Growth Of Water Spinach Research Articles

Transcriptome analysis shows that Glomus versiforme decrease the accumulation and toxicity of cadmium in Ipomoea aquatic Forsk.

So far, the physiological and molecular mechanisms of the impact of arbuscular mycorrhizal fungus (AMF) on Cd absorption, transport and detoxification in Ipomoea aquatica (water spinach) are still unclear. In the present study, a pot experiment was performed to investigate the impact of AMF-Glomus versiforme (Gv) on the photosynthetic characteristics, Cd uptake, antioxidative system and transcriptome in water spinach in the soils supplemented with 5mg Cd kg-1. Gv inoculation improved significantly the photosynthetic characteristics and growth of water spinach. Furthermore, Gv colonization significantly promoted the activities of catalase (CAT), peroxidase (POD) and glutathione reductase (GR), contents of glutathione (GSH) and ascorbic acid (AsA), and the total antioxidant capacity (TCA), but decreased malondialdehyde (MDA) content in water spinach. In addition, Gv inoculation significantly increased pH in rhizosphere soils and decreased the Cd concentrations and uptakes in water spinach. Importantly, 2670 differentially expressed genes (DEGs) were screened in water spinach root colonized with Gv in 5mg Cd kg-1 soil, of which 2008 DEGs were upregulated and 662 DEGs were downregulated. Especially, the expression levels of POD, CAT, GR, dehydroascorbate reductase 2 (DHAR2), glutathione S-transferase U8 (GSTU8) and glutathione synthetase (GSHS) and cytochrome P450 (Cyt P450) genes were significantly up-regulated in water spinach inoculated with Gv. Meanwhile, the plant cadmium resistance protein 2 (PCR2), metal tolerance protein 4 (MTP4), ATP-binding cassette transporter C family member (ABCC), ABC-yeast cadmium factor 1 (ABC-YCF1) and metallothionein (MT) genes were also up-regulated in mycorrhizal water spinach. Our results firstly elucidated the mechanism by which AMF reduced the uptake and phytotoxicity of Cd in water spinach through a transcriptome analysis.

Post-Ratooning Water Spinach Growth and Production in Water Spinach Catfish Aquaponic Farming

Water spinach is a plant species that can be utilized for food diversification in Indonesia. Water spinach is among the plants that can be grown using an aquaponic system. Aquaponics is a method of cultivation that integrates fish and vegetable farming in a single location. Ratoon is a pruning technique that stimulates the growth of new shoots and is a supportive method for aquaponic cultivation. The use of foliar fertilizer is an approach to enhance the growth of water spinach in aquaponic systems. The objective of this research is to assess the impact of foliar fertilizer and stocking density on the growth of water spinach ratoon in aquaponics. The study employed a factorial Randomized Block Design (RAK) approach, with foliar fertilizer as the first factor and stocking density as the second factor. The findings indicated that foliar fertilizer application had a significant effect on nearly all variables, except for the number of leaves in the third ratoon, wet and dry weight of roots in the third ratoon, root volume in the third ratoon, and plant biomass. The most effective type of foliar fertilizer was found to be Growmore. The stocking density of catfish also had a notable impact on most variables, except for the plant height in the third ratoon, number of leaves in the third ratoon, stem diameter in the second ratoon, stem diameter in the third ratoon, and dry weight in the third ratoon. The optimal catfish stocking density was determined to be 15 catfish. The combined treatment of foliar fertilizer and catfish stocking density only showed a significant effect on certain variables, such as stem diameter in the second ratoon, root wet weight in the third ratoon, root volume in the third ratoon, and plant biomass. The highest average value was observed in the treatment combination of 15 catfish with Growmore fertilizer.

Smart Hydroponic Farming System Integrated with LED Grow Lights

Vertical farming, including hydroponics, is a growing trend in the agricultural sector due to the increasing demand for food and urbanisation. Thus, hydroponics can save space and achieve faster plant growth compared to traditional farming methods. The concept of smart farming has been applied in this study to improve the ease of control and monitoring of hydroponic systems. The effects of light-emitting diodes (LEDs), light distance, and colour (purple and white) on water spinach growth in a hydroponic system were investigated. Additionally, an Internet of Things (IoT) controller was developed and implemented to facilitate the use of the system in an indoor hydroponic-based environment system. Based on the results, the distance between the LED light of 15 cm and the plants and the colour of the LED light (white) can positively impact plant growth in a hydroponic system. Using an IoT controller also allows for continuous monitoring and control of factors that influence plant growth. Hence, this research would catalyse the local smart hydroponic farming system for improved deliverables.

Exceptional anti-toxic growth of water spinach in arsenic and cadmium co-contaminated soil remediated using biochar loaded with Bacillus aryabhattai

Functionalized biochars are crucial for simultaneous soil remediation and safe agricultural production. However, a comprehensive understanding of the remediation mechanism and crop safety is imperative. In this work, the all-in-one biochars loaded with a Bacillus aryabhattai (B10) were developed via physisorption (BBC) and sodium alginate embedding (EBC) for simultaneous toxic As and Cd stabilization in soil. The bacteria-loaded biochar composites significantly decreased exchangeable As and Cd fractions in co-contaminated soil, with enhanced residual fractions. Heavy metal bioavailability analysis showed a maximum CaCl2-As concentration decline of 63.51% and a CaCl2-Cd decline of 50.96%. At a 3% dosage of composite, rhizosphere soil showed improved organic matter, cation exchange capacity, and enzyme activity. The aboveground portion of water spinach grown in pots was edible, with final As and Cd contents (0.347 and 0.075 mg·kg⁻¹, respectively) meeting food safety standards. Microbial analysis revealed the composite's influence on the rhizosphere microbial community, favoring beneficial bacteria and reducing plant pathogenic fungi. Additionally, it increased functional microorganisms with heavy metal-resistant genes, limiting metal migration in plants and favoring its growth. Our research highlights an effective strategy for simultaneous As and Cd immobilization in soil and inhibition of heavy metal accumulation in vegetables.

Comparative of Shoot and Root Growth of Water Spinach (Ipomoea aquatica) Cultivated in Mars Global Simulant MGS-1 with or without Addition Earth Soil Illuminated by LED light in Indoor Environment

Mars has been a target for human colonization for centuries. When the time comes for humans to settle Mars, they will need food for survival. It is implausible to send a lot of fresh food to Mars. Therefore, we could instead cultivate plants at the site itself, using Martian soil in an indoor environment. In this study, we evaluated the shoot and root growth of water spinach (Ipomoea aquatica) in Mars Simulant or combination of Mars Simulant with earth soil at indoor environment using LED lighting. The result showed that water spinach can grow on earth soil and Mars Global Simulant MGS-1 for 28 days (about 4 weeks) without any addition of nutrients aside from water. Growth in earth soil is much better than on Mars Global Simulant MGS-1, and even 75 % Mars Global Simulant MGS-1: 25 % earth soil is slightly better than 100 % Mars Global Simulant MGS-1. The growth of water spinach shoots in Mars Simulant was compared to poor water spinach root growth in Mars Simulant. Our results provided the insight that it is possible to grow water spinach in Mars Simulant indoors and to boost its growth, physical properties and chemical composition of Mars Simulant improvement was needed.

Water Spinach (Ipomoea aquatica F.) Effectively Absorbs and Accumulates Microplastics at the Micron Level—A Study of the Co-Exposure to Microplastics with Varying Particle Sizes

The absorption of microplastics (MPs; size < 5 mm) by plants has garnered increasing global attention owing to its potential implications for food safety. However, the extent to which leafy vegetables can absorb large amounts of MPs, particularly those > 1 μm, remains insufficiently demonstrated. To address this gap in knowledge, we conducted water culture experiments using water spinach (Ipomoea aquatica F.) as a model plant. The roots of water spinach were exposed to a mixed solution that contained fluorescently labeled polystyrene (PS) beads with particle sizes of 200 nm and 1 μm for 10 d. We utilized laser confocal scanning microscopy and scanning electron microscopy to record the absorption, migration, and patterns of accumulation of these large particle sizes of MPs within water spinach. Our findings revealed that micron-sized PS beads were absorbed by the roots in the presence of submicron PS beads and subsequently transported through the exosomes to accumulate to significant levels in the leaves. Short-term hydroponic experiments further indicated that high concentrations of PS bead solutions significantly inhibited the growth of water spinach owing to their large specific surface area that hindered the uptake of water and nutrients by the roots. In conclusion, both sizes of PS beads were found to be absorbed by water spinach, thereby increasing the risk associated with direct human consumption of microplastics in fruits and vegetables. This study provides valuable scientific insights to assess the pollution risks related to fruits and vegetables, as well as ensuring vegetable safety.

Removal and recovery of phosphate by modified oyster shell and its fertilizer application

The resource utilization of oyster shell (OS) is essential for environmental and human health because its random disposal can induce the environmental pollution and disease spread. Herein, MnFe2O4 loaded-oyster shell (OMFs) was prepared by co-precipitation method for phosphate removal and recovery. The salt etching and MnFe2O4 (MF) loading improved the adsorption performance of OS, and the maximum adsorption capacity of OMF0.02 reached 87.39 mg P/g. Phosphate adsorption was dominated by chemisorption and its rate was limited by membrane diffusion and intra-particle diffusion. Phosphate adsorption by OMF0.02 was involved with electrostatic attraction, surface precipitation and ligand exchange. 98.95 % phosphate on saturated adsorbent could be desorbed by 0.1 mol/L malic acid and 92.31 % adsorbed phosphate was released by 0.5 mol/L NaHCO3. Furthermore, phosphate adsorbed on OMF0.02 was plant-available basing on the results of water spinach growth trial. All the results implied the bright prospect of OMF0.02 in phosphate removal and recovery from wastewater.

L-DOPA induces iron accumulation in roots of Ipomoea aquatica and Arabidopsis thaliana in a pH-dependent manner

BackgroundIron deficiency is the leading cause of anemia worldwide, particularly in countries with predominant plant-based diets. Plants constitute the main source of dietary iron. Increasing their iron concentration could reduce the occurrence of anemia. The water spinach Ipomoea aquatica is consumed as a vegetable throughout Asia and tolerates high iron concentrations making it an attractive candidate for iron biofortification. L-DOPA is an allelopathic molecule secreted by some legumes. L-DOPA can trigger the expression of Fe deficiency-inducible genes, and could potentially be used as a biostimulant to increase Fe concentration.ResultsL-DOPA significantly affected root growth of water spinach, and triggered a massive accumulation of Fe in roots. Both effects were exacerbated when L-DOPA was dissolved in KOH, which is surprising given that L-DOPA is less stable at high pH. To check whether a higher pH could indeed increase the bioactivity of L-DOPA, we used Arabidopsis thaliana, which grows at lower pH than water spinach, and subjected the plants to L-DOPA treatments at pH 5.5 and pH 6.0, which are both within the optimal range for Arabidopsis nutrition. At pH 6.0, the root growth of Arabidopsis was more strongly inhibited than at pH 5.5. We found that at higher pH, L-DOPA oxidizes to form a melanin precipitate.ConclusionsWe concluded that the oxidation of L-DOPA that we observed upon solubilization in KOH, or in nutrient solutions at slightly higher pH produces melanin-related molecules that are more potent than L-DOPA itself to trigger the primary root growth inhibition, Fe uptake and root Fe accumulation in water spinach and Arabidopsis.

Effect of Heat Stress on Root Architecture, Photosynthesis, and Antioxidant Profile of Water Spinach (Ipomoea aquatica Forsk) Seedlings

Crop productivity around the world is being seriously affected by adverse environmental conditions. High temperature (HT) stress has severely hampered plant growth, yield, and quality. Water spinach is a significant heat-resilient green leafy vegetable that can mitigate prolonged HT stress. However, the morphological, physiological, and biochemical alterations that occur in its response to heat stress remain unknown. In this study, the physiological response to HT stress in water spinach plants with different temperature (25-control, 30, 35, 40, 45 °C) tolerances was investigated. When plants were subjected to HT over a long period of time, their growth was stunted. The results showed that no significant difference was seen between the control (25 °C) and 30 °C for some traits (root shoot fresh weight, root morphological traits, and leaf gas exchanges parameters). Further, HT (35, 40, and 45 °C) stress significantly reduced the growth status, the gas exchange parameters, the pigment content, the photosystem function, and the root architecture system of water spinach. Conversely, HT stress considerably enhanced secondary metabolites in terms of total phenolics, flavonoids, soluble sugars, and anthocyanin content. Furthermore, heat stress remarkably increased the accumulation of reactive oxygen species (ROS) and caused cellular membrane damage. HT stress effectively altered the antioxidant defense system and caused oxidative damage. Generally, HT has an adverse effect on the enzyme activity of water spinach, leading to cell death. However, the current study found that temperatures ≥35 °C had an adverse effect on the growth of water spinach. Further research will be needed to examine the mechanism and the gene expression involved in the cell death that is caused by temperature stress in water spinach plants.

The effect of organic matter on soil organic carbon and water spinach grown in gold mine tailings

The disposal of tailings generated from mining activities poses environmental challenges due to their low fertility and limited suitability for plant growth. This study aimed to investigate the potential of cow manure application in improving the organic-C content of tailings and enhancing the growth of water spinach (Ipomoea reptans). This experiment was laid out in a randomized block design with five treatments and five replications. The treatments involved the application of cow manure at different doses and control, which consisted of; (A) Control, (B) 150 g, (C) 300 g, (D) 450 g, (E) 600 g. The results revealed a significant increase in the organic-C content of tailings following the application of cow manure. The highest organic-C content of 7.47% was achieved with the application of 600 g of cow manure. The application of 150 g of cow manure resulted in the tallest plants with higher fresh and dry weights. The findings from this study underscore the importance of organic amendments in enhancing the organic-C content and promoting plant growth in low fertility growth medium. Further research on the long-term effects and optimization of cow manure application in tailing-based growth substrates is recommended to enhance soil fertility and maximize plant productivity.

Effect of cow manure mon the growth of water spinach in gold mine tailing

Gold mining activities produce abundant tailings waste. The negative impacts of tailing pollution on agriculture include soil profile loss, soil compaction, depletion of essential nutrients, organic matter, and soil pH, making it difficult for plants to grow. Cow manure (CM) is a well-known soil amendment to improve soil quality and facilitate root growth. Animal manure fertilizers contain a complete range of macro and micronutrients required by plants. In addition to its ability to enhance soil fertility, CM can also promote plant growth in former mining areas or mineral tailings. The objective of this study was to determine the effect of CM application rates on water spinach plant growth improvement. The experimental design used was a Completely Randomized Block Design (CRBD) with four treatments and six replications. The experimental treatments consisted of a control (without treatment), 10 t ha-1, 20 t ha-1, and 30 t ha-1 of CM. The results of the experiment showed that CM application increased plant height, leaf count, stem diameter, and wet weight of water spinach plants. The application of 10 t ha-1 CM showed the highest growth improvement in terms of plant height, leaf count, stem diameter, and wet weight of plants grown in gold mining tailings compared to other treatments. This experiment highlights the importance of CM for water spinach cultivation in tailing areas.

Nitrogen and Phosphorus Co-Doped Carbon Dots for the Growth Promotion of Water Spinach

Carbon dots have received much attention due to their unique physicochemical properties and diverse applications in bioimaging, optoelectronic devices, catalysis, and agriculture. Here, in this work, we report a simple hydrothermal synthesis of nitrogen and phosphorus−doped carbon dots (N, P−CDs). The optical and physical properties of the synthesized N, P−CDs are analyzed using systematical spectroscopy and electrical characterization. The synthesized N, P−CDs show strong photoluminescence at 626 nm and demonstrate high stability under UV light and other conditions. Moreover, we incorporate the synthesized N, P−CDs into water spinach by root spraying and leaf spraying. It is found that N, P−CDs could effectively promote the growth of water spinach by accelerating the photosynthetic rate, and increasing the content of total phenols, anthocyanins, and flavonoids in water spinach.

Utilization of palm oil mill effluent as growth media in budikdamber system

Palm oil mill effuent (POME) has the potential to become an environmental pollutant if left unutilized. This study aims to examine the effect of POME on catfish and water spinach growth in the bucket fish culture system (budikdamber). This research was conducted in August-November 2021, and comprises of acclimatization of fish, seeding, POME media preparation, rearing, observation, and data analysis. This study used a completely randomized design, consisting of four treatments and three replications. The treatments was the POME concentrations, consisting of Control (0 mg.L−1), A (1.565 mg.L−1), B (2.347 mg.L−1), and C (3.130 mg.L−1). The fish used were catfish measuring 5-7 cm totaling 20 fish/bucket, while the plant used was seedlings measuring 2-3 cm. Data were analyzed using one-way ANOVA at 95% confidence level. The research parameters included the catfish Specific Growth Rate (SGR) and Survival Rate (SR), along with the height, number of branches, and leaves of water spinach. The results showed that the concentration of 3.130 mg.L−1 caused significant differences in fish and plant growth parameters. SGR of catfish decreased significantly at concentrations of 2.347 and 3.130 mg.L−1, meanwhile, SR of catfish was not significantly different. Concentrations of 1.565, 2.347, and 3.130 mg.L−1 showed a significant increase in height, branches, and leaves number of water spinach plants.

Zeolite Integrate with Natural Absorbance to Increase Crop Production

Mesoporous structure of Zeolites particles with higher micropores able to provide higher surface area that able to increase the efficiency of diffusion mechnism as well as cation exchange capacity (CEC). Theuniquness and unreactive properties of zeolites enable to integrate this materials with other potential material to increase the zeolite absorption and CEC performance. Thus, the goal of this work is to study the effect of natural absorbents(chitosan and charcoal) when integrate with zeolite that function as a soil enhancer for the plants growth. Several experiments at different composition of soil, fertilizer, zeolite and absorbance compositions towards water spinach growth, pH and soil humidity were measured. The results of the plant growth show that both natural absorbance materials significantly assist the nutrient uptake either from the soil or fertilizer by showing higher plant growth, pH and humidity values as compared to soil mixedwith fertilizeronly. Integration of these absorbance with zeolite futher increase the capability of nutrient uptake by giving the highest value of plant growth, pH and humidity values. Detail observation also showed that water spinach grew faster in the sample that had fertilizer added to the zeolite with charcoal as compared to chitosanKeywords:Zeolites, natural absorbance, charcoal, chitosan, pH, humidity, plant growth

Fabrication of a carbon cloth-based FeS nanosystem for simultaneous removal of Cr(VI) and microplastics

As two kinds of environmental pollutants, hexavalent chromium (Cr(VI)) and microplastics could be simultaneously released into the environment through agricultural production, industrial wastewater, and domestic sewage, resulting in combined pollution. Therefore, it was an important challenge to remove both Cr(VI) and microplastics simultaneously and effectively reduce their environmental impacts. In this study, ferrous sulfide (FeS) was fabricated by hydrothermal treatment and uniformly loaded on the surface of carbon cloth (CC) by using the conductive carbon paint (CCP) to obtain a nanosystem named as CC/CCP/FeS. Therein, FeS could provide electrons and have a high reduction capability for Cr(VI). CC could decrease the impedance of the nanosystem to 30 Ω, accelerate the transfer of electrons, and effectively solve the agglomeration of FeS. Importantly, CC/CCP/FeS could remove both Cr(VI) and microplastics in water at the same time, after which the resulting system could be conveniently separated from the water. The removal efficiencies of CC/CCP/FeS with nine layers for Cr(VI) and microplastics could reach 96 and 100 % by filtration, respectively. Additionally, pot experiment results indicated that CC/CCP/FeS could promote the growth of water spinach and reduce its Cr content from 273 to 31 mg/kg. Therefore, this research provides an effective method to simultaneously remove Cr(VI) and microplastics, which may have a huge application prospect for industrial wastewater treatment.

The Effects of Fly Ash and Cow Manure on Water Spinach Grown on An Ultisol of Lampung, Indonesia

Fly ash is the residue of coal combustion that can potentially be an ameliorant. Unfortunately, its use is limited by government regulations that are classified as hazardous and toxic materials. This study examines the effectiveness of fly ash and cow manure as an ameliorant for Ultisols. The experiment was carried out by two factors, i.e., the dose of fly ash, namely 0, 50, 100, and 150 t/ha, and the quantity of cow manure, i.e., 10, 20, and 30 t/ha. The results show that fly ash and cow manure could be ameliorants for low-pH soils such as Ultisols. The suitable dose of fly ash and cow manure as ameliorants in this study are 50 t/ha and 20 t/ha, respectively. Increasing the amount of fly ash caused a decrease in the growth of water spinach, plant height, number of leaves, fresh plant weight, root length, and dry weight of the root. In addition, fly ash increased pH 6.66-7.30, total P 31.74-52.21 mg/100 g, and total K 16.19-25.75 mg/100 g.

Potential impact of polyethylene microplastics on the growth of water spinach (Ipomoea aquatica F.): Endophyte and rhizosphere effects

Microplastic contamination has received much attention, especially in agroecosystems. However, since edible crops with different genetic backgrounds may present different responses to microplastics, more research should be conducted and focused on more edible crops. In the current study, pot experiments were conducted to investigate the potential impact of polyethylene microplastic (PE) (particle sizes: 0.5 μm and 1.0 μm, addition levels: 0 (control), 0.5% and 1.0% (w/w)) addition on the physiological and biochemical variations of I. aquatica F.. The results indicated that PE addition caused an increase in the soil pH and NH4+-N and soil organic matter contents, which increased by 10.1%, 29.9% and 50.1% when PE addition at A10P0.5 level (10 g (PE) kg−1 soil, particle size: 0.5 μm). While, PE exposure resulted in a decrease in soil available phosphorus and total phosphorus contents, which decreased by 53.9% and 10.5% when PE addition at A10P0.5 level. In addition, PE addition altered the soil enzyme activities. Two-way ANOVA indicated that particle size had a greater impact on the variations in soil properties and enzyme activities than the addition level. PE addition had a strong impact on the rhizosphere microbial and root endophyte community diversity and structure of I. aquatica F.. Two-way ANOVA results indicated that the particle size and addition level significantly altered the α-diversity indices of both rhizosphere microbial and root endophyte (P < 0.05, P < 0.01 or P < 0.001). Moreover, PE was adsorbed by I. aquatica F., which was clearly observed in the transverse roots and significantly increased the H2O2, ·O2−, malondialdehyde and ascorbic acid contents in both the roots and aerial parts of I. aquatica F., leading to a decrease in I. aquatica F. biomass. Overall, the current study enriches the understanding of the effect of microplastics on edible crops.

PENGARUH PUPUK KANDANG AYAM TERHADAP PERTUMBUHAN KANGKUNG (Ipomoea reptans Poir.) DAN IKAN LELE (Clarias gariepinus) SECARA AKUAPONIK SERTA SUMBANGANNYA PADA PEMBELAJARAN BIOLOGI SMA

The research aims to determine the effect of chicken manure fertilize on the growth of Kale plant (Ipomoea reptans Poir.) and catfish (Clarias gariepinus) with aquaponic. The research employed a completely randomized design consisting of five treatments and five replications. The treatments consisted of P0 (0 g/l), P1 (0,25 g/l), P2 (0,50 g/l), P3 (0,75 g/l) and P4 (1 g/l). The data of the research were analyzed using the ANOVA test and advanced tests with Least Significant Difference (LSD). The results showed that the dose of chicken manure as much as 0.25 g/l (P1) gave the best results for the growth of water spinach and sangkuriang catfish. The average wet weight of shoots and roots of kale was 178.13 g and 32.69 g, respectively, while the dry weight of the shoots was 8.99 g, and the dry weight of the roots was 1.99 g. As for an average fish weight growth rate 105,82 grams and an average total length of fish 5,87 cm. Based on the results of the study, it can be concluded that chicken manure fertilizer gives a real effect on the growth of kale and catfish which is kept with aquaponic technique. The results of this research can be utilized on biology learning in class XII on basic competencies 3.1 and 4.1 about growth and development of living things that are donated in the form of teaching material in the form of student worksheets.

Pertumbuhan dan Produksi Kangkung Hidroponik Sistem DFT pada Media Semai dan Jumlah Bibit yang Berbeda Growth and Production of Water Spinach Hydroponics DFT Sistem on Seedling Media and Different Number of Seeds

Water spinach can be grown hydroponically using the DFT system. Seeding is needed before the seeds are transplanted, so it is necessary to select the appropriate seedling media because it will determine the initial growth of water spinach. The number of seeds per netpot also needs to be regulated because it affects the competition for growing space, nutrient absorption and sunlight reception. The purpose of this study was to determine the effect of seedling media and the number of seeds per netpot on the growth and production of water spinach in the DFT hydroponic system. The experiment was carried out in the Balitsa Lembang screen house from March to April 2022. The experiment used a two-factor randomized design with 3 replications. The first factor of seedling media consisted of: soil + cow manure, soil + sheep manure, and soil + subur ijo organic fertilizer. The second factor is the number of seeds per netpot consisting of: 6, 8, and 10 seeds. The results showed that the soil seedling media + sheep manure produced the highest seedling growth rate of 76.67%. 6 seedlings per netpot yielded the highest percentage of live plants, which was 96%. 6 seedlings per netpot resulted in higher plant height, stem diameter, plant weight, and harvest index than 10 seedlings, but not significantly different from 8 seedlings. Soil seedling media + sheep manure and 6 seeds per netpot can be used in DFT hydroponic cultivation of water spinach to increase production and save plant seeds.

Effects of Sound Wave and Water Management on Growth and Cd Accumulation by Water Spinach (Ipomoea aquatica Forsk.)

Vegetable contamination by cadmium (Cd) is of great concern. Water spinach (Ipomoea aquatica) is a common leafy vegetable in many countries and has a strong ability to accumulate Cd. The work was conducted to study the effects of sound wave, water management, and their combination on Cd accumulation and growth of water spinach, using the following three experiments: a hydroponic trial with the treatment of a plant acoustic frequency technology (PAFT) generator in test sheds, a hydroponic trial with three music treatments (electronic music (EM), rock music (RM), and classical music (CM)) in artificial climate boxes, and a soil pot trial with treatments of PAFT and EM under non-flooded and flooded conditions. The results showed that the hydroponic treatments of PAFT and EM significantly reduced the Cd concentrations in roots and shoots (edible parts) of water spinach by 22.01–36.50% compared with the control, possibly due to sound waves decreasing the root tip number per unit area and increasing average root diameter, root surface area, and total root length. Sound wave treatments clearly enhanced water spinach biomass by 28.27–38.32% in the hydroponic experiments. In the soil experiment, the flooded treatment significantly reduced the Cd concentrations in roots and shoots by 43.75–63.75%, compared with the non-flooded treatment. The Cd decrease and the biomass increase were further driven by the PAFT supplement under the flooding condition, likely related to the alteration in root porosity, rates of radial oxygen loss, extractable soil Cd, soil Eh, and soil pH. Our results indicate that the co-application of plant acoustic frequency technology and flooded management may be an effective approach to reduce Cd accumulation in water spinach.