysis

In this study, data were visualized using graphical representations generated by GraphPad Prism software (version 10.4.1) and analyzed using R statistical software package (version 4.3.3) (R Core Team, 2024). Environmental condition parameters inside the SSF system, light intensity, the sprout’s survival rate, saponins and ginsenosides content were subjected to one-way or two-way analysis of variance (ANOVA) followed by Tukey’s honest significant difference (HSD) post-hoc test, with statistical significance declared at α = 0.05.

Growth parameters were analyzed using linear mixed-effects models, with substrate treatment, cultivation time, and their interaction treated as fixed effects. Cultivation pole and cultivation pot nested within cultivation pole were included as random effects to account for the hierarchical structure of the SSF cultivation system and repeated destructive sampling conducted within the same pots across cultivation periods. Each cultivation pot was considered the experimental unit, and measurements obtained from multiple plants within the same pot were averaged prior to analysis. Type III analysis of variance with Satterthwaite’s approximation was used to evaluate the significance of fixed effects, followed by Tukey’s HSD test for pairwise comparisons of estimated marginal means at α = 0.05. Model assumptions were evaluated through residual diagnostic analyses. Data are presented as mean ± standard error (SE). Different superscript letters indicate statistically significant differences among treatments.

3 Results and discussion

3.1 Microclimate regulation and energy performance of the SSF system

The solar smart farm (SSF) system generated a microclimate suitable for the growth and development of Panax ginseng sprouts. Throughout the experimental period, the highest mean air temperature recorded within the system was 19.39 ± 0.18°C at midday, about 1.71°C higher than in the morning (Table 1). The mean substrate temperature also exhibited minor diurnal fluctuations, increasing during the midday period (from 16.93 ± 0.07°C to 18.74 ± 0.17°C) and slightly decreasing in the afternoon (18.15 ± 0.19°C) (Table 1). The midday increases in air and substrate temperature reflected intense solar radiation, despite continuous environmental regulation within the SSF system.

Table 1. The environmental conditions inside the solar smart farm system.

Time of the dayAir temperature(°C)Substrate temperature(°C)Relative humidity(%)CO2 concentration(ppm)
Morning17.68 ± 0.10b16.93 ± 0.07c75.79 ± 1.25a367.38 ± 6.41a
Noon19.39 ± 0.18a18.74 ± 0.17a66.19 ± 0.59b321.14 ± 4.81c
Afternoon17.67 ± 0.43b18.15 ± 0.19b70.19 ± 1.73b342.12 ± 6.32b

Values are presented as mean ± SE based on measurements collected over 25 days (n = 25 days) by integrated digital sensor systems inside the solar smart farm. Data were collected at three time points each day: morning (6:00-8:00), noon (11:00-12:00) and afternoon (17:00-18:00), from August 14th to September 10th, 2023. Different letters indicate statistically significant differences according to one-way ANOVA followed by Tukey’s post-hoc test (P < 0.05).

Unlike conventional greenhouses in tropical climates, which frequently experience excessive daytime heat accumulation, the SSF system generally maintained air and root-zone temperatures within the reported favorable ranges for ginseng cultivation throughout the experimental period. The temperatures inside the SSF system remained within 16-25°C for air (Walia et al., 2023), and 16-18°C for root-zone substrate (Yeong-yuh, 1974). In sharp contrast, ambient external air temperatures at the installation site averaged 29.4°C in August and 28.2°C in September 2023, with maxima reaching 36.0°C (Southern Regional Hydro-Meteorological Center). The relatively moderated internal temperature of the SSF system under tropical conditions was likely achieved through combined operation of air conditioning, shading nets, and partial solar shading from the semi-transparent PV panels. These findings suggest that the SSF system may help alleviate thermal stress constraints associated with temperate crop cultivation under tropical climatic conditions.

The observed midday increase in air temperature was inversely associated with a decrease in RH. Relative humidity decreased from 75.49% in the morning (from 6:00 to 8:00) to 66.19% at noon (from 11:00 to 12:00) (Table 1). This pattern was likely associated with the inverse physical relationship between air temperature and RH, whereby warmer air has a greater moisture-holding capacity, thereby reducing RH when atmospheric moisture content does not increase proportionally. While the precise optimal air RH for P. ginseng sprouts has not been definitively established in the literature, RH levels ranging from 60% to 70% have frequently been maintained in previous ginseng sprout cultivation studies under controlled-environment conditions (Cho et al., 2022; Y. J. Kim et al., 2020). The relatively stable RH conditions observed in the SSF system may have contributed to reducing excessive transpiration stress during sprout establishment under tropical environmental conditions. Maintaining moderate RH levels may also help reduce the risk of excessive moisture accumulation and associated microbial problems within densely planted vertical cultivation systems.

Throughout the experimental period, the mean CO2 concentration exhibited clear diurnal variation, decreasing from 367.38 parts per million (ppm) in the morning to a minimum of 321.14 ppm at midday (Table 1). These concentrations were consistently lower than the ambient atmospheric CO2 levels of approximately 400 ppm reported in previous ginseng cultivation studies (Jang et al., 2015; Y. J. Kim et al., 2020). The reduced daytime CO2 concentration was likely associated with active CO2 consumption by the dense ginseng sprout canopy within the relatively enclosed SSF cultivation chamber. Ventilation fans were therefore necessary to introduce fresh external air and replenish CO2 within the cultivation chamber. However, under tropical environmental conditions, continuous intake of warm external air may simultaneously increase internal thermal load and cooling demand, thereby creating a potential trade-off between CO2 replenishment and cooling energy demand.

Although the observed sub-ambient CO2 concentrations may have partially limited photosynthetic carbon assimilation within the dense cultivation system, the extent of this limitation could not be directly evaluated because photosynthetic performance was not measured in the present study. A previous controlled-environment study reported that combined changes in environmental factors, including elevated CO2 concentration and temperature, influenced photosynthetic and ecophysiological responses in P. ginseng cultivation systems (K.-M. Lee et al., 2012). Nevertheless, marketable sprout production and biomass accumulation were still achieved under the measured environmental conditions, indicating that the SSF system remained operationally capable of supporting short-cycle ginseng sprout cultivation under tropical conditions. Future studies incorporating direct photosynthetic measurements and controlled CO2 enrichment experiments would be valuable for clarifying the physiological impacts of sub-ambient CO2 conditions and for optimizing ginseng sprout productivity within SSF cultivation systems.

Light distribution within the SSF system exhibited both temporal and vertical heterogeneity. The top tiers (tiers 1-2) generally received higher light intensities than the middle (tiers 3-5) and bottom tiers (tiers 6-7), with differences ranging from approximately 10% to 151% depending on the time of day (Figure 2A). Interestingly, the highest mean light intensities were recorded at 09:00 and 14:00, rather than at solar noon (Figure 2A). This pattern was likely associated with the transparent glass structure of the SSF system combined with the presence of overhead shading nets, while the lateral sides of the structure remained partially exposed to direct sunlight during the morning and afternoon periods. During midday hours (11:00-13:00), solar radiation was distributed more uniformly throughout the cultivation chamber, resulting in more consistent vertical light gradients and statistically significant differences among cultivation tiers (Figure 2A). In contrast, during morning and afternoon periods, localized side illumination generated greater spatial variability in light distribution within individual cultivation zones.

The effect of vertical light stratification on ginseng sprouts yield. **(A)** Daytime light intensity at top, middle, and bottom cultivation layers in the SSF system. Light intensity was measured at five poles, with three measurement positions recorded within a representative pot at each cultivation layer (n = 15). Values are presented as mean ± SE. Horizontal bars indicate pairwise comparisons among the top, middle, and bottom growth zones at the same time point. Asterisks indicate significant differences according to one-way ANOVA followed by Tukey’s post-hoc test (**P < 0.05*, ***P < 0.01*, ****P < 0.001*). **(B)** Survival rate of ginseng sprouts and average sprout fresh weight among the top, middle, and bottom cultivation layers at 6 WAT. Data are presented as mean ± SE (top, n = 12; middle, n = 18; bottom, n = 12). SE, standard error; SSF, solar smart farm; WAT, weeks after transplanting.
Figure 2. The effect of vertical light stratification on ginseng sprouts yield. (A) Daytime light intensity at top, middle, and bottom cultivation layers in the SSF system. Light intensity was measured at five poles, with three measurement positions recorded within a representative pot at each cultivation layer (n = 15). Values are presented as mean ± SE. Horizontal bars indicate pairwise comparisons among the top, middle, and bottom growth zones at the same time point. Asterisks indicate significant differences according to one-way ANOVA followed by Tukey’s post-hoc test (*P < 0.05, **P < 0.01, ***P < 0.001). (B) Survival rate of ginseng sprouts and average sprout fresh weight among the top, middle, and bottom cultivation layers at 6 WAT. Data are presented as mean ± SE (top, n = 12; middle, n = 18; bottom, n = 12). SE, standard error; SSF, solar smart farm; WAT, weeks after transplanting.

Under conventional cultivation conditions in Korea, Panax ginseng is typically grown under relatively low irradiance levels ranging from approximately 50 µmol·m−2·s−1 to 111 µmol·m−2·s−1 (G. S. Kim et al., 2012; B. Lee et al., 2022; Yeong-yuh, 1974). Previous studies have also reported that excessive light exposure (180 µmol·m−2·s−1) can induce photoinhibition symptoms in ginseng, including chlorosis, necrosis, and growth suppression (J. Song et al., 2023). In the present study, most estimated PPFD values within the SSF system remained within the range of approximately 40 µmol·m−2·s−1 to 120 µmol·m−2·s−1 (Figure 2A), which is broadly consistent with the low-light requirements of this shade-adapted species. Despite the observed vertical heterogeneity in light distribution, no significant differences in fresh biomass or survival rate were detected among cultivation tiers (Figure 2B). This result suggests that the light gradients generated within the SSF system were insufficient to substantially affect short-cycle ginseng sprout production. The relatively broad tolerance of ginseng to low-light environments may have contributed to the stable growth performance observed across vertical cultivation positions.

These findings indicate that the SSF system may be particularly suitable for cultivating shade-tolerant crops such as P. ginseng, especially under tropical conditions where excessive solar radiation and heat accumulation can limit crop establishment. In addition to renewable electricity generation, the overhead semi-transparent PV panels likely contributed to moderating incoming solar radiation within the cultivation chamber (S. Kim et al., 2021; Marrou et al., 2013). However, while reduced irradiance may benefit shade-adapted species, the cultivation of photophilous crops within vertically integrated SSF systems may require supplemental LED lighting to compensate for reduced photosynthetically active radiation. Future optimization of PV coverage, shading intensity, and artificial lighting strategies may therefore be necessary to balance energy efficiency with crop-specific light requirements.

In the present study, PPFD values were estimated indirectly from lux measurements using a conversion factor of 0.0185 adapted from previous photometric-to-quantum conversion studies under broad-spectrum sunlight conditions (Thimijan and Heins, 1983). Because the SSF system relied primarily on natural sunlight filtered through semi-transparent PV panels and shading materials, the conversion factor was used to provide an approximate estimation of relative light distribution within the cultivation chamber rather than absolute quantum flux measurements. Although spectral modifications caused by PV glazing and shading nets may introduce some conversion uncertainty, the estimated PPFD values were considered sufficient for comparative evaluation of vertical light heterogeneity within the SSF system. Future studies incorporating direct quantum-sensor measurements would provide a more accurate characterization of spatial and temporal light conditions for system optimization.

Throughout the study period, the integration of semi-transparent solar panels contributed 47.69% to 63.17% of the total electrical energy required by the system (Supplementary Table 3). This performance is consistent with the 33-67% coverage reported by Ghoulem et al. (2019) for similar PV applications (Ghoulem et al., 2019). Previous ginseng sprout cultivation studies conducted in fully enclosed vertical farms and LED-based plant factory systems relied primarily on artificial lighting and mechanical environmental control (Cho et al., 2022; Y. J. Kim et al., 2020; J. Song et al., 2023). In contrast, the SSF system utilized natural solar radiation as the primary light source, thereby potentially reducing electricity demand associated with artificial lighting. However, solar heat gain through the transparent structure simultaneously increased cooling requirements under tropical conditions, indicating a trade-off between lighting energy reduction and thermal regulation demand. A previous study has similarly emphasized that hybrid cooling and environmental control strategies are often necessary to balance crop productivity, energy consumption, and thermal stability under hot-climate cultivation systems (Ghoulem et al., 2019). Although the SSF system was not fully energy autonomous during the present study, the integration of PV energy generation substantially reduced dependence on external electricity sources. Future implementation of continuous automated electricity monitoring, energy storage systems, and optimization of cooling-ventilation strategies may further improve long-term energy efficiency and operational sustainability.

3.2 Adaptation and growth performance of P. ginseng sprouts under SSF environment

Previous research has reported that the primary plumule of P. ginseng is highly susceptible to high-temperature stress (28-30°C) (Hong et al., 2022). This temperature sensitivity may limit the successful establishment of P. ginseng under conventional greenhouse conditions in tropical climates without intensive environmental regulation. In addition, transportation of planting materials to tropical regions may further expose ginseng roots to transient heat stress prior to cultivation.

Three types of planting material representing distinct growth stages (Figure 3A) were used to evaluate the influence of initial root/seedling ontogeny on the adaptation and subsequent growth of P. ginseng within the SSF system under tropical conditions. The results indicated that roots with dormancy-treated apical buds (stage “010”) exhibited the highest survival rate (91.8%), significantly greater than that of the other two material types (Figure 3B). The superior survival performance of stage “010” materials may be associated with their physiologically dormant state prior to active shoot emergence. In perennial ginseng roots, dormancy has been reported to function as an adaptive physiological state regulated by stress-related hormonal networks and environmental responses (Hong et al., 2024; R. Li et al., 2024). Therefore, dormant planting materials may exhibit lower sensitivity to transplanting stress and fluctuating environmental conditions during early establishment compared with actively sprouting or plantlet materials (J. Y. Kim et al., 2016).

The effects of material types on *P. ginseng* development in the solar smart farm system. **(A)** Three types of ginseng materials at three different growth stages 010, 019 and 109 according to BBCH scale; **(B)** Survival rate of ginseng plants at 6 WAT in the SSF system. Data are presented as mean ± SE (n = 35 pots for materials 010 and 019; n = 5 pots for material 109). Asterisks indicate significant differences among material types according to one-way ANOVA followed by Tukey’s post-hoc test (**P < 0.05*, ***P < 0.01*, ****P < 0.001*, *****P < 0.0001*). Scale bar = 3 cm. SE, standard error; WAT, weeks after transplanting.
Figure 3. The effects of material types on P. ginseng development in the solar smart farm system. (A) Three types of ginseng materials at three different growth stages 010, 019 and 109 according to BBCH scale; (B) Survival rate of ginseng plants at 6 WAT in the SSF system. Data are presented as mean ± SE (n = 35 pots for materials 010 and 019; n = 5 pots for material 109). Asterisks indicate significant differences among material types according to one-way ANOVA followed by Tukey’s post-hoc test (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001). Scale bar = 3 cm. SE, standard error; WAT, weeks after transplanting.

Although both substrates consisted mainly of peat moss and perlite, variations in material origin and substrate properties may influence cultivation performance. To evaluate the growth performance of ginseng sprouts cultivated within the SSF system under tropical conditions with locally available substrates, plant growth parameters were recorded at 4, 6, 8, and 10 WAT (Figure 4). The results suggested that the local mixture (LM) substrate supported ginseng sprout growth comparably to the imported Golden Root (GR) substrate. No significant differences in biomass yield were observed between the two substrate treatments, although the chlorophyll index of plants cultivated in the GR substrate was significantly higher than that of plants grown in the LM substrate (Table 2). The comparable growth performance observed in the LM substrate suggests that locally formulated cultivation media may be suitable for short-cycle ginseng sprout production under controlled-environment conditions. The higher chlorophyll index observed in GR-grown plants may reflect differences in nutrient availability or root-zone physicochemical properties between the two substrates.

The growth of ginseng sprouts in the solar smart farm system in Vietnam at 4, 6, 8, and 10 weeks after transplanting (WAT) on two types of substrates: Golden Root (Korea) and local mixture (Vietnam). Scale bar = 3 cm. Pot top diameter: 25 cm.
Figure 4. The growth of ginseng sprouts in the solar smart farm system in Vietnam at 4, 6, 8, and 10 weeks after transplanting (WAT) on two types of substrates: Golden Root (Korea) and local mixture (Vietnam). Scale bar = 3 cm. Pot top diameter: 25 cm.

Table 2. The growth of ginseng sprouts on two types of substrates in the solar smart farm under the tropical climate.

WATSubstrate type# of compound leavesLeaf length (mm)Fresh weight (g)Dry weight (g)Plant height (mm)Chlorophyll content index
Stem-leavesRootStem-leavesRootStemRoot
4Local mixture1.90 ± 0.050a53.49 ± 1.03b0.62 ± 0.032b0.52 ± 0.031d0.10 ± 0.006c0.10 ± 0.011d55.72 ± 2.17a131.40 ± 2.81b7.83 ± 0.138d
Golden root1.91 ± 0.063a51.82 ± 1.29b0.60 ± 0.040b0.50 ± 0.039d0.10 ± 0.008c0.09 ± 0.014d53.29 ± 2.72a126.62 ± 3.52b8.86 ± 0.173ab
6Local mixture1.98 ± 0.050a59.08 ± 1.03a0.73 ± 0.032a0.60 ± 0.031c0.13 ± 0.006b0.16 ± 0.011c56.13 ± 2.17a125.08 ± 2.81b6.82 ± 0.138e
Golden root1.91 ± 0.063a60.37 ± 1.29a0.77 ± 0.040a0.60 ± 0.039c0.15 ± 0.008a0.16 ± 0.014c56.69 ± 2.72a118.24 ± 3.52b8.12 ± 0.173c
8Local mixture1.97 ± 0.050a57.64 ± 1.03a0.76 ± 0.032a0.78 ± 0.031b0.13 ± 0.006ab0.23 ± 0.011b55.01 ± 2.17a131.32 ± 2.81b7.22 ± 0.138e
Golden root1.84 ± 0.063a58.30 ± 1.29a0.71 ± 0.040a0.73 ± 0.039b0.14 ± 0.008a0.21 ± 0.014b53.20 ± 2.72a125.02 ± 3.52b9.14 ± 0.173a
10Local mixture1.92 ± 0.050a59.56 ± 1.03a0.77 ± 0.032a0.98 ± 0.031a0.14 ± 0.006a0.32 ± 0.011a54.73 ± 2.17a140.45 ± 2.81a6.32 ± 0.138f
Golden root1.91 ± 0.063a57.39 ± 1.29a0.73 ± 0.040a1.02 ± 0.039a0.15 ± 0.008a0.31 ± 0.014a55.09 ± 2.72a142.26 ± 3.52a8.54 ± 0.173bc

The experiment investigated the effects of substrate type (Local Mixture vs. Golden Root) and cultivation time (4, 6, 8, and 10 weeks after transplanting) on plant growth. Values represent estimated marginal means ± SE derived from a linear mixed-effects model (n = 126 pot-level observations). Cultivation pole and cultivation pot were included as random effects to account for spatial heterogeneity and repeated destructive subsampling within pots. Different letters indicate statistically significant differences among all substrate × cultivation time combinations according to Tukey’s HSD test (P < 0.05). WAT, weeks after transplanting.

In the present study, leaf biomass peaked at 6 WAT and remained relatively stable until 10 WAT, whereas root weight continued to increase throughout the cultivation period (Table 2). This growth pattern suggests that early vegetative development was prioritized during the initial cultivation stage, followed by continued root biomass accumulation during later growth stages. A similar shift from shoot expansion toward belowground biomass accumulation during later developmental stages has also been reported in a previous ginseng cultivation study under temperate conditions (Chen et al., 2022). Under Korean cultivation conditions, a previous study has reported that ginseng leaves may begin lignification or senescence from approximately 8 WAT onwards (Jang et al., 2018). Therefore, harvesting at 6 WAT may represent a suitable balance between maximizing leaf biomass and maintaining desirable leafy vegetable quality for commercial sprout production.

The ginseng sprout cultivation system evaluated in the present study exhibited nutritional limitations during extended cultivation periods. Nutrient deficiency in P. ginseng has previously been associated with premature leaf senescence (J. Y. Kim et al., 2016). In the present study, visible deficiency-like symptoms began to appear from approximately 10 WAT onwards, including uniform chlorosis and necrotic lesions on the leaves (Supplementary Figure 5A). Similar symptoms have previously been reported in association with deficiencies of nitrogen, potassium, and iron in ginseng cultivation systems (J.-F. Li et al., 2020). In particular, nitrogen limitation has been associated with increased stem and leaf lignification, which may reduce tissue tenderness and market quality in leafy ginseng sprouts (Fritz et al., 2006; Jang et al., 2018; Shao et al., 2020).

The observed nutrient deficiency symptoms were likely associated with the low inherent nutrient content of the peat moss-perlite substrate used in this study, combined with the absence of supplemental fertilization throughout cultivation. Also, no supplemental fertilization was applied throughout the experimental duration. Nevertheless, because commercially harvestable sprouts were successfully produced within 6 WAT, the current cultivation strategy may still be suitable for short-cycle ginseng sprout production as a leafy vegetable system. Future studies investigating advanced nutrient supplementation strategies, including plasma-activated water technologies (J.-S. Song et al., 2021), may help alleviate nutrient limitations and further improve sprout productivity under controlled-environment cultivation systems.

The high-density cultivation within vertically integrated SSF systems may additionally increase susceptibility to disease development under controlled-environment conditions. Several disease-like symptoms were observed during cultivation, including root cracking, basal stem rot, and root rot (Supplementary Figures 5B–D). Similar disease-related challenges have also been highlighted in controlled-environment hydroponic cultivation systems for P. ginseng sprouts, where dense planting arrangements and localized microenvironmental conditions may promote rapid disease spread and crop deterioration (Kim et al., 2023).

Several bacterial strains were isolated from the decaying stem and root tissues; however, none successfully fulfilled Koch’s postulates under the present experimental conditions. Therefore, the causal agents associated with these symptoms remain unresolved. These findings highlight the importance of future investigations into disease etiology, microbial ecology, and integrated disease management strategies to improve the long-term operational stability of SSF-based ginseng sprout cultivation systems.

In addition to the primary experimental cultivation cycle conducted in August 2023, two subsequent cultivation cycles in April and June 2024 were completed. Across the three cultivation cycles, commercial ginseng sprouts were successfully harvested from transplanted roots. The commercial sprout rates were recorded at 88.91%, 76.31%, and 71.52% for the August 2023, April 2024, and June 2024 batches, respectively (Supplementary Table 4). Variations in commercial sprout rate were observed among cultivation cycles, which may be associated with differences in cultivation conditions, transportation stress, and the physiological quality of planting materials between production periods. Such variability is expected in repeated cultivation systems using biologically heterogeneous root materials. However, energy consumption per unit biomass (kWh·kg−1) could not be determined because total fresh biomass production was not systematically recorded across commercial cultivation cycles. In the present production system, commercial performance was evaluated based on the number of marketable ginseng sprouts, reflecting common market practices in which ginseng sprouts are frequently sold individually rather than by fresh weight. Future studies should incorporate systematic fresh biomass measurements to enable quantitative evaluations of energy efficiency per unit biomass produced.

Direct comparisons with previously reported tropical cultivation systems remain limited because P. ginseng is primarily cultivated in temperate regions. Available studies have largely focused on long-term root production in cooler highland environments (Walia et al., 2023) or on artificial-light cultivation systems rather than sprout production under tropical conditions. Therefore, the present study provides one of the first datasets describing the growth and quality characteristics of P. ginseng sprouts cultivated in a solar-assisted controlled-environment system under true tropical conditions.

3.3 Total saponins and ginsenosides accumulation

The phytochemical quality of ginseng sprouts cultivated under tropical condition within the SSF system was evaluated through quantification of total saponins using the vanillin-sulfuric acid UV-Vis spectrophotometric method. The results suggested that LM substrate did not significantly reduce total saponins accumulation compared with the imported GR substrate (Figure 5). This finding indicates that locally available cultivation substrates may be suitable for maintaining the phytochemical quality of short-cycle ginseng sprout production under controlled-environment conditions.

Total saponin content in stem-leaves, roots, and whole plants of ginseng sprouts grown on two substrate types (LM and GR) and harvested at 4, 6, 8, and 10 WAT in the SSF system. Data are presented as mean ± SE (n = 3). Different letters indicate significant differences among substrate × plant-part combinations within the same harvesting time according to one-way ANOVA followed by Tukey’s post-hoc test (*P < 0.05*). GR, Golden Root; LM, local mixture; SE, standard error; WAT, weeks after transplanting.
Figure 5. Total saponin content in stem-leaves, roots, and whole plants of ginseng sprouts grown on two substrate types (LM and GR) and harvested at 4, 6, 8, and 10 WAT in the SSF system. Data are presented as mean ± SE (n = 3). Different letters indicate significant differences among substrate × plant-part combinations within the same harvesting time according to one-way ANOVA followed by Tukey’s post-hoc test (P < 0.05). GR, Golden Root; LM, local mixture; SE, standard error; WAT, weeks after transplanting.

Two-way ANOVA revealed that harvest time significantly affected total saponin content in roots, shoots, and whole plants (Supplementary Table 5). The highest total saponins concentrations in the aerial parts, roots, and whole plants were observed at 6 WAT (Figure 5), coinciding with the stage of peak leaf biomass accumulation. Thereafter, total saponins content gradually decreased at 8 and 10 WAT. Previous studies on ginseng sprouts have also reported temporal variation in ginsenoside accumulation during plant development and across different harvest stages (Jang et al., 2018; Jeong et al., 2018). The elevated saponins content observed at 6 WAT may reflect active secondary metabolism during the early vegetative growth phase, whereas the subsequent decline at later stages may be related to biomass expansion, nutrient redistribution, or age-related physiological changes.

Notably, total saponins concentrations in the aerial tissues at 6 WAT were approximately 2.1-fold higher than those detected in the roots (Figure 5). These results are consistent with previous analyses of ginseng sprouts cultivated in Korea, where leaves and stems were reported to contain substantial concentrations of bioactive ginsenosides relative to underground tissues (Baik et al., 2021; X.-G. Li et al., 2012). The relatively high phytochemical accumulation observed in aerial tissues further supports the potential application of ginseng sprouts as a phytochemically enriched functional crop produced within short cultivation cycles. However, the vanillin-sulfuric acid assay provides an estimation of total saponin-like compounds and may also respond to other triterpenoid constituents. Therefore, the UV-Vis-derived total saponin values should be interpreted as approximate estimates rather than absolute ginsenoside concentrations.

The phytochemical composition of 6 WAT ginseng sprouts cultivated within the SSF system under tropical conditions was further characterized using HPLC analysis. Major ginsenosides, including Rb1, Rd, Re, and Rg1, were successfully detected in both aerial and root parts (Supplementary Figure 6), indicating that major pharmacologically relevant ginsenosides could still accumulate under tropical controlled-environment cultivation conditions. Distinct tissue-specific patterns of ginsenoside accumulation were observed. Ginsenoside Rb1 accumulated predominantly in the roots, where its concentration exceeded that of the aerial parts by more than 35.3-fold (Table 3). In contrast, the aerial parts contained substantially higher concentrations of Rd, Re, and Rg1 than the roots (Table 3). Similar tissue-dependent distribution patterns have previously been reported in ginseng sprouts cultivated under Korean conditions (G. O. Lee et al., 2023), suggesting that differential allocation of ginsenosides between underground and aerial organs may represent a conserved physiological characteristic of ginseng sprout development.

Table 3. Comparison of selected ginsenoside contents in pre-transplanting seedlings (0 WAT), 6 WAT sprouts cultivated in the SSF system, and 6-year-old ginseng roots.

SampleGinsenosides content (mg·g−1 dry sample weight)
Rb1RdReRg1
6-years-old root4.38 ± 0.03a0.30 ± 0.01c3.22 ± 0.02b3.98 ± 0.03bc
0 WAT root2.69 ± 0.01b0.57 ± 0.01c1.06 ± 0.02c5.74 ± 0.08b
6 WATRoot4.59 ± 0.06a1.43 ± 0.02b1.50 ± 0.03c4.02 ± 0.20c
Stem-leaves0.13 ± 0.01c5.08 ± 0.06a5.14 ± 0.17a11.61 ± 0.42a

Values are presented as the mean ± SE of triplicate determinations (n = 3). Values within a column with different superscript letters represent statistically significant differences at P < 0.05 by Tukey’s range test. SSF, solar smart farm; WAT, week after transplanting.

The preferential accumulation of certain ginsenosides in aerial tissues may be associated with the high metabolic activity of young leaves and stems during early vegetative growth. Variations in the relative abundance of individual ginsenosides may additionally reflect differences in cultivar characteristics, substrate properties, microenvironmental conditions, and cultivation management practices. Nevertheless, the overall phytochemical profile observed in the present study remained broadly comparable to previously reported profiles of Korean-grown ginseng sprouts, supporting the feasibility of producing phytochemically valuable P. ginseng sprouts within tropical SSF cultivation systems.

In the present study, 6-year-old ginseng roots were additionally analyzed as a reference material to contextualize the phytochemical characteristics of ginseng sprouts cultivated within the SSF system under tropical conditions. Despite a substantially shorter cultivation period, 6 WAT ginseng sprout roots contained Rb1 concentrations comparable to those detected in the tested 6-year-old ginseng roots (Table 3). In addition, the aerial parts of the ginseng sprouts exhibited higher concentrations of Rd, Re, and Rg1 per unit dry mass than those measured in the mature root samples, exceeding them by approximately 17.0-, 1.6-, and 2.9-fold, respectively (Table 3).

Previous studies have demonstrated that these major ginsenosides possess diverse pharmacological activities, including anti-inflammatory, antioxidant, hepatoprotective, neuroprotective, mitigation of stroke-induced damage, and cardiovascular protective effects (Chen et al., 2019; D. H. Kim et al., 2013; Peng et al., 2012; Ye et al., 2011; Zhao et al., 2014). The relatively high accumulation of selected ginsenosides in the aerial tissues of ginseng sprouts suggests that young sprouts may serve as a valuable source of bioactive compounds for functional food or medicinal plant applications. However, because the analyzed sprout and mature root materials differed substantially in tissue type, developmental stage, cultivation history, storage condition, and physiological status, these comparisons primarily provide contextual phytochemical reference rather than direct evidence of superior medicinal quality. Therefore, the present findings mainly highlight the capacity of SSF-grown ginseng sprouts to accumulate selected pharmacologically relevant ginsenosides under tropical controlled-environment cultivation, rather than indicating superior medicinal quality relative to mature ginseng roots.

3.4 Study limitations and future perspectives

The present study demonstrates the technical feasibility of cultivating Panax ginseng sprouts under tropical environmental conditions using a solar smart farm (SSF) system. However, several limitations should be acknowledged. Direct comparative cultivation trials with conventional greenhouse systems, non-PV controlled-environment systems, or fully artificial LED-based plant factories were not included in the present study. The limited availability of comparable tropical controlled-environment studies on P. ginseng sprouts also restricts direct benchmarking of SSF performance against alternative cultivation platforms. Therefore, the relative performance of the SSF platform compared with alternative cultivation systems in terms of energy efficiency, environmental stability, and crop productivity requires further validation through direct comparative studies.

In addition, environmental and PV performance data were obtained from representative operational periods rather than from continuous long-term monitoring, which may not fully capture seasonal variability and the full energy balance dynamics. Detailed growth and phytochemical analyses were also conducted primarily during the first cultivation cycle. Furthermore, sequential sampling from the same cultivation pots across different harvest periods may have introduced minor changes in plant density and the local cultivation microenvironment over time. For statistical analysis, cultivation pot means were used as the experimental units to minimize pseudoreplication. However, residual spatial heterogeneity within the vertical cultivation system may still have influenced some measured variables despite the inclusion of cultivation pole and pot effects in the statistical models. Future studies should incorporate automated environmental sensing, continuous electricity monitoring, and direct comparisons with alternative cultivation systems. Additional multi-cycle validation under different seasonal conditions and hierarchical repeated-measures experimental designs would further support the optimization and validation of SSF-based tropical ginseng sprout production systems.

4 Conclusion

As a case study, the present work demonstrated the technical feasibility of cultivating Panax ginseng sprouts under tropical environmental conditions using a semi-transparent solar smart farm (SSF) system. The integration of semi-transparent photovoltaic panels and IoT functions enabled a semi-automated and climate-smart production environment that contributed to moderating the excessive thermal load commonly associated with conventional greenhouse structures. Concurrently, the SSF system facilitated dual outputs-renewable electricity generation and medicinal plant biomass production at a commercially relevant scale. From a broader perspective, this study highlights the SSF system as a promising platform technology for sustainable agriculture in tropical regions. The system may also offer a conceptual framework for future controlled-environment crop production in extreme environments, including potential extraterrestrial habitats, although this possibility requires substantial further investigation.

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Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fhort.2026.1777170/full#supplementary-material

Supplementary material Supplementary material at the source

Footnotes

Edited by: Saeid Hazrati, Azarbaijan Shahid Madani University, Iran

Reviewed by: Encai Bao, Northwest A&F University

Xiaofan Yang, Beijing Normal University, China

Footnotes

ANOVA, analysis of variance; AOAC, Association of Official Analytical Chemists; BBCH, Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie; BCE, before Common Era; CCI, chlorophyll content index; CE, Common Era; CO2, carbon dioxide; DAD, diode-array detector; DW, dry weight; GR, Golden Root; HPLC, high-performance liquid chromatography; IoT, internet of things; LED, light-emitting diode; LM, local mixture; LOQ, limit of quantification; PPFD, photosynthetic photon flux density; ppm, parts per million; PV, photovoltaic; RH, relative humidity; RSD, relative standard deviation; SE, standard error; SSF, solar smart farm; UV-Vis, ultraviolet-visible; WAT, weeks after transplanting.

Statements

Conflict of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Funding

The author(s) declared that financial support was received for this work and/or its publication. This paper was supported by research funds of Jeonbuk National University in 2025. This work was carried out with the support of 'Cooperative Research Program for Agriculture Science and Technology Development (Project No. RS-2025-02183070)' Rural Development Administration, Republic of Korea.

Data availability

The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: Harvard Dataverse, https://doi.org/10.7910/DVN/W3RTYB.

Author contributions

HN: Conceptualization, Data curation, Formal analysis, Methodology, Supervision, Visualization, Writing – original draft, Writing – review & editing. HH: Conceptualization, Investigation, Methodology, Visualization, Writing – original draft, Writing – review & editing. VT: Conceptualization, Funding acquisition, Methodology, Writing – review & editing. NP: Methodology, Writing – review & editing. QP: Methodology, Writing – review & editing. TQT: Methodology, Writing – review & editing. HN: Methodology, Writing – review & editing. LT: Methodology, Supervision, Validation, Writing – review & editing. C-YK: Funding acquisition, Investigation, Project administration, Resources, Writing – review & editing.

Acknowledgements

We thank Trung Chanh Tran, Gia Tuong Tran and Thu Ha Nguyen (Research Center for High-tech Application in Agriculture, University of Science – Vietnam National University Ho Chi Minh City) for their help in conducting experiments and statistically analyzing data. We also thank Mr. Lim Seon-Ho (Sammuruji, Jeollanam 57232, Republic of Korea) for providing ginseng materials and advising on ginseng cultivation.

References

  1. Amici A. S., Appicciutoli D., Bentivoglio D., Staffolani G., Chiaraluce G., Mogetta M.. (2025). From seed to profit: a comparative economic study of two Italian vertical farms. Front. Sustain. Food Syst. 9. doi: doi:10.3389/fsufs.2025.1584778
  2. Anh H. L. T., Duc N. V., Cong P. V., Hieu N. V., Dan N. V., Trang V. T.. (2024). Chemical constituents of Panax ginseng sprouts cultivated in Vietnam. Vietnam J. Chem. 62, 165 – 171. doi: doi:10.1002/vjch.202300181
  3. Anh L. V., Sophie P. E., Minh N. H., Paul R. D. (2018). Improving the vanillin-sulphuric acid method for quantifying total saponins. Technologies 6, 84. doi: doi:10.3390/technologies6030084
  4. Baik I. H., Kim K. H., Lee K. A. (2021). Antioxidant, anti‐inflammatory and antithrombotic effects of ginsenoside compound k enriched extract derived from ginseng sprouts. Molecules 26, 4102. doi: doi:10.3390/molecules26134102
  5. Brown P. N., Yu R., Cain T., Huie G., Jin C. D., Kababick J. N.. (2013). Determination of ginsenoside content in Panax ginseng C.A. Meyer and Panax quinquefolius L. root materials and finished products by high-performance liquid chromatography with ultraviolet absorbance detection: interlaboratory study. J. AOAC Int. 96, 12 – 19. doi: doi:10.5740/jaoacint.12-153
  6. Cai W., Bu K., Zha L., Zhang J., Lai D., Bao H. (2025). Energy consumption of plant factory with artificial light: challenges and opportunities. Renewable Sustain. Energy Rev. 210, 115235. doi: doi:10.1016/j.rser.2024.115235
  7. Chen J., Zhang X., Liu X., Zhang C., Shang W., Xue J.. (2019). Ginsenoside Rg1 promotes cerebral angiogenesis via the PI3K/Akt/mTOR signaling pathway in ischemic mice. Eur. J. Pharmacol. 856, 172418. doi: doi:10.1016/j.ejphar.2019.172418
  8. Chen T., Wang L., Wang H., Jiang S., Zhou S. (2022). Photoperiod and temperature as dominant environmental drivers triggering plant phenological development of American ginseng along with its quality formation. Front. Earth Sci. 10. doi: doi:10.3389/feart.2022.894251
  9. Cho K. M., Lee H. Y., Cho D. Y., Jung J. G., Kim M. J., Jeong J. B.. (2022). Comprehensive comparison of chemical composition and antioxidant activity of Panax ginseng sprouts by different cultivation systems in a plant factory. Plants 11, 1818. doi: doi:10.3390/plants11141818
  10. du Plessis E., Workneh T., Laing M. (2015). “ Greenhouse cooling systems and models for arid climate,” in Sustainable Agriculture Reviews, vol. 18. Ed. Lichtfouse E. (Springer, Cham, Switzerland), 181 – 215. doi: doi:10.1007/978-3-319-21629-4_6
  11. Du Y., Fu M., Wang Y. T., Dong Z. (2018). Neuroprotective effects of ginsenoside Rf on amyloid-β-induced neurotoxicity in vitro and in vivo. J. Alzheimer’s Dis. 64, 309 – 322. doi: doi:10.3233/JAD-180251
  12. Fritz C., Palacios-Rojas N., Feil R., Stitt M. (2006). Regulation of secondary metabolism by the carbon-nitrogen status in tobacco: nitrate inhibits large sectors of phenylpropanoid metabolism. Plant J. 46, 533 – 548. doi: doi:10.1111/j.1365-313X.2006.02715.x
  13. Ghoulem M., El Moueddeb K., Nehdi E., Boukhanouf R., Kaiser Calautit J. (2019). Greenhouse design and cooling technologies for sustainable food cultivation in hot climates: review of current practice and future status. Biosyst. Eng 183, 121 – 150. doi: doi:10.1016/j.biosystemseng.2019.04.016
  14. Hong J., Geem K. R., Kim J., Jo I. H., Yang T. J., Shim D.. (2022). Prolonged exposure to high temperature inhibits shoot primary and root secondary growth in Panax ginseng. Int. J. Mol. Sci. 23, 11647. doi: doi:10.3390/ijms231911647
  15. Hong J., Han S., Geem K. R., Bae W., Kim J., Jee M.-G.. (2024). Identification of a key signaling network regulating perennating bud dormancy in Panax ginseng. J. Ginseng Res. 48, 511 – 519. doi: doi:10.1016/j.jgr.2024.04.004
  16. Hu J., Zhang L., Fu F., Lai Q., Zhang L., Liu T.. (2022). Cardioprotective effect of ginsenoside Rb1 via regulating metabolomics profiling and AMP-activated protein kinase-dependent mitophagy. J. Ginseng Res. 46, 255 – 265. doi: doi:10.1016/j.jgr.2021.06.011
  17. Jang I. B., Lee D. Y., Yu J., Park H. W., Mo H. S., Park K. C.. (2015). Photosynthesis rates, growth, and ginsenoside contents of 2-yr-old Panax ginseng grown at different light transmission rates in a greenhouse. J. Ginseng Res. 39, 345 – 353. doi: doi:10.1016/j.jgr.2015.03.007
  18. Jang I. B., Yu J., Suh S. J., Jang I. B., Kwon K. B. (2018). Growth and ginsenoside content in different parts of ginseng sprouts depending on harvest time. Korean J. Medicinal Crop Sci. 26, 205 – 213. doi: doi:10.7783/KJMCS.2018.26.3.205
  19. Jeong D. H., Lee D. Y., Jang I. B., Yu J., Park K. C., Lee E. H.. (2018). Growth and ginsenoside content of one year old ginseng seedlings in hydroponic culture over a range of days after transplanting. Korean J. Medicinal Crop Sci. 26, 464 – 470. doi: doi:10.7783/KJMCS.2018.26.6.464
  20. Juneidi S. J. (2022). Smart greenhouses using internet of things: case study on tomatoes. Int. J. Smart Sens. Intelligent Syst. 15, 1 – 15. doi: doi:10.2478/ijssis-2022-0019
  21. Kang S.-H., Choi J.-H., Jung I.-S., Lim G.-Y., Park J.-W., Hoang N. H.. (2024). Development of light distributed solar modules for growing sprout ginseng and overseas empirical research on natural lighting cultivation system. Curr. Photovoltaic Res. 12, 24 – 30. Available online at: https://journal.kpvs.or.kr/articles/article/82W1/ (Accessed July 3, 2026).
  22. Kayadibi İ. (2025). An IoT-driven framework based on sensor technology for smart greenhouses and precision agriculture. Int. J. Smart Sens. Intelligent Syst. 18, 1 – 13. doi: doi:10.2478/ijssis-2025-0005
  23. Kim T. H., Baek S., Kwon K. H., Oh S. E. (2023). Hierarchical machine learning-based growth prediction model of Panax ginseng sprouts in a hydroponic environment. Plants 12, 3867. doi: doi:10.3390/plants12223867
  24. Kim D. H., Chung J. H., Yoon J. S., Ha Y. M., Bae S., Lee E. K.. (2013). Ginsenoside Rd inhibits the expressions of iNOS and COX-2 by suppressing NF-κB in LPS-stimulated RAW264.7 cells and mouse liver. J. Ginseng Res. 37, 54 – 63. doi: doi:10.5142/jgr.2013.37.54
  25. Kim J. Y., Kim D. H., Kim Y. C., Kim K. H., Han J. Y., Choi Y. E. (2016). In vitro grown thickened taproots, a new type of soil transplanting source in Panax ginseng. J. Ginseng Res. 40, 409 – 414. doi: doi:10.1016/j.jgr.2016.05.003
  26. Kim S., Kim S., Yoon C. Y. (2021). An efficient structure of an agrophotovoltaic system in a temperate climate region. Agronomy 11, 1584. doi: doi:10.3390/agronomy11081584
  27. Kim G. S., Lee S. E., Noh H. J., Kwon H., Lee S. W., Kim S. Y.. (2012). Effects of natural bioactive products on the growth and ginsenoside contents of Panax ginseng cultured in an aeroponic system. J. Ginseng Res. 36, 430 – 441. doi: doi:10.5142/jgr.2012.36.4.430
  28. Kim Y. J., Nguyen T. K. L., Oh M. M. (2020). Growth and ginsenosides content of ginseng sprouts according to led-based light quality changes. Agronomy 10, 1979. doi: doi:10.3390/agronomy10121979
  29. Kim Y.-S., Park C.-S., Lee D.-Y., Lee J.-S., Lee S.-H., In J.-G.. (2021). Phenological growth stages of Korean ginseng (Panax ginseng) according to the extended BBCH scale. J. Ginseng Res. 45, 527 – 534. doi: doi:10.1016/j.jgr.2020.12.006
  30. Lee G. O., Jang S. N., Kim M. J., Cho D. Y., Cho K. M., Lee J. H.. (2023). Comparison of growth patterns and metabolite composition of different ginseng cultivars (Yunpoong and K-1) grown in a vertical farm. Horticulturae 9 (5), 583. doi: doi:10.3390/horticulturae9050583
  31. Lee J. W., Kim Y. C., Kim J. U., Jo I. H., Kim K. H., Kim D. H. (2016). Effects of gibberellic acid and alternating temperature on breaking seed dormancy of Panax ginseng C. A. Meyer. Korean J. Medicinal Crop Sci. 24, 284 – 293. doi: doi:10.7783/KJMCS.2016.24.4.284
  32. Lee K.-M., Kim H.-R., Lim H., You Y.-H. (2012). Effect of elevated CO 2 concentration and temperature on the growth and ecophysiological responses of ginseng (Panax ginseng C. A. Meyer). Korean J. Crop Sci. 57, 106 – 112. doi: doi:10.7740/kjcs.2012.57.2.106
  33. Lee T. K., Lee J. Y., Cho Y.-J., Kim J.-E., Kim S. Y., Yoon Park J. H.. (2022). Optimization of the extraction process of high levels of chlorogenic acid and ginsenosides from short-term hydroponic-cultured ginseng and evaluation of the extract for the prevention of atopic dermatitis. J. Ginseng Res. 46, 367 – 375. doi: doi:10.1016/j.jgr.2021.10.006
  34. Lee B., Pham M. D., Cui M., Lee H., Hwang H., Jang I.. (2022). Growth and physiological responses of Panax ginseng seedlings as affected by light intensity and photoperiod. Hortic. Environ. Biotechnol. 63, 835 – 846. doi: doi:10.1007/s13580-022-00448-0
  35. Li R., Li Y., Tang M., Qu Z., Shao C., Zheng P.. (2024). Transcriptomic and metabolomic research on the germination process of Panax ginseng overwintering buds. Plants 13, 1041. doi: doi:10.3390/plants13071041
  36. Li J.-F., Shao H.-H., Bi Y.-M., Jiao X.-L., Zhang X.-M., Gao W.-W. (2020). Effects of nutrients deficiency on growth and saponin accumulation of American ginseng. China J. Chin. Materia Med. 45, 1866 – 1872. doi: doi:10.19540/j.cnki.cjcmm.20200205.111
  37. Li X.-G., Yan Y. Z., Jin X.-J., Kim Y. K., Uddin R., Kim Y. B.. (2012). Ginsenoside content in the leaves and roots of Panax ginseng at different ages. Life. Sci. J. 9, 679 – 683.
  38. Liu Y., Mousavi S., Pang Z., Ni Z., Karlsson M., Gong S. (2021). Plant factory: a new playground of industrial communication and computing. Sensors 22, 147. doi: doi:10.3390/s22010147
  39. Marrou H., Wery J., Dufour L., Dupraz C. (2013). Productivity and radiation use efficiency of lettuces grown in the partial shade of photovoltaic panels. Eur. J. Agron. 44, 54 – 66. doi: doi:10.1016/j.eja.2012.08.003
  40. Nwanojuo M. A., Anumudu C. K., Onyeaka H. (2025). Impact of controlled environment agriculture (CEA) in Nigeria, a review of the future of farming in Africa. Agriculture 15, 117. doi: doi:10.3390/agriculture15020117
  41. Paris H. S., Janick J. (2008). “ What the Roman emperor Tiberius grew in his greenhouses,” in Cucurbitaceae 2008: Proceedings of the Ixth EUCARPIA Meeting on Genetics and Breeding of Cucurbitaceae. Ed. Pitrat M. (Avignon, France: Institut National de la Recherche Agronomique), 33 – 41.
  42. Park H., Kim K.-S., Bae H.-W. (1979). Effect of gibberellin and kinetin on bud dormancy breaking and growth of Korean ginseng root (Panax ginseng C.A. MEY.). J. Ginseng Res. 3, 105 – 112.
  43. Pedersen O., Colmer T. D., Borum J., Zavala‐Perez A., Kendrick G. A. (2016). Heat stress of two tropical seagrass species during low tides – impact on underwater net photosynthesis, dark respiration and diel in situ internal aeration. New Phytol. 210, 1207 – 1218. doi: doi:10.1111/nph.13900
  44. Peng L., Sun S., Xie L., Wicks S. M., Xie J. (2012). Ginsenoside Re: pharmacological effects on cardiovascular system. Cardiovasc. Ther. 30, e183 – e188. doi: doi:10.1111/j.1755-5922.2011.00271.x
  45. Polo J., Bernardos A., Navarro A. A., Fernandez-Peruchena C. M., Ramírez L., Guisado M. V.. (2015). Solar resources and power potential mapping in Vietnam using satellite-derived and GIS-based information. Energy Convers Manage. 98, 348 – 358. doi: doi:10.1016/j.enconman.2015.04.016
  46. R Core Team (2024). R: a Language and Environment for Statistical Computing (Vienna, Austria: R Foundation for Statistical Computing). Available online at: https://www.r-project.org/ (Accessed April 19, 2024).
  47. Shamshiri R. (2013). A review of greenhouse climate control and automation systems in tropical regions. J. Agric. Sci. Appl. 2, 175 – 182. doi: doi:10.14511/jasa.2013.020307
  48. Shamshiri R. R., Kalantari F., Ting K. C., Thorp K., Hameed I. A., Weltzien C.. (2018). Advances in greenhouse automation and controlled environment agriculture: a transition to plant factories and urban agriculture. Int. J. Agric. Biol. Eng 11, 1 – 22. doi: doi:10.25165/j.ijabe.20181101.3210
  49. Shao C. H., Qiu C. F., Qian Y. F., Liu G. R. (2020). Nitrate deficiency decreased photosynthesis and oxidation-reduction processes, but increased cellular transport, lignin biosynthesis and flavonoid metabolism revealed by RNA-Seq in Oryza sativa leaves. PloS One 15, e0235975. doi: doi:10.1371/journal.pone.0235975
  50. Song J.-S., Jung S., Jee S., Yoon J. W., Byeon Y. S., Park S.. (2021). Growth and bioactive phytochemicals of Panax ginseng sprouts grown in an aeroponic system using plasma-treated water as the nitrogen source. Sci. Rep. 11, 2924. doi: doi:10.1038/s41598-021-82487-8
  51. Song J., Yang J., Jeong B. R. (2023). Growth and photosynthetic responses to increased led light intensity in Korean ginseng (Panax ginseng C.A. Meyer) sprouts. Agronomy 13, 2375. doi: doi:10.3390/agronomy13092375
  52. Thimijan R. W., Heins R. D. (1983). Photometric, radiometric, and quantum light units of measure: a review of procedures for interconversion. HortScience 18, 818 – 822. doi: doi:10.21273/HORTSCI.18.6.818
  53. Walia S., Kumar P., Kumar D., Kumar R. (2023). A preliminary study on suitability of growing ginseng (Panax ginseng Meyer) in the Western Himalayan region. Plant Soil Environ. 69, 71 – 80. doi: doi:10.17221/288/2022-PSE
  54. Wang M., Yan S. J., Zhang H. T., Li N., Liu T., Zhang Y. L.. (2017). Ginsenoside Rh2 enhances the antitumor immunological response of a melanoma mice model. Oncol. Lett. 13, 681 – 685. doi: doi:10.3892/ol.2016.5490
  55. Wielgat R., Kolodziej A., Candela L., Lisowska-Lis A., Jasielski J., Chlastawa Ł.. (2024). A concept of smart agro-photovoltaic tunnels. IEEE Access 12, 40765 – 40794. doi: doi:10.1109/ACCESS.2024.3376411
  56. Ye R., Kong X., Yang Q., Zhang Y., Han J., Li P.. (2011). Ginsenoside Rd in experimental stroke: superior neuroprotective efficacy with a wide therapeutic window. Neurotherapeutics 8, 515 – 525. doi: doi:10.1007/s13311-011-0051-3
  57. Yeong-yuh Y. (1974). “ The effects of different shading of mulching on yield of root and quality in Panax ginseng,” in Proceedings of the Ginseng Society Conference (Seoul, South Korea: The Korean Society of Ginseng), 137 – 146.
  58. Zha L., Wang Z., Huang C., Duan Y., Tian Y., Wang H.. (2023). Comparative analysis of leaf vegetable productivity, quality, and profitability among different cultivation modes: A case study. Agronomy 14, 76. doi: doi:10.3390/agronomy14010076
  59. Zhao B.-S., Liu Y., Gao X.-Y., Zhai H.-Q., Guo J.-Y., Wang X.-Y. (2014). Effects of ginsenoside Rg1 on the expression of Toll-like receptor 3, 4 and their signalling transduction factors in the NG108-15 murine neuroglial cell line. Molecules 19, 16925 – 16936. doi: doi:10.3390/molecules191016925

Citation

Nguyen, H. H., et al. (2026). Development of a solar smart farm model for the production of temperate crops in the tropics: a case study on Panax ginseng. Frontiers in Horticulture, Volume 5. https://doi.org/
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5 - 2026

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Copyright © 2026 Nguyen, Ho, Tran, Phan, Phung, Ton, Nguyen, Tran and Kim.

License: https://creativecommons.org/licenses/by/4.0/

*Correspondence: Chong-Yeal Kim

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