1 Introduction

In addition to being a source of food, the swamp cabbage (Ipomoea aquatica) was traditionally used for medicinal purposes. Swamp cabbage or Kangkong, a member of the Convolvulaceae family, generally grows in wet soils and is an aquatic plant. In particular, the evidence suggests that the extracts of leaves and stem showed antidiabetic, anti-inflammatory and antioxidant activities. Swamp cabbage (Ipomoea aquatica), known as Water Spinach or Kang Kong, is a rapidly growing semi-aquatic vegetable in Asia and tropical climates. Swamp cabbage is used as food due to the various nutritional properties it has, including the presence of iron, food fibers, vitamins A, B and C. helps to maintain intestinal health, as well as preventing anemia and increasing immunity (Shah et al., 2023). Swamp cabbage helps to protect ecosystems of wetlands by absorbing excess nutrients from water, which improves its quality. Therefore, the cabbage of the swamp is a potential functional food (Ahmed et al., 2022). Due to climate change and population growth, the swamp cabbage has been taken as a solution for sustainable agricultural growth.

The nutrient circulation of the system's system minimizes water waste and environmental influences and supports sustainable goals of food production (Jensen, 1997; Resh, 2020). Global challenges such as food shortages, land deterioration and water shortages have accelerated the introduction of sustainable cultivation methods such as hydroponics, which enables plants without a soil with optimized nutrient levy (Sousa et al., 2024). Under the hydroponic techniques, nutrient film technology (NFT) for its efficient nutrient and water consumption, a higher root oxygen supply and the compact design for urban and small agriculture (Puerta et al., 2007; Baiyin et al., 2021). NFT systems facilitate continuous nutrient supply and enable the adjustment of nutrient concentrations in real time, which are tailored to specific growth stages, which improves growth, the yield and quality of leaf vegetables such as swamp cabbage (Ahmed et al., 2022; Shah et al., 2023).

The versatility of NFT systems, including temperature regulation and scalability, deals with seasonal stress and improves production efficiency, decisively for the variable climate Bangladesh (Payumi et al., 2022; Das et al., 2022). In addition, the NFT cultivation reduces work in connection with soil preparation and weeds and offers an inexpensive and sustainable alternative to the traditional floor base (Kumar et al., 2023).

In Bangladesh, swamp cabbage is promising due to its adaptability in agrocological zones and fast growth cycle for improving nutritional security and nutrition. Traditional swamp coal cultivation is based on swampy countries, but hydroponic NFT systems can change production by enabling year-round growth in rural and urban environments in the middle of the challenges of land deterioration and climate variaability (Reddy et al., 2022; Ahmed et al., 2023).

This study evaluated three swamp cabbage (Ipomoea aquatica) cultivars—BARI Swamp Cabbage-1, La Procesa Swamp Cabbage-1, and Nice Green—under a Nutrient Film Technique (NFT) hydroponic system during the pre-monsoon and summer seasons in a net-house environment. Growth characteristics, yield components, and key quality traits were systematically assessed to compare cultivar performance under NFT conditions. The primary objective was to identify high-yielding and high-quality swamp cabbage cultivars suitable for NFT hydroponic production, thereby providing a scientific basis for cultivar selection and promoting sustainable and efficient hydroponic cultivation in Bangladesh and similar agro-ecological regions.

2 Materials and Methods

The experiment was took place at the Hajee Mohammad Danesh Science and Technology University's net house in Dinajpur, in the department of horticulture. The experiment aims to give the required information under a number of subheadings pertaining to the instruments and supplies utilized in the current study as well as the procedures employed.

2.1 Experimental site and conditions

The experiment was conducted in the net house and laboratory of the Department of Horticulture, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur, Bangladesh. The study was carried out during the pre-monsoon and summer seasons, with plant growth and yield evaluation conducted from May to July 2023, while biochemical analyses were performed from August to October 2023. The experimental site is geographically located at 25°39′ N latitude and 88°04′ E longitude, at an elevation of 37.5 m above sea level.

During the experimental period, the average maximum air temperature ranged from 32.24 °C to 34.86 °C, while the average minimum temperature varied between 26.61 °C and 28.28 °C, accompanied by high relative humidity (91.43%-92.05%). These climatic conditions are considered suitable for swamp cabbage (Ipomoea aquatica) growth. Monthly average temperature and relative humidity data were obtained from the Climate and Weather Department of the Bangladesh Wheat and Maize Research Institute, Noshipur, Dinajpur, to ensure accurate environmental characterization of the study period.

2.2 Experimental materials

Three swamp cabbage (Ipomoea aquatica) cultivars were used as experimental materials: BARI Swamp Cabbage-1 (V1), La Procesa Swamp Cabbage-1 (V2), and Nice Green (V3) (Figure 1). These cultivars were selected based on their commercial importance, yield potential, and adaptability to soilless cultivation. Seeds were procured from the local market of Dinajpur and were sown after ensuring uniformity and viability.

This experiment analyzed the morphological and biochemical characteristics of three swamp cabbage cultivars in a nutrient-film technique (NFT) system in a net house: (1) BARI Swamp Cabbage-1 (V1) is a high-yielding cultivar with rapid growth and long, thin-leaf green leaves; (2) LP-1 (V2) is a vigorous cultivar, known to have uniform, deep-green foliage and excellent adaptability to a wide range of environmental conditions; and (3) Nice Green Swamp cabbage (V3).

These cultivars are largely known to be very productive and capable of adapting to soilless cultivation, making them applicable in the year-round production. The aim of the current research was to evaluate the possibility of these cultivars in terms of maximizing yield and quality in controlled environmental conditions. The local market in Dinajpur procured the seeds of the three varieties in the local market.

2.3 NFT hydroponic system and experimental layout

The experimental set up was achieved through the use of the nutrient film technique (NFT) hydroponic system in a net house (Figure 2). It included cultivation channels, nutrient reservoir, and a circulation unit provided with submersible pumps that were turned on at the same time. The channels were constantly fed with nutrient solution to ensure that sufficient amounts of nutrients and aeration to the plant roots were provided and thus maintained a productive photo-synthetic activity. The trial design was based on a triple replication, perfectly randomized design (CRD). Each replication was to be carried out by growing all three cultivars under the same environmental conditions and management procedure.

The type of design used was a totally randomized design (CRD) which was a formal experimental set-up. But actually the experiment was carried out on three replications of every cultivar and they all were grown under the same environmental and management conditions and no extreme variations were added.

2.4 Nutrient solution preparation and management

The nutritional needs of the plants were satisfied using the modified Murashige and Skoog (MS) nutrient formulation (Murashige and Skoog, 1962). The nutrient solution was first centred down into two separate stock solutions (Solution 2 and Solution 3) to prevent precipitation of calcium and phosphate salts. Table 1 gives the detailed composition of these stock solutions.

To prepare the working solution, Solution A (500,300 mL) and Solution B (125,300 mL) were mixed in 25,000 mL of water in a 30,000 mL reservoir. The resulting nutrient solution was pumped continuously in the Nutrient Film Technique (NFT) system until the cultivation period ended.

Solution A was made with the dissolution of 114.12 g of nutrients in 2,500 mL of distilled water and Solution B was made by dissolving 0.605 g of nutrients in 500 mL of distilled water. Table 1 shows the chemical composition of each constituent and its concentrations in both stock solutions in details. Solution A contained mainly nitrogen, calcium, potassium and iron, and Solution B contained phosphorus, magnesium, potassium and essential micronutrients needed to grow the plant.

To prepare the final working nutrient solution, 500 mL of Solution A and 125 mL of Solution B were mixed with 25,000 mL of water in a 30,000 mL nutrient reservoir. Throughout the cultivation period, the nutrient solution was in circulation inside the nutrient film technique (NFT) system. The nutrient solution was observed and corrected periodically to maintain its status in terms of electrical conductivity (EC) and pH to provide the best environment to grow swamp cabbage.

2.5 Monitoring of pH, EC, and TDS

Digital meters were used to measure the ph, electrical conductivity (EC) and total dissolved solids (TDS) of the nutrient solution periodically. The pH level was kept at 6.0-7.0 and is the ideal range of swamp cabbage growth; slight pH increments were corrected with the addition of vinegar. The EC was maintained at 0.8-1.0 MS/cm in the early stage of growth and at 1.2-1.8 MS/cm in the later stages, as recommended in the standard hydroponics. Whenever EC was much higher than the desired level, water was diluted and when EC was much lower than desired, nutrient solution was added.

TS is a metric that is used to identify the quality of solutions by determining the quantity of mineral dissolved in water. A TDS meter (model D272, Henan Wanbang EP TECH Co., Ltd., Liangyuan, China) is normally employed to identify the total dissolved solids of a solution, which is usually water.

TDS may be estimated based on EC observations as dissolved ionic solids like salts and minerals increase the conductivity of a solution. In Swamp-Kohl, the highest EC range was held at 0.8-1.0 MS/cm in the initial 10-15 days and 1.2-1.8 MS/cm in the rest of the growth period (Teodor et al., 2021). In case EC values were high, water was added to reduce EC values, and in situations where EC values were low, more nutrient solution was added to increase the conductivity. Swamp cabbage has seasonal changes in PH and electrical conductivity.

2.6 Seed germination, Seedling emergence, transplanting, and crop management

The germination of seeds was done in blocks of sponges soaked in water and placed in plastic trays and then covered overnight to maintain moisture (Figure 3). The seedlings emerged in a window of two days, and the germination rate was approximately 97 per cent (Figure 4) for all cultivars. The germination was followed by the addition of a dilute nutrient solution that would help to promote early plant growth.

On 26 May 2023 the healthy and evenly grown ten-day-old seedlings were relocated to the Nutrient Film Technique (NFT) system. Regular intercultural intervention was done to maintain uniformity in growth by routine gap filling, system sanitation and plant monitoring.

2.7 Algae, pest, and nutrient management

The proliferation of algae was curbed by preventing the light penetration of nutrient reservoirs and pipelines by covering with black polyethylene sheeting, and systematic sanitisation in tandem with the nutrient replacement process. Small amounts of hydrogen peroxide were put in place to retard the growth of algae. There were no cases of pest or pathogenic infestation that were reported during the trial and this could be credited to the introduction of a soilless hydroponic system of cultivation. Initially, a replacement of nutrient solutions was done on a ten day basis but this was later changed to a five day basis to ensure that it was more adjusted to physiological rates of uptake of nutrients by plants (Figure 5).

2.8 Harvesting and data collection

Data were collected at various Days After Transplanting (DAT) on the following morphological, yield contributing, and quality criteria.

2.8.1 Morphological parameters

Plant height, measured using a scale from each plant at 7-day intervals starting at 10 DAT and continuing until 56 DAT, was defined as the distance between the tips of the tallest leaves from the ground. The units were stated in centimeters.

The swamp cabbage plant's overall height was measured at two growth intervals in order to determine the absolute growth rate, or AGR. The daily growth rate was calculated by dividing the difference in plant height by the number of days between the two measurements. The following formula was used to determine the absolute growth rate:

Where, H₁ means height for D1, H₂ means height for D2

Starting at 10 days after transplanting (DAT) and continuing at seven-day intervals, the number of leaves on each plant was recorded until 56 DAT. At the last stage of harvest, the number of branches on each plant was noted. Every primary branch that emerged from the main stem was manually counted, and the average number of plants in the sample was calculated.

The leaf surface was estimated using an index counter in a portable digital leaf zone (YMJ-B, China). The process is to activate the digital lai counter by feeding it and preparing for use. The Zone Index Compt (LAI) is a specialized tool to quantify the surface of the leaves per unit of surface on the ground. A fresh sheet is chosen for the measurement and transmitted through the device sensor. The sensor, specially designed for this purpose, measures the foliar surface (MM2). Leaf length (length of the leaf between the apex and the base of the leaf-stalk) of each plant was recorded at 14-day time intervals starting at 14 days after transplanting (DAT) with a Leaf Area Index Meter, until 42 DAT.

Using the same Leaf area Index Meter, the leaf length to breadth ratio was measured from each plant at 7-day intervals beginning 14 days after transplanting (DAT) and continuing until 42 DAT. At the last stage of harvest, the swamp cabbage plants were carefully uprooted in order to measure the length of their roots. A measuring scale was used to determine the distance between the root collar and the tip of the longest root. Next, the sampled plants’ average root length was determined.

2.8.2 Yield and yield contributing parameter

At each harvest, the plant yield per plant was expressed in grams. The final yield per plant was calculated by adding these figures from each harvest. The final yield per plant was multiplied by the planting density to obtain the total marketable plant yield per hectare. The leaves were then sun-dried for three weeks, followed by another drying in an electric oven at 70 °C for three days. The percentage of the dry mass was calculated using the following formula:

In order to determine the percentage of the dry matter, the fresh weight of the swamp cabbage system was first recorded. As soon as a constant weight was reached, the dry weight was measured using an electronic balance (G G T100, Germany).

2.8.3 Quality parameters

The space was recorded at 14 that 28 and 42. A spad-502 plus (Horiba, Japan) model of a renowned manufacturer was used to measure the chlorophyll content in plant leaves. In the method, clean leaves were picked, the spad-502 plus calibrated, the sensor (2 × 3 mm) were placed on the leaves and spades.

The mix was made by the filter paper from Whatman no. Chlorophyll "A" in leaves was determined using the method of Nagata and Yamashita (1992). 1 filtered and the absorption at 445 Nm and 663 Nm measured. Chlorophyll "A" stop was calculated using the formula. A gram macerated sheet was mixed with 10 mL acetone hexan mixture (4: 6) and swirled for 5 minutes:

Chlorophyll-a (mg/100 g fw) = 0.999A663-0.0989A645

Where, A663 and A645 are the absorbances at 663 nm and 645 nm, respectively.

The same procedure used to measure chlorophyll "a" was used to measure chlorophyll "b" in leaves. The following formula was used to determine the amount of chlorophyll "b":

Chlorophyll-b (mg/100 g fw) = -0.328A663+1.77A645

The amount of beta-carotene in leaves was measured using the technique outlined by Tsiakaras et al. (2014). Ten milliliters of an acetone-hexane (4:6) combination were combined with one gram of macerated leaf, and the mixture was vortexed for five minutes. After passing the combination through Whatman No. 1 filter paper, absorbance measurements were made at 445, 663, 505, and 453 nm. The following formula was used to determine the beta-carotene content:

β-carotene (mg/100 g fw) = 0.216A663-1.22A645-0.304A505+0.452A453

Five grams of leaf tissue were homogenized in 100 mL of oxalic-eda acid solution. The homogenerate was centrifuged at 1,500 rpm for 15 minutes and the Sirnaant was filtered through Whatman n. 1. The ecorbic acid content was determined using the spectrophotometric procedure described by Farajzadeh and Nagizadeh (2003). Absorbance was measured at 760 nm and the concentration of ascorbic acid was quantified using a standard curve of l-ascorbic acid. A 5 mL rate has been mixed with metaphosphoric acid, sulfuric acid and ammonium molybdaded reagents.

2.9 Statistical analysis

The Statistix 10 statistical tool was used to statistically examine the data gathered for various parameters, and analysis of variance was carried out for each recorded parameter. At the 5% level of probability, the Least Significant Difference (LSD) value was used to quantify the importance of the variation in means.

3 Results and Analysis

The results obtained from the experiment are presented and analyzed in this section based on data collected at different days after transplanting (DAT). Growth, yield, and quality parameters of three swamp cabbage (Ipomoea aquatica) cultivars grown under the NFT hydroponic system were statistically analyzed, and significant differences among cultivars were identified. The results are organized into thematic subsections to highlight growth dynamics, morphological traits, yield components, dry matter accumulation, and quality attributes, with tables and figures used to summarize the key findings.

3.1 Morphological parameters

According to these results, V1 has a genetic advantage in the growth of height, which qualifies it as a cultivar for the production of ideal biomass of the NFT system. Significant variations have been observed in the height of the plants between the Cape Cape Cultivars to various DAT, with the exception of 35 and 42 DAT (Table 2). Over time, the height of all cultivars has gradually increased with V1 (Bari Swamp Cabbage-1) which continually produces the highest plants compared to V2 (LP-1) and V3 (Bel Green). The heights of the system varied from 30.33 cm to 27.43 cm per 56 DAT, with V1 that continues to be the highest, followed by V3 and V2 in that order.

The differences observed in the height of the plants between the cultivars can be attributed to their genetic variations. A significant trait that affects the surrender is the height of the plant. In any case, V1 (Bari Swamp Cabbage-1) produced the highest plant, followed by V3 (Bel Green) and V2 (LP-1). Due to the innate cultivation model of the plant, it has been observed that the height of the plant has increased over time. Even environmental factors such as the availability of nutrients, the efficiency of the absorption of water and the adaptability to growth conditions can play a role, but the intrinsic varietal characteristics remain a primary determining factor. The higher performance of V1 suggest greater genetic potential for the extension of the stem and vegetative growth, probably due to the highest cell division rates and internal lengthening (2020), this shows that V1 has a higher development potential. It could be due to the varietal traits of the plant. In line with the previous results of Rahman et al. (2020).

3.2 Absolute growth rate (AGR) per plant

V1 had the highest AGR at 56 DAT (0.62 cm/day), which was much higher than V3S (0.43 cm/day), but not much of V2 (0.59 cm/day). In general, V1 (Bari Swamp Cabbage-1) had a larger AGR than V2 (LP-1) and V3 (beautiful green swamp cabbage). The higher AGR in V1 in early growth stages indicates strong vegetative growth, which could lead to better accumulation of biomass. The absolute growth rate varied significantly throughout the DAT, which indicates the different growth habits of the varieties (Table 3).

The AGR results show that V1 has a notable early growth advantage that might be utilized to maximize production plans by using staggered planting methods or early harvests (Tsiakaras et al., 2014).

3.3 Number of leaves per plant

The number of leaves per plant varied significantly among swamp cabbage cultivars at various DATs (Table 4). All cultivars showed a rise in leaf yield over time, however V1 (BARI swamp cabbage-1) produced the most leaves over all DAT compared to V2 (LP-1) and V3 (Nice Green). Compared to V2 (6.67) and V3 (8.33), V1 exhibited the highest leaf number (8.66) at 7 DAT. At 56 DAT, V1 had 32.33 leaves, V2 had 25.33, and V3 (31.00) was right behind V1. Its genetic potential for high photosynthetic efficiency which is necessary for ideal development and yield is highlighted by V1's enhanced leaf output.

The amount of leaves per plant varied significantly as a result of variability at different DAT. V1 consistently produced more leaves than other cultivars, which may have been due to its genetic potential. According to Haque et al. (2022), this implies that V1 is an excellent choice for maximizing foliage, which is essential for overall production.

3.4 Number of branch per plant

At 14, 28, 35 and 42 days after the transplant (DAT), a significant difference in the number of branches per plant was observed in the swamps (Table 5). With 8.33 branches up to 42 DAT, V1 was again in the lead, followed by V3 (7.33) and V2, which very few (5.33) had. V1 developed most branches (3.00) at 14 DAT and exceeded V2 (2.00), while V3 (2.33) entered the middle. Over time, the industry production with V1 (Bari Swamp Cabbage-1) continuously rose, which produce V2 (LP-1) and V3 (beautiful green). V1’s ability to produce more branches reflects its strong growth habits and the potential for higher biomass and earnings. At 21 DAT, however, no such difference was found.

Branching ability is a significant factor in determining the overall yield potential. V1's higher branching contributed to its superior performance. Because of its improved branching, which facilitates better light interception and nutrient usage, V1 is a good choice for high-yielding systems (Karim et al., 2018).

3.5 Leaf area

With every DAT, remarkable variations in the leaf area were found in the case of swamp cabbage. V1 exceeded V2 (222.33 mm²) and V3 (263.95 mm²) by recording the largest leaf area (647.81 mm²) at 14 DAT (Table 6). The largest leaf area was regularly observed by V1 (Bari Swamp Cabbage-1) compared to V3 (beautiful green) and V2 (LP-1). This pattern was still available at 42 DAT, whereby V1 is still better (664.80 mm²), while V2 and V3 had noticeably reduced the leaf surfaces. The consistently larger leaf surface in V1 reflects its genetic advantage for efficient photosynthesis and contributes to higher growth and earnings potential.

Leaf area is one of the most crucial variables affecting photosynthetic capability and output potential. The larger leaf area of V1 demonstrates its suitability for intensive cropping systems (Ahmed et al., 2022).

The leaf breadth of the various swamp cabbage cultivars varied noticeably at each DAT (Table 7). V1 (BARI swamp cabbage-1), V2 (LP-1), and V3 (Nice Green swamp cabbage) consistently produced the widest leaves. At 14 DAT (33.26 mm), V1's leaves were the broadest and notably larger than those of V2 (23.88 mm) and V3 (23.79 mm). This pattern continued at 42 DAT, with V1 still holding a dominant position (33.89 mm). Wider leaves in V1 suggest the possibility of improved photosynthetic efficiency and light interception, both of which are essential for plant development and yield.

Larger leaves on V1 may increase its ability to absorb sunlight, resulting in improved yield and growth (Khan et al., 2020).

3.6 Leaf length

Significant differences in leaf length were observed between the swamp cabbage cultivars at each day after transplantation (DAT) (Appendix VIII) (Table 8). Compared to V2 (LP-1) and V3 (Nice green swamp cabbage), the leaves of V1 (BARI swamp cabbage-1) were consistently longer. At 14 DAT, V1's leaves were the longest (19.48 mm), significantly longer than those of V2 (9.30 mm) and V3 (11.12 mm). This pattern persisted at 42 DAT, with V2 consistently having the shortest leaves and V1 maintaining its advantage (19.61 mm). V1's longer leaves demonstrate its genetic superiority in creating larger foliage, which promotes improved photosynthetic efficiency and increased yield potential.

Its vigor and productivity may be supported by the longer leaves in V1, which could suggest a genetic advantage in environmental adaptation (Haque et al., 2021).

3.7 Length-to-breadth (L/W) ratio

The length-to-breadth (L/W) ratios of swamp cabbage cultivars showed considerable variation from 14 to 42 DAT, but not at 28 DAT (Appendix IX). In contrast to V2 (LP-1) and V3 (0.47), V1 (BARI swamp cabbage-1) consistently exhibited the highest L/W ratio at 14 DAT (Table 9). V1 kept its advantage (0.58) at 42 DAT, indicating that it could be able to more effectively absorb light and use resources, which would result in improved growth and production.

V1's genetic aptitude for effective resource utilization is highlighted by its increased length-to-breadth ratio (Rahman et al., 2020).

3.8 Root length

V2 showed intermediate roots, starting at 2.97 cm at 7 DAT and growth to 16.03 cm by 56 DAT. This shows its strong genetic advantage in the development of a robust root system. The V1 variety showed the longest roots, starting at 3.77 cm at 7 DAT and reached 20.80 cm times 56 DAT (Table 10). In the varieties, significant differences in the root length were observed, with V1 consistently exceeding the others in all growth phases. The table shows the progression of the root length of different swamps on different days after the transplant (DAT) and their corresponding regular length in different DAT. In contrast, V3 had the shortest roots in all stages, from 3.27 cm at 7 DAT to 14.77 cm to 56 DAT, which indicates a relatively limited capacity for the root extension.

The root length plays a crucial role in determining plant power, nutrient absorption and overall productivity. V1 shows its suitability for maximizing growth and for determining under different soil and environmental conditions, which emphasized the importance of strong root systems for increasing agricultural productivity and resilience. These results match Haque et al. (2021) V1 consistently exceeded other varieties in the root length and emphasized its ability to access distant nutrient resources, which supports its growth under challenging conditions. The moderate root development of V2 indicates the adaptability of less demanding environments, while the shorter roots of V3 can restrict the efficiency of nutrient and water absorption, especially in resource-related environments.

3.9 Dry weight percentage of root

This indicates that despite the variations of the accumulation of dry matter, was relatively consistent. Despite the slight deviations, the percentage of dry weight in the tested varieties was relatively even. The percentage of dry weight at 56 DAT was between 8.36% (V2) and 8.92% (V3), observed without significant differences between the varieties (as NS). The consistency between varieties (known as NS) indicates similar physiological mechanisms that influence the accumulation of the dry matter.

3.10 Yield contributing characteristics

Variety V1 recorded the highest fresh weight (235.03 g), followed by V3 (219.53 g) and V2 (170.27 g). These differences are statistically significant, as stated by the LSD value of 13.13. In the types of swamps, significant differences in the fresh plant weight were observed after 56 days after the transplant (DAT) (Table 11). The superior performance of V1 could be attributed to its genetic features and adaptability to the experimental conditions.

The LSD value of 1.93 confirms the statistical significance of these differences. V1 and V3 provided the highest yields (34.83 or 32.93 tons/ha), exaggerated V2 (25.54 tons/ha). The yield per hectare also showed a significant differences between the swamps. V1 and V3 showed the highest yields and were in voting with their superior fresh weight per plant. These results reflect the trends that are observed in fresh plant weight. The variation of the yield per hectare (25.54-34.83 tons/ha) reflects the genetic potential and adaptability of the swamp cabbage types under the given conditions. The superior yield of V1 underlines the potential for high productivity in the context of the NFT system.

The consistency between varieties (known as NS) indicates similar physiological mechanisms that influence the accumulation of the dry matter. Despite the slight deviations, the percentage of dry weight in the tested varieties was relatively even. V1 had the highest dry weight percentage (12.33%), followed by V2 (11.93%) and V3 (11.54%). The percentage of dry weight showed a closer range (11.54%-12.33%) without significant differences between the varieties. Such trends in relation to yield and dry weight vote with the findings of Kowalczyk et al. (2014), which emphasized the influence of genetic characteristics and environmental factors on the productivity of the plants and the composition of the biomass In contrast to fresh weight and yield, dry weight percentage showed no significant differences between the swamps.

3.11 Quality parameters

The observed fluctuation indicates that the photosynthetic capacity of V2 is relatively unstable over time. Specifically, V2 (LP-1) exhibited the lowest SPAD values, increasing from 28.27 at 14 DAT to 34.20 at 28 DAT, followed by a decline to 29.70 at 42 DAT (Table 12). Significant differences in SPAD values were recorded among the cultivars at all growth stages (14, 28, and 42 DAT).

In contrast, V1 (BARI Swamp Cabbage-1) consistently showed the highest SPAD readings throughout the experimental period, with values of 32.87, 36.90, and 34.90 at 14, 28, and 42 DAT, respectively (Table 12), indicating superior and stable chlorophyll content. V3 (Nice Green) exhibited intermediate SPAD values (29.00, 31.13, and 31.60 at 14, 28, and 42 DAT, respectively), reflecting relatively stable photosynthetic performance across growth stages, although lower than that of V1.

3.12 Content of chlorophyll-a

In every growth phase, there were remarkable variations in the amount of chlorophyll-A in the swamps (14, 28, 42 and 56 DAT). V2 V2 (LP-1) had the maximum chlorophyll a concentration at 14 DAT (0.61 mg/100 g), but its values drastically decreased during the day and reached 0.52 mg/100 g at 56 DAT. The second best performer in this parameter was V3 (nice green), which showed steady intermediate values and its chlorophyll a concentration to 0.60 mg/100 g at 56 DAT (Table 13) at 56 DAT (0.75 mg/100 g) had V1 Bari Swamp Cabbage-1 the highest chlorophyll a level, which is on the larger photosynthetic Efficiency (Appendix XIII) indicates.

These findings suggest that V1 may be better suited for long-term cultivation due to its ability to maintain higher chlorophyll-a levels over time. Since chlorophyll-a directly contributes to the light reaction, it is essential for photosynthesis. V1’S enhanced photosynthetic efficiency and biomass production potential are indicated by its increased chlorophyll-a content. The steady performance of V1 is consistent with research by Ahmed et al. (2021), which emphasized how genetic variables influence chlorophyll content.

3.13 Content of chlorophyll-b

V2 exceeded V1 and V3 with the largest chlorophyll B concentration at 42 DAT (0.19 mg/100 g) .With the values of 0.17 to 0.21 mg/100 g, the variety differences at 56 DAT were no longer significant (Table 14). The amount of chlorophyll-B varied between the varieties, but the changes were not as large as the chlorophyll-A. V2 continuously showed more chlorophyll-B levels in earlier stadiums, which indicates that it could withstand more low levels in early growth.

Chlorophyll-b is an auxiliary pigment that increases the spectrum of light absorption. V2's higher chlorophyll-b content at 42 DAT suggests that it may be tolerant of low light conditions. This trend may be supported by the findings of Khan et al. (2020), who emphasized the role of chlorophyll-b in light gathering and plant resilience.

3.14 Content of β-carotene

At every stage but 42 DAT, there were notable variations in the cultivars' β-carotene concentration .The greatest β-carotene content (0.22 mg/100 g) was reported by V2 at 14 DAT, however, this advantage was lost by 56 DAT, when V1 and V3 overtook it with values of 0.24 mg/100 g and 0.23 mg/100 g, respectively. While V1 showed a dramatic increase at 56 DAT, which indicates its potential for an increased nutritional value when the harvest subsequently, V3 contributed comparatively constant levels in the growth stages (Table 15).

A precursor to vitamin A, β-carotene is essential to human health. Their improved performance at 56 DAT shows the potential of V1 and V3 as nutrient-rich cultivars. Our results are consistent with those of Rahman et al. (2019), who emphasized the genetic basis for β-carotene accumulation in green vegetables. V3 is a strong choice for systems that prioritize stable nutritional quality over extended growth periods, as seen by its consistent performance.

3.15 Ascorbic acid content

With 14 DAT (1.77 mg/100 g), V1 Bari Swamp Cabbage-1 had the highest ascorbic acid content, while V3 (beautiful green) had the best ascorbic acid retention at 56 DAT (1.92 mg/100 g). On all days after the transplant (DAT) there were remarkable differences in the ascorbic acid level between swamp cabbage varieties (Table 16). These results suggest that V3 can be a better choice for the production of nutrient-rich plants, especially for the ascorbic acid content. V3 was better than other varieties at 56 DAT and demonstrated its ability to capture himself over time. The ascorbic acid content of V2 (LP-1) was greatest at 28 DAT (1.98 mg/100 g), followed by V3 (2.00 mg/100 g).

This factor is important to find out the health advantages of the harvest. The potential of V3 for nutritional applications is highlighted by the reported variations of the ascorbic acid level between varieties. V3 and other varieties can be particularly useful in markets in which nutritional quality and yield are given the same weight (Ahmed et al., 2022).

4 Discussion

The present study demonstrated clear varietal differences in growth, yield, and quality traits of swamp cabbage cultivated under a Nutrient Film Technique (NFT) hydroponic system, highlighting the strong influence of cultivar selection on hydroponic performance. The superior growth and yield performance of BARI Swamp Cabbage-1 (V1) suggests that this cultivar possesses higher adaptability to NFT conditions, likely due to its efficient nutrient uptake, vigorous vegetative growth, and effective utilization of water and dissolved nutrients. Similar cultivar-dependent responses under hydroponic systems have been reported in leafy vegetables, where genotypic variation significantly influences growth dynamics and biomass accumulation.

The consistently higher plant height, leaf area, and fresh weight observed in V1 may be attributed to its enhanced photosynthetic capacity and rapid canopy development, which allow more efficient light interception under protected cultivation. NFT systems provide continuous nutrient availability and oxygenated root zones, which favor cultivars with high metabolic activity and rapid nutrient absorption. Previous studies on hydroponically grown leafy vegetables have reported that cultivars with larger leaf areas and faster growth rates tend to produce higher yields due to increased photosynthate production and translocation.

Although Nice Green (V3) produced a slightly lower yield than V1, it exhibited superior quality attributes, including higher vitamin C, chlorophyll-a, and β-carotene contents. These findings suggest that V3 prioritizes biochemical and nutritional compound accumulation rather than maximum biomass production. Enhanced chlorophyll content indicates efficient photosynthetic pigment synthesis, while increased β-carotene and vitamin C levels reflect improved antioxidant capacity. Similar trade-offs between yield and nutritional quality have been reported in hydroponically grown leafy greens, where certain cultivars exhibit enhanced phytonutrient concentration under controlled nutrient and environmental conditions.

The relatively lower and fluctuating performance of La Procesa Swamp Cabbage-1 (V2) indicates moderate adaptability to NFT hydroponic cultivation. Variability in SPAD values and yield suggests less stable chlorophyll synthesis and photosynthetic efficiency over time. This may be due to cultivar-specific differences in nutrient absorption efficiency or root system architecture, which are critical factors in NFT systems where nutrient delivery is continuous but shallow.

Overall, the effectiveness of the NFT system observed in this study supports its potential for year-round swamp cabbage production with efficient water and nutrient use. NFT hydroponics minimizes soil-related constraints, reduces water consumption, and allows precise nutrient management, making it particularly suitable for regions with limited arable land, poor soil fertility, or urban and peri-urban environments. The present findings are consistent with earlier reports that hydroponic systems enhance yield stability and quality of leafy vegetables when appropriate cultivars are selected.

Authors’ contributions

Afrin Fardous designed and conducted the experiment. Md. Sifat Ullah analyzed the DAT and prepared the manuscript. Shreef Mahmood provided technical guidance and reviewed the manuscript. All authors read and approved the final manuscript.

Acknowledgements

The authors gratefully acknowledge the Department of Horticulture Science, Hajee Mohammad Danesh Science and Technology University, for providing facilities and support to complete this study.

Conflict of Interest Disclosure

The authors affirm that this research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest.

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