Concentration In Nutrient Solution Research Articles

Nutrient Uptake, Partitioning, and Production of Two Subspecies of Brassica using Different Solution Concentrates in Floating Hydroponics Systems

In this study, we investigated nutrient uptake, partitioning, and production of two subspecies of Brassica in response to nutrient solution concentration in floating hydroponics systems. This study used a complete randomized block design factorial with two factors. The first factor was two Brassica subspecies consisting of Brassica rapa subsp. chinensis (Pak Choi) and Brassica rapa var. parachinensis (Choy Sum). The second factor was the concentration level consisting electrical conductivity (EC) 1 mS cm-1 and EC 2 mS cm-1. The results indicated the absorption rates of nitrogen (N,) phosphorus (P), and potassium (K) in leaves, roots and stems were similar in both nutrient concentrations. In general, all combination treatments resulted more accumulation of P followed by N, also K as the smallest proportion. P was mostly accumulated at the root and leaves (19.60 to 25.90 mg g-1), while majority of N was collected in leaves ranging from 18.00 to 24.30 mg g-1. The highest K content was detected in the stem (10.70 to 14.20 mg g-1). P uptake was 1.69 to 2.47 times higher than K, while N uptake was 1.44 to 2.04 times higher than K. Both two subspecies and concentrations performed no significant effects on nutrient uptake. Although same species, the plant growth parameters of Pak Choi and Choy Sum are very different including plant height, leaves number, width and length. Both two subspecies adapted well with both concentrations. However, significant differences were recorded in the combination of subspecies and nutrient concentration on plant growth and production parameters. To achieve higher market portion, Pak Choi would be more suitable to be planted on EC 1 mS cm-1, while Choy Sum was favorable at both concentrations.

Determination and Evaluation of Se-Rich High-Quality Rice Produced by Compound Nutrient Solution

Rice is one of the most important food crops in the world. Its biggest flaw is the low content of protein and essential amino acids, which severely limits its nutritional value. In order to produce high-quality rice with rich Se, we sprayed different concentrations of compound nutrient solution (containing Se (selenium), amino acid compound, zinc and boron) on the rice at different growth stages; and then determined the main nutrient content of their polished rice. The results showed that spraying low concentration compound nutrient solution (Each liter contained 20 mg of Se, 333 mg of complex amino acids, 33 mg of zinc and 33 mg of boron) to rice in the heading stage produced rice with the highest total starch and fat content and lower amylose content. Spraying high concentration compound nutrient solution to rice during the filling stage produced rice with the highest Se content. Multiple sprays of compound nutrient solution produced rice with low protein and low starch. Spraying low concentration compound nutrient solution on rice in milky stage significantly increased the content of protein, total starch, fat, all essential amino acids (Lysine increased by more than 57%), amylopectin and Se in rice; significantly reduced amylose content; significantly improved the nutritional value and taste quality of rice. The conclusion is that spraying low concentration compound nutrient solution on rice in the milky stage can produce rice with the highest content of protein and essential amino acids, higher content of total starch, fat and Se, and the lowest amylose content; significantly improve the nutritional value and taste quality of rice. The technical solution can comprehensively and effectively improve the nutritional value and flavor quality of rice, and has great development and application value.

Exposure of Typha domingensis to high concentrations of multi-metal and nutrient solutions: Study of tolerance and removal efficiency

This work studied the effects of nutrients on metal tolerance, removal efficiency, and metal accumulation in tissues of T. domingensis. This macrophyte was exposed to solutions of Cr(III) + Ni + Zn at extremely high concentrations. Treatments were metal combinations of 200 or 600 mg L−1 of each metal with and without nutrients (N and P). Treatment 600 exhibited significantly lower final metal removals than those of 200. The highest removal from water in all treatments was registered for Cr. Final Cr removal did not show significant differences between the treatments with and without nutrient addition. Sediment showed higher concentrations than plant tissues. Roots exhibited the highest Cr concentrations in tissues. In comparison with roots, leaves did not show significant differences in Ni and Zn concentrations, except for 200 and 200 + nutrient. Treatments with nutrient addition reached a significantly higher relative growth rate (RGR) than that obtained in treatments without nutrient addition. Treatments 600 and 600 + nutrients showed a significantly lower RGR than that of treatments 200 and 200 + nutrients. In Treatment 600 the lowest chlorophyll concentration was observed. T. domingensis demonstrated its ability to survive a fortuitous industrial dump of high metal concentrations in a treatment wetland.

Utilizing Anaerobic Digestates as Nutrient Solutions in Hydroponic Production Systems

Moving food production into the urban and peri-urban areas is one way of facilitating a closed-loop approach, integrating waste handling with food production in order to recirculate nutrients and at the same time reduce the use of mined and fossil resources in the production. Using anaerobic digestion as a way of converting urban wastes to an energy source (methane) and a nutrient-rich biodigestate with subsequent use as fertilizer for food production seems like a feasible approach. However, utilizing urban wastes in plant production systems implies some challenges, such as high salinity of the waste, imbalanced composition of nutrients, and abundance of less favorable forms of nitrogen. In a series of experiments, these problems were addressed. Vegetables (Pak Choi) were cultivated hydroponically in a controlled climate. Experiments included increased salinity, elevated levels of nitrite, and different concentrations of the biogas digestate-based nutrient solution, with mineral based solutions as controls. In general, the mineral controls yielded around 50% higher fresh biomass than the organic solutions. However, the quality of the produce with respect to content of secondary metabolites such as vitamins was enhanced when the plants were cultivated with organic nutrient solutions. Increasing the concentration of NaCl to 241 mg Cl L−1 did not negatively affect plant performance. Increasing the concentration of nitrite negatively affected plant growth, with reductions in biomass production by up to 50%. Given this well-functioning nitrification process that did not result in high nitrite concentrations, the use of anaerobic digestates seems feasible for hydroponic production of vegetables.

Pengaruh Penambahan Ca(NO3)2 Terhadap Hasil Tanaman Selada Kriting (Lactuca Sativa L.) pada Sistem Hidroponik Deep Flow Technique (DFT)

The Effect of Addition of Ca(NO3)2 to the Results of Lettuce (Lactuca sativa L.) in the Hydroponic System of Deep Flow Technique (DFT). Plants, in general, require composition, concentration, and volume of nutrient solutions which different depends on the type and phase of plant growth. Leaf vegetable crops such as lettuce (Lactuca sativa L.) require higher Nitrogen (N) nutrients than other vegetable crops, but the problem we faced at the moment is the hydroponic nutrients that are traded only in the general form of nutrient, therefore the addition of N nutrients in the form of calcium nitrate (Ca(NO3)2) needs to be done to meet the needs of lettuce plants. This study was aimed to determine the effect of the addition of Ca(NO3)2 and to find the optimum dosage of the addition of Ca(NO3)2 to the general hydroponic nutrition of vegetables on lettuce use DFT hydroponic system. The treatments consisted of five levels which are nutrition AB Mix general vegetable as a control, and nutrition AB Mix with the addition of 30 g, 60 g, 90 g, and 120 g Ca(NO3)2. The results of the observation showed that the treatment of the addition of Ca(NO3)2 fertilizer had a very significant effect on all observed variables, except for the diameter of the lettuce plant. The optimum addition of Ca(NO3)2 for lettuce was found at 90.04 g with a maximum yield of 207.92 g.

Production of Soybean Plants for Hydroponic Cultivation from Seedling Cuttings in a Medium Containing Rhizobium Inoculum Depending on Various Concentrations of Nutrient Solution and Different Nitrogen Sources

Abstract There has been an increasing interest in soybean cultivation in hydroponic systems. Because soybean plants can utilize nitrogen derived from biological N2 fixation, the use of Rhizobium inoculated plants may eliminate or decrease the need for mineral nitrogen fertilization in hydroponic systems. Thus, the objective of this study was to establish effective methods for making inoculated soybean transplants for a substrate-based hydroponic system. Inoculated plants were effectively produced by rooting seedling stem cuttings in a medium containing a Rhizobium inoculant. We also investigated the effects of different nitrogen forms and sub-irrigated nutrient solution concentrations on the growth and root nodule formation of the inoculated plants. The application of a nitrogen-free nutrient solution had minimal positive effects on the growth and nodulation of the inoculated plants. Ammonium-fed plants lacked root nodules regardless of the ammonium concentration. Furthermore, a 50% nutrient solution combining with nitrate or urea as the nitrogen source did not promote root nodulation. Therefore, inoculated plants should be subirrigated with an approximately 25% nutrient solution supplemented with nitrate or urea to induce early growth and nodulation prior to transplantation.

Effect of Nutrient Solution Concentration on the Growth of Hydroponic Sweetpotato

Nutrient solution concentration (NSC) is a critical factor affecting plant growth in hydroponics. Here, we investigated the effects of hydroponic NSC on the growth and yield of sweetpotato (Ipomoea batatas (L.) Lam.) plants. First, sweetpotato cuttings were cultivated hydroponically in three different NSCs with low, medium, or high electrical conductivity (EC; 0.8, 1.4, and 2.6 dS m−1, respectively). Shoot growth and storage root yield increased at 143 days after plantation (DAP), depending on the NSC. Next, we examined the effect of NSC changes at half of the cultivation period on the growth and yield, using high and low NSC conditions. In plants transferred from high to low EC (HL plants), the number of attached leaves increased toward the end of the first half of the cultivation period (73 DAP), compared with plants transferred from low to high EC (LH plants). Additionally, the number of attached leaves decreased in HL plants from 73 DAP to the end of the cultivation period (155 DAP), whereas this value increased in LH plants. These changes occurred due to a high leaf abscission ratio in HL plants. The storage root yield showed no significant difference between HL and LH plants. Our results suggest that the regulation of hydroponic NSC during the cultivation period affects the growth characteristics of sweetpotato.

Optimization of Light Intensity, Temperature, and Nutrients to Enhance the Bioactive Content of Hyperforin and Rutin in St. John's Wort.

St. John’s wort (Hypericum perforatum L.) is a medicinal plant that alleviates depression and other disorders due to its abundance of active ingredients. Hyperforin, rutin, and melatonin are the main active, and important, ingredients in St. John’s wort that alleviate depression. In order to investigate the optimal conditions for accumulating these active ingredients, design of experiments and response surface methodology (RSM) was employed in this study. Two-month-old St John’s wort plants were cultivated in growth chambers at varying temperatures, light intensities, and nutrient solution concentrations before analysis by HPLC, for determining differences in hyperforin, rutin, and melatonin content. The results showed that hyperforin and rutin contents were significantly influenced by temperature (18–23 °C) and light intensity (49–147 μmol m−2 s−1 photosynthetic photon flux density (PPFD)), whereas Hoagland’s nutrient solution concentration (25–75%) had little effect. The accumulation of melatonin might not be influenced by cultivation conditions. Light intensity and temperature are easily controlled environmental factors in artificial cultivation, both of which are related to secondary metabolite production in the plant. Based on RSM, the optimal conditions for the accumulation of hyperforin and rutin were obtained. The maximum content of hyperforin was 5.6 mg/g, obtained at a temperature of 19 °C, a nutrient solution concentration of 45%, and a light intensity of 49 μmol m−2 s−1 PPFD. The maximum content of rutin was 3.8 mg/g obtained at a temperature of 18 °C, a nutrient solution concentration of 50%, and a light intensity of 147 μmol m−2 s−1 PPFD. This evaluation of suitable conditions for the accumulation of bioactive compounds in St. John’s wort can be applied to plant factories on a large scale.

Strategies for Improved Yield and Water Use Efficiency of Lettuce (Lactuca sativa L.) through Simplified Soilless Cultivation under Semi-Arid Climate

Simplified soilless cultivation (SSC) systems have globally spread as growing solutions for low fertility soil regions, low availability of water irrigation, small areas and polluted environments. In the present study, four independent experiments were conducted for assessing the applicability of SSC in the northeast of Brazil (NE-Brazil) and the central dry zone of Myanmar (CDZ-Myanmar). In the first two experiments, the potentiality for lettuce crop production and water use efficiency (WUE) in an SSC system compared to traditional on-soil cultivation was addressed. Then, the definition of how main crop features (cultivar, nutrient solution concentration, system orientation and crop position) within the SSC system affect productivity was evidenced. The adoption of SSC improved yield (+35% and +72%, in NE-Brazil and CDZ-Myanmar) and WUE (7.7 and 2.7 times higher, in NE-Brazil and CDZ-Myanmar) as compared to traditional on-soil cultivation. In NE-Brazil, an eastern orientation of the system enabled achievement of higher yield for some selected lettuce cultivars. Furthermore, in both the considered contexts, a lower concentration of the nutrient solution (1.2 vs. 1.8 dS m−1) and an upper plant position within the SSC system enabled achievement of higher yield and WUE. The experiments validate the applicability of SSC technologies for lettuce cultivation in tropical areas.

Iron deficient Medicago scutellata grown in nutrient solution at high pH accumulates and secretes large amounts of flavins

Flavin synthesis and secretion is an integral part of the toolbox of root-borne Fe facilitators used by Strategy I species upon Fe deficiency. The Fe-deficiency responses of the wild legume Medicago scutellata grown in nutrient solution have been studied at two different pH values (5.5 and 7.5). Parameters studied include leaf chlorophyll, nutrient solution pH, concentrations and contents of micronutrients, flavin accumulation in roots, flavin export to the medium, and root ferric chelate reductase and acidification activities. Results show that M. scutellata behaves upon Fe deficiency as a Strategy I species, with a marked capacity for synthesizing flavins (riboflavin and three hydroxylated riboflavin derivatives), which becomes more intense at high pH. Results also show that this species is capable of exporting a large amount of flavins to the external medium, both at pH 5.5 and 7.5. This is the first report of a species having a major flavin secretion at pH 7.5, in contrast with the very low flavin secretion found in other flavin-producing species such as Beta vulgaris and M. truncatula. These results provide further support to the hypothesis that flavin secretion is relevant for Fe acquisition at high pH, and open the possibility to improve the Fe-efficiency responses in legumes of agronomic interest.

Optimization of light intensity and nitrogen concentration in solutions regulating yield, vitamin C, and nitrate content of lettuce

ABSTRACT Light intensity and nitrogen concentration in nutrient solutions are two main factors affecting the growth and nutritional quality of lettuce(Lactuca sativa L.). This study investigated the method of regulating vegetable cultivation through the interactive control of the light environment and solution ratio. A quadratic regression orthogonal model was developed to understand the role of light intensity (43 to 237 µmol m−2s−1) and nitrogen concentration (4.3 to 23.7 mmol L−1) in lettuce growth. Dry weight, vitamin C, and nitrate contents were measured and modelled to understand the coupling effect of light intensity and nitrogen concentration on lettuce. The optimised conditions for lettuce growth were 237 µmol m−2 s−1 of light intensity and 9.2 mmol L−1 of nitrogen concentration, and these conditions were predicted to produce lettuce with an average dry biomass of 3.9 g plant−1, 149.9 µg g−1 of Vitamin C, and 212.1 µg g−1 of nitrate content based on their respective weighting factors (0.50, 0.25, and 0.25). The lettuce yield and quality were verified using the modelled optimised growth conditions and the lettuce grown was indeed more nutritional compared to the commercially available lettuce. The findings are important for mass production of lettuce in plant factories and greenhouses.

Effects of salinity on growth, competitive interaction and total nitrogen content of two estuarine macrophyte species cultivated on artificial substrate

Salinity can compromise the growth of aquatic macrophytes, influencing their nutrient content and interspecific interactions. In estuaries, the sediment characteristics vary in salinity as well as nutrient availability, granulometry and microbiota. The use of artificial substrates in manipulative experiments allows the evaluation of the isolated effect of salinity on plants. We evaluated the effects of salinity on growth, interspecific interaction and total nitrogen (TN) content of the estuarine macrophytes Spartina alterniflora and Crinum americanum cultivated on expanded vermiculite. We conducted a two-factor experiment (3 cultures × 3 salinities × 5 replicates = 45 experimental units) lasting 185 days in a greenhouse. We cultivated monocultures (8:0 and 0:8) and mixed cultures (4:4) at 0, 20 and 30 ppt salinity levels with the same concentration of nutrient solution. We found that salinity did not influence the growth of S. alterniflora and C. americanum in monoculture. In mixed culture, there was an asymmetric competition, as S. alterniflora limited the growth of the aboveground fraction of C. americanum at higher salinity; however, C. americanum did not limit the growth of S. alterniflora at any treatment. Salinity did not influence the TN content in S. alterniflora. However, C. americanum had greater TN content in the aboveground fraction at higher salinity, possibly as a strategy of salt tolerance. The TN content in the aboveground fraction of C. americanum was lower in the mixed cultures than in the monocultures, indicating an effect of the interspecific interaction.

PENGARUH PENAMBAHAN KALIUM NITRAT DALAM LARUTAN HARA PADA MEDIA KASCING TERHADAP PERTUMBUHAN SELADA (Lactuca sativa L.)

This research was conducted with the aim to find out the effect of the addition of potassium nitrate in lettuce as a medium and critical level of concentration(electrical conductivity)of nutrient solution. Research is organized in the form of a pot experiment. The experimental design used was Complete RandomizedBlock Design (CRBD)) with three replications. The treatment consists of 12 levels of concentrations or nutrient solution electrical conductivity with the addition of potassium nitrate to lettuce plant. The treatment level of concentrations (conductivity) of nutrient is as follows; L0 = 0.00; L1 = 1.25; L2 = 2.50; L3 = 3.75; L4 = 5.00; L5 = 6.25; L6 = 7.50; L7 = 8.75; L8 = 10.00; L9 = 11.25; L10 = 12.50 and L1 = 13, 75 g 100 L-1 water. Value concentrations of electrical conductivity each nutrient solution concentrations are: L0 = 0.06; L1 = 0.26; L2 = 0.46; L3 = 0.66; L4 = 0.86; L5 = 1.06; L6 = 1.26; L7 = 1,46; L8 = 1.66; L9 = 1,86; L10 = 2.06 and L1 = 2.26. dS m-1. The result of the experiment showed that addition of KNO3 highly significant effect on the increase in fresh weight and dry weight of shoot per plant. Fresh weight and oven-dry weight of shoot per plant was significantly increased in a quadratic with increasing concentrations of KNO3are optimum for growth of plant shoot weight were at 12.23 g in 100/of water on electrical conductivity equivalent to 2.01 dS.m-1. The addition of concentration of KNO3to nutrient solution does not affect on N and other nutrient solution on shoot tissue of lettuce plant but the concentrations of P and K in plant shoot tissue were significantly increased linearly with the provision of KNO3.

Recent advances on regiocentric homo-epitaxial approaches in bio-mimetically derived artificial non-wettable surfaces

Abstract Natural biosurfaces shows water repellence mainly because of its unique surface roughness and peculiar chemical compositions. Herein, we have mimicked the properties of the natural, non-wettable surfaces and created artificial water repellent surfaces using perpendicularly aligned zinc oxide (ZnO) nanostructured coatings having rough surface texture. These non-wettable surfaces were prepared through simple seed assisted hydrothermal methods. In the present method, a seed layer of nano regime zinc oxide was initially prepared on clean glass slides by coating and calcination methods. The as-synthesized seed layer was utilized for the hydrothermal growth of vertically oriented nanostructures. The structural and functional features of the resultant samples were studied using XRD, FTIR, UV-Vis. spectrophotometer and Contact angle analyzer. The homo-epitaxial growth and the crystallinity of ZnO nano particles were assessed using XRD. The structural studies were performed using FTIR and the optical transparency studies of the samples were carried out using UV–Vis. spectrophotometer. Along with the photographic image analyses, the water contact angle analyses were performed to predict the non-wettable character of the resultant coatings. At low nutrient solution concentrations (10 mM) and at low seed solution concentrations (1–10 mM), hydrophobic nanomaterials surfaces with high water contact angle, ˃130°, were successfully prepared through the present hydrothermal methods that extends many practical applications in biomedical, defense and industrial sectors.

Biofortification of calcium on mustard (Brassica juncea L.) and lettuce (Lactuca sativa) cultivated in floating hydroponic system

Calcium (Ca) is one of the essential macrominerals needed by the human body as a major component in the formation of bones and teeth. Calcium is fulfilled by eating calcium-rich foods, both animal and vegetable. Mustard and lettuce are vegetables that can be a source of Ca. Efforts to increase the Ca content in plants can be done through increasing the concentration of Ca given through fertilizer or in nutrient solution. However, excessive Ca application is not recommended because it will be toxic to plants. This study aims to determine the effect of various Ca concentrations in hydroponic nutrient solutions on the growth and yield of mustard vegetables (Brassica juncea L) and lettuce (Lactuca sativa L.). This study used a floating hydroponic system with a completely randomized design. Treatment of Ca concentrations of hydroponic nutrient solutions that were tried were 0, 100, 200, 300, and 400 ppm. The parameters observed were plant height, number of leaves, level of greenness of leaves, fresh and dry weight, and concentration of calcium in the leaves. The results showed that Ca treatment significantly affected the number of leaves and the level of leaf greenness. Application of 400 ppm Ca in hydroponic nutrient solution is the highest Ca concentration that could increase Ca content in mustard and lettuce plants. Application of Ca 300 ppm is the highest concentration of hydroponic nutrient solution that can increase the Ca content of plants without causing a decrease in plant biomass, and therefore the treatment of Ca 300 ppm can be used for biofortification of Ca by hydroponic in mustard and lettuce plants.

Effects of Photoperiod Interacted with Nutrient Solution Concentration on Nutritional Quality and Antioxidant and Mineral Content in Lettuce

The interacted effects of photoperiod and nutrient solution concentrations (NSCs) on nutritional quality and antioxidant and mineral content in lettuce were investigated in this study. There were a total of nine treatments by three photoperiods (12 h/12 h, 15 h/9 h, and 18 h/6 h), with a combination of three NSCs (1/4, 1/2, and 3/4 NSC). The contents of photosynthetic pigment, mineral element, and nutritional quality were markedly affected by the combination of photoperiod and NSC. The highest leaf number and plant weight were found in lettuce under the combination of 18–0.25X. There was a higher content of photosynthetic pigment in treatment of 15-0.25X. Shorter photoperiod (12 h/12 h and 15 h/9 h) and NSC (1/4 and 1/2 NSC) contributed to reduced nitrate contents and higher contents of free amino acid, soluble protein, and vitamin C. Longer photoperiod and lower NSC could increase soluble sugar content. The content of total P, K, and Ca exhibited a similar trend under the combination of photoperiod and NSC, with a higher content at 3/4 NSC under different photoperiods. Lower contents of total Zn and N were found under longer photoperiod. Moreover, higher antioxidant contents, including 2, 2-diphenyl-1-picrylhydrazyl (DPPH), value of ferric-reducing antioxidant power (FRAP), flavonoid, polyphenol, and anthocyanin were observed under shorter photoperiod, with the peak under 12-0.50X. Generally, 12-0.50X might be the optimal treatment for the improvement of the nutritional quality of lettuce in a plant factory that produced high-quality vegetables.

Effects of Concentration and Temperature of Nutrient Solution on Growth and Camptothecin Accumulation of Ophiorrhiza pumila.

The medicinal plant, Ophiorrhiza pumila, naturally grows on the floors of humid inland forests in subtropical areas. It accumulates camptothecin (CPT), which is used as an anti-tumor agent, in all organs. We investigated the optimal hydroponic root-zone environments for growth and CPT accumulation in O. pumila in a plant factory. In experiment 1, to determine the appropriate nutrient solution concentration (NSC), O. pumila was cultivated using four concentrations (0.125, 0.25, 0.5, and 1.0 times) of a commercial solution for 63 days after the start of treatment (DAT). The electrical conductivity of these NSCs was 0.6, 0.9, 1.5, and 2.7 dS m−1, respectively. The total dry weights at 0.25 and 0.5 NSCs were higher than those at the other two NSCs. CPT content at 0.25 NSC was significantly higher than those at other NSCs. In experiment 2, to investigate an appropriate nutrient solution temperature (NST), O. pumila was cultivated at four NSTs (10, 20, 26, and 35 °C, named as T10, T20, T26, and T36, respectively) for 35 DAT. The growth and CPT content at T20 was the highest among the treatments. Therefore, root-zone environments of 0.25 NSC and 20 °C of NST produced the best growth and CPT accumulation in O. pumila.

RESPUESTA DEL TOMATE DE CÁSCARA SILVESTRE MEXICANO (Physalis spp.) AL POTENCIAL OSMÓTICO EN HIDROPONÍA

El potencial osmótico (Ѱo) de las soluciones nutritivas puede influir en el crecimiento y la producción; sin embargo, el efecto está en función de la magnitud del Ѱo y de la demanda o capacidad de absorción de cada especie. El objetivo de la presente investigación fue determinar el crecimiento y rendmiento de tomate de cáscara silvestre mexicano (Physalis spp.) a diferentes potenciales osmóticos en la solución nutritiva. Se evaluaron los materiales 9b, 17b, 7b y Filadelfia con Ѱo de -0.018, -0.036 y -0.054 MPa bajo condiciones de invernadero e hidroponía. Se cuantificó el efecto de los tratamientos a los 30, 60 y 90 días después del trasplante (ddt) a través de mediciones de altura de planta, diámetro de tallo, número de flores por planta y lecturas de la intensidad del color verde de las hojas, o lecturas SPAD (Soil Plant Analysis Development). El porcentaje de flores caídas se determinó a los 90 ddt, y durante un mes se cuantificó el porcentaje de amarre de frutos, número de frutos por planta y peso de los frutos. En general, todas las variables fueron afectadas por el Ѱo de la solución nutritiva y por el material vegetal. La altura de planta, diámetro de tallo, número de flores y las lecturas SPAD fueron mayores conforme aumentó la concentración de la solución nutritiva (menor Ѱo); sin embargo, el porcentaje de flores caídas, amarre de frutos, número y peso de frutos fueon menores al exponer las plantas a -0.054 MPa. El material 9b alcanzó mayor altura y el 17b incrementó en mayor medida el diámetro con respecto a los otros materiales. Los genotipos 9b y 17b aumentaron el número de flores; 7b y 17b tuvieron el mayor porcentaje de flores caídas, 7b presentó las mayores lecturas SPAD y la mayor producción se consiguió con el material 9b. Todos los genotipos presentaron poco crecimiento con -0.018 MPa en la solución nutritiva y con un potencial osmótico elevado se redujo el rendimiento de frutos. El nivel intermedio (-0.036 MPa) es el potencial osmótico apropiado para la producción de frutos. La accesión 9b fue la más adecuada para la producción bajo invernadero porque mostró el mayor número de frutos y rendimiento.

Influence of nutrient solution concentration on growth and tissue mineral content of Panax ginseng seedlings cultured in a root medium containing peat and perlite

There is an increasing trend of producing seedlings of Panax ginseng in amended root media in raised beds. Precise control of the fertility of root media is essential for raising healthy seedlings, especially when inert media with a low buffering capacity are used. The objective of this study was to investigate the influence of fertility (as measured by EC) of the nutrient solution used for seedling production. One thousand eight hundred seeds were sown for five treatments and a control (300 seeds per treatment, 3 × 3 cm spacing) using root medium [composed of peat moss + perlite (7:3, v/v)] on raised beds with measurements, 120 × 60 × 25 cm (L × W × H) on Mar 9, 2018. Five nutrient solutions with different strengths (0.4, 0.6, 0.8, 1.0, 1.2 dS m−1 EC) were prepared with ground water (0.25 dS m−1) and a fertilizer stock solution (2 mM NH4+-N, 12 mM NO3−-N, 1 mM H2PO4−, 8 mM K+, 2 mM Ca2+, 1 mM Mg2+, 1 mM SO42−). Fertigation of the beds started on May 21 using each of six nutrient solutions and fertigation frequencies were controlled using an EC5 soil moisture sensor. The stock solutions were automatically supplied for 30 min when the volumetric water content decreased to 36%. Plant growth measurement and soil analyses were carried out twice: first at 144 days and subsequently at 197 days (from the day of seeds sown). For the first growth measurement, elevated EC in the fertilizer solution resulted in enhanced growth, but statistical differences among treatment solutions were not significant except for the case of ground water. In the second measurement, the seedling growth in terms of dry weight of above- and below-ground plant parts increased significantly in plants treated with the 1.0 dS m−1 EC solution and decreased in plants treated with the (1.2 dS m−1 EC) solution. In both the first and second measurements, the ground tissue nutrient content (T-N, P, K and Ca) was significantly different among treatments. The EC of root media in the case of 1.0 dS m−1 treatment, where the seedling growth was the highest among treatments, was 0.54 dS m−1 at the first measurement and 0.82 dS m−1 at the second measurement. In summary, a root medium with a mixture of peat moss + perlite (7:3, v/v), a leaching percentage of 20–30%, and a nutrient solution with a concentration of 1.0 dS m−1 EC is suitable for the healthy growth of ginseng seedlings.

Impact of Cu concentrations in nutrient solution on growth and physiological and biochemical parameters of beet and cabbage and human health risk assessment

Excess copper (Cu) in plant tissue may cause toxicity and pose a risk to human health. However, this is still not well known in the literature. The aim of this study was to evaluate the effect of Cu concentrations in nutrient solution on growth, physiological and biochemical parameters in beets and cabbages, in addition to human health risk assessment. Beets and cabbages were grown for 90 days in pots with sand and fertigated with nutrient solution containing five Cu concentrations (0.02, 0.27, 0.52, 0.77 and 1.02 mg L−1). Growth, physiological and biochemical parameters were evaluated in leaves, in addition to Cu contents and accumulation in organs of both species. We estimated the average portion intake of Cu (APICu) and the hazard quotient (HQ) associated with the consumption of beet tuberous root and cabbage head. Increasing Cu in solution reduced beet growth and increased Cu content and accumulation in organs of beet and cabbage, resulting in an increase in APICu and HQ. This highlights potential risks to human health, which are proportional to intake of in natura beet tuberous root and cabbage head.