Evaluation of the Non-destructive Method Efficiency of Estimating Nitrogen Content in Jambu Plants Grown in Hydroponic System

Jambu is considered a leafy vegetable with expressive relevance in the regions that compose the Brazilian Amazon. However, there are challenges regarding its cultivation, particularly for the nutritional management, since there is little technical information that allows an increase in the efficiency of its production. In this sense, nitrogen (N) gains prominence, since it is related to the increased yield and quality of leafy vegetables, therefore its monitoring of N content in plants is necessary. The objective of this study was to evaluate the efficiency of using the SPAD index to estimate the N content of jambu leaves, total chlorophyll concentration, as well as its relationship with dry mass accumulation due to the increase of nitrogen concentration in the nutrient solution. The design used was completely randomized with eight replications. The treatments were six nitrogen concentrations in the nutrient solution (11, 13, 15, 17, 19 and 21 mmol L-¹). After 21 days of transplantation, the SPAD index was measured. Then, these plants were collected to quantify the total chlorophyll, dry mass and nitrogen content. In general, the variables were explained by increasing linear models. There was a positive correlation between the SPAD index and the other characteristics evaluated. Based on the results, the best response at the concentration of 21 mmol L-¹ in the nutrient solution stands out. In addition, the SPAD index has potential to be used in the diagnosis of nitrogen status in jambu leaves.

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Rocket plants in response to nitrogen concentration in nutrient solution

Horticultura Brasileira ◽

10.1590/s0102-0536-20210316 ◽

2021 ◽

Vol 39 (3) ◽

pp. 341-345

Author(s):

Paulo Henrique S Silva ◽

Arthur Bernardes Cecílio Filho ◽

Isaias dos S Reis ◽

Carolina S Nascimento ◽

Camila S Nascimento

Keyword(s):

Nutrient Solution ◽

Block Design ◽

Nitrogen Concentration ◽

Dry Mass ◽

Nitrate Content ◽

Hydroponic System ◽

N Concentration ◽

Randomized Block Design ◽

Number Of Leaves

ABSTRACT Nitrogen (N) is the second most accumulated nutrient in rocket. This nutrient greatly affects growth, productivity and quality of the vegetable. Rocket is the second most widely grown leafy vegetable in hydroponic system; however, no studies on how N concentration in nutrient solution affects this crop can be found in literature. We studied four concentrations (79.2; 118.8; 158.4 and 237.6 mg L-1 of N) in a randomized block design with five replicates. Maximum number of leaves, leaf area, dry mass and productivity of rocket cv. ‘Folha larga’ were obtained with the highest N concentration. The rocket quality, evaluated by the nitrate content, was maximum with 210.2 mg L-1 of N and its value in the concentration which maximized productivity is in the acceptable range for vegetables; so, it is recommended to grow rocket with 237.6 mg L-1 of N in the nutrient solution.

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Influence of Light Regime and Leaf Nitrogen Concentration on 77k Fluorescence in Leaves of Four Tropical Grasses: No Evidence for Photoinhibition

Functional Plant Biology ◽

10.1071/pp9880669 ◽

1988 ◽

Vol 15 (5) ◽

pp. 669 ◽

Cited By ~ 8

Author(s):

MM Ludlow ◽

SP Samarakoon ◽

JR Wilson

Keyword(s):

Nitrogen Content ◽

Nitrogen Availability ◽

Nitrogen Concentration ◽

Chlorophyll Concentration ◽

Leaf Nitrogen ◽

Nitrogen Supply ◽

Poor Growth ◽

Full Sunlight ◽

Nitrogen Treatments ◽

Low Nitrogen

This work was undertaken to determine if the stimulation of growth associated with shading of some tropical C4 grasses growing on soils with low to moderate nitrogen availability is partly due to overcoming photoinhibition (i. e. damage caused by excessive light). Four grasses (green panic, carpet grass, buffalo grass and kikuyu) were grown in full sunlight and at 37% of full sunlight, and given a low or high nitrogen supply. Despite differences of up to twofold in leaf nitrogen and chlorophyll concentration between high and low nitrogen treatments in all four grasses, photoinhibition measured by reduction in chlorophyll fluorescence was less than 3% in leaves of low nitrogen content that developed in full sunlight. Therefore, photoinhibition is not a contributor to the poor growth of nitrogen-limited grasses in full sunlight. A second objective was to determine if low nitrogen content predisposed shade-grown leaves to photoinhibition when they were subsequently exposed to full sunlight. Green panic plants that had been given either high or low nitrogen supply and grown in 37% of full sunlight were transferred to full sunlight and the extent of photoinhibition was followed over 8 days. The amount of photoinhibition that occurred was small (<6%) compared with plants grown at either nitrogen level in full sunlight. Therefore, shade and low nitrogen content separately or in combination did not cause any appreciable photoinhibition in green panic.

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Nitrogen levels in the cultivation of strawberries in soilless culture

Horticultura Brasileira ◽

10.1590/s0102-05362011000400012 ◽

2011 ◽

Vol 29 (4) ◽

pp. 516-519 ◽

Cited By ~ 5

Author(s):

Jerônimo L Andriolo ◽

Lígia Erpen ◽

Francieli L Cardoso ◽

Carine Cocco ◽

Gustavo S Casagrande ◽

...

Keyword(s):

Plant Growth ◽

Nutrient Solution ◽

Nitrogen Concentration ◽

Fruit Size ◽

Dry Mass ◽

Fruit Yield ◽

Nitrogen Levels ◽

Crown Diameter ◽

Yield And Quality ◽

Number Of Leaves

In soilless grown strawberry crops, the nitrogen concentration of the nutrient solution affects plant growth and fruit yield and quality. The present research was conducted to determine the effect of nitrogen concentration in the nutrient solution on plant growth and development and fruit yield and quality of this crop. Treatments consisted of five nutrient solutions at nitrogen concentrations of 6.5 (T1), 8.0 (T2), 9.5 (T3), 11.0 (T4) and 12.5 (T5) mmol L-1, in an entirely randomised experimental design with four replications. Ripe fruit yield was determined during the harvest period from June 6th to November 27th, 2009. Number of leaves, shoot and root dry mass and crown diameter were determined at the later date. Number of leaves, shoot and root dry mass and crown diameter decreased by effect of increasing N concentrations in the nutrient solution. Fruit yield and fruit size fitted a polynomial model, with maximum values at 8.9 mmol N L-1. The N concentration used for the strawberry crop in soilless growing systems can be reduced to 8.9 mmol L-1 without any reduction in fruit yield.

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Producing Nitrate-free Endive Heads: Effect of Nitrogen Form on Growth, Yield, and Ion Composition of Endive

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.122.1.140 ◽

1997 ◽

Vol 122 (1) ◽

pp. 140-145 ◽

Cited By ~ 38

Author(s):

Pietro Santamaria ◽

Antonio Elia

Keyword(s):

Growth Rate ◽

Nutrient Solution ◽

Value Added ◽

Dry Mass ◽

Leafy Vegetables ◽

Fresh Mass ◽

Nitrate Content ◽

The European Union ◽

N Accumulation ◽

Total N

In a growth chamber, endive (Cichorium endivia L. var. crispum Hegi) plants were grown using a solution culture method to evaluate the influence of four ammonium : nitrate (NH4-N : NO3-N) percentage ratios (100:0, 70:30, 30:70, and 0:100) on growth (leaf area, dry mass, crop growth rate, relative growth rate, and net assimilation rate), yield characteristics (head and root fresh mass and root length), quality (dry matter, nitrogen, and nitrate), and inorganic ion content. No symptoms of NH4+ toxicity were detected in endive plants 8 weeks after beginning nutrient treatments. Moreover, by feeding N in mixed form, the growth indices increased compared to indices from feeding with any of the two N forms alone. Ammonium-fed plants produced nitrate-free heads with a fresh mass (171 g) similar to nitrate-fed plants. Compared to the other treatments, the heads of NH4+-fed plants were darker green and more succulent. Mixed N improved yield but caused a remarkable accumulation of nitrate in heads. Following an increase in NO3-N from 30% to 70% in the nutrient solution, head fresh mass rose from 196 to 231 g and NO3- concentration more than doubled (from 2.4 to 6.1 g·kg-1 fresh mass). With 100% of NO3-N, NO3- concentration was 5.5 g·kg-1 fresh mass. With higher NO3-N percentages in the nutrient solution, the difference in the concentration of inorganic cations and anions increased, but K+ concentration was also high in ammonium-fed plants (on average 77 g·kg-1 dry mass). Head total N accumulation was increased by the presence of NH4+ in the nutrient solution and decreased with 100% NO3-N. From the commercial viewpoint, the produce obtained from 100% NH4-N was good, with the value-added factor of the absence of nitrate. This may be an extremely remarkable factor because of the commercial limits on the allowable nitrate content in leafy vegetables already enforced by many European countries and those the European Union is going to adopt in a directive.

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Nutritional Efficiency and Morphophysiological Aspects With Growth in the ‘Okinawa Roxo’ Peach Rootstock

Journal of Agricultural Science ◽

10.5539/jas.v11n9p221 ◽

2019 ◽

Vol 11 (9) ◽

pp. 221

Author(s):

Aline das G. Souza ◽

Cristina W. Ritterbusch ◽

Renata D. Menegatti ◽

Oscar J. Smiderle ◽

Valmor J. Bianchi

Keyword(s):

Chlorophyll Content ◽

Nutrient Solution ◽

Nitrogen Concentration ◽

Zinc Content ◽

Dry Weight ◽

Total Chlorophyll ◽

Peach Tree ◽

Shoot Dry Weight ◽

Accurate Indication ◽

Nutrient Solutions

The aim of this study was to evaluate the efficiency of nutrient uptake, accumulation, distribution and use, and its relationship with growth variables, chlorophyll content, and root and shoot dry-weight partitioning in the ‘Okinawa Roxo’ peach rootstock, submitted to different nutrient solutions and substrates. The experimental design was completely randomised, with four treatments and five replications. The treatments were T1: Ns1 = Souza et al. nutrient solution (2011), applied to a sand substrate; T2: Ns2 = Hoagland and Arnon (1950), applied to a sand substrate; T3: Commercial Substrate + H2O; and T4: Control, Sand + H2O. Ninety days after transplanting (DAT), morphological, physiological and nutritional parameters were determined in the ‘Okinawa Roxo’ rootstock, together with the correlation between nitrogen concentration and nitrogen balance index, and the chlorophyll content and index. The greatest zinc content was detected in the shoots of the ‘Okinawa Roxo’ plants, at more than 80% of the accumulated total. Treatments T1 and T2 (nutrient solutions Ns1 and Ns2 respectively) made it possible to obtain ‘Okinawa Roxo’ plants with the best morphophysiological characteristics, being ready for grafting three months after transplanting in a greenhouse. The use of the Ns1 nutrient solution resulted in greater efficiency in the uptake and use of the nutrients nitrogen (N), potassium (K) and iron (Fe). The N and Total Chlorophyll concentrations in the leaves of the red-leaved peach tree can be estimated indirectly with a chlorophyll meter, and are an accurate indication of the nutritional status of the plant in relation to nitrogen content.

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NITROGEN NUTRITION OF CITRUS NURSERY STOCK IN PINE BARK SUBSTRATES.

HortScience ◽

10.21273/hortsci.25.9.1161f ◽

1990 ◽

Vol 25 (9) ◽

pp. 1161f-1161

Author(s):

John D. Lea-Cox ◽

Irwin E. Smith

Keyword(s):

Nutrient Solution ◽

Nitrogen Nutrition ◽

Dry Mass ◽

Pine Bark ◽

Growing Period ◽

Rough Lemon ◽

Nursery Stock ◽

Citrus Rootstock ◽

Cleopatra Mandarin ◽

Nutrient Solutions

Pine bark is utilized as a substrate in citrus nurseries in South Africa. The Nitrogen (N) content of pine bark is inherently low, and due to the volubility of N, must be supplied on a continual basis to ensure optimum growth rates of young citrus nursery stock. Three citrus rootstock (rough lemon, carrizo citrange and cleopatra mandarin) showed no difference in stem diameter or total dry mass (TDM) when supplied N at concentrations between 25 and 200 mg ·l-1 N in the nutrient solution over a 12 month growing period. Free leaf arginine increased when N was supplied at 400 mg·l-1 N. The form of N affected the growth of rough lemon. High NH4-N:NO3-N (75:25) ratios decreased TDM when Sulfur (S) was absent from the nutrient solution, but not if S was present. Free arginine increased in leaves at high NH4-N (No S) ratios, but not at high NH4-N (S supplied) ratios. Free leaf arginine was correlated with free leaf ammonia. These results have important implications for reducing the concentration of N in nutrient solutions used in citrus nurseries and may indicate that higher NH4-N ratios can be used when adequate S is also supplied.

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Nutrient Solution Deprivation as a Tool to Improve Hydroponics Sustainability: Yield, Physiological, and Qualitative Response of Lettuce

Agronomy ◽

10.3390/agronomy11081469 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1469

Author(s):

Michele Ciriello ◽

Luigi Formisano ◽

Antonio Pannico ◽

Christophe El-Nakhel ◽

Giancarlo Fascella ◽

...

Keyword(s):

Nutrient Solution ◽

Potential Effect ◽

Quality Parameters ◽

Leafy Vegetables ◽

Nitrate Content ◽

Yield Reduction ◽

Quality Performance ◽

Floating Raft ◽

Amino Acids Profile ◽

Excessive Nutrients

Hydroponics growing systems often contain excessive nutrients (especially nitrates), which could lead to a quality loss in ready-to-eat leafy vegetables and posing a health risk to consumers, if managed inadequately. A floating raft system was adopted to assay the production and quality performance of lettuce (Lactuca sativa L. cv ‘Maravilla De Verano Canasta’) deprived of the nutrient solution by replacement with only water, three and six days before harvest. Yield and quality parameters, mineral composition, pigments, organic acids, amino acids profile, soluble proteins, and carbohydrate content were determined. Nutrient solution deprivation six days before harvest resulted in a significant reduction in leaf nitrate (−53.3%) concomitant with 13.8% of yield loss, while plants deprived of nutrient solution three days before harvest increased total phenols content (32.5%) and total ascorbic acid (102.1%), antioxidant activity (82.7%), anthocyanins (7.9%), sucrose (38.9%), starch (19.5%), and γ-aminobutyric acid (GABA; 28.2%), with a yield reduction of 4.7%, compared to the control. Our results suggest that nutrient solution deprivation three days before harvest is a successful strategy to reduce nitrate content and increase the nutritional quality of lettuce grown in floating raft systems with negligible impact on yield. These promising results warrant further investigation of the potential effect of nutrient solution deprivation on the quality attributes of other leafy vegetables cultivated in floating raft systems and in a “cascade” growing system.

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Nitrogen for growth of stock plants and production of strawberry runner tips

Bragantia ◽

10.1590/s0006-87052012005000027 ◽

2012 ◽

Vol 71 (3) ◽

pp. 394-399 ◽

Cited By ~ 3

Author(s):

Djeimi Isabel Janisch ◽

Jerônimo Luiz Andriolo ◽

Vinícius Toso ◽

Kamila Gabriele Ferreira dos Santos ◽

Jéssica Maronez de Souza

Keyword(s):

Leaf Area ◽

Nutrient Solution ◽

Dry Matter ◽

Nitrogen Concentration ◽

Growth Period ◽

Dry Matter Partitioning ◽

Area Index ◽

Camino Real ◽

Nitrogen Concentrations ◽

Crown Roots

The objective of this research was to determine growth and dry matter partitioning among organs of strawberry stock plants under five Nitrogen concentrations in the nutrient solution and its effects on emission and growth of runner tips. The experiment was carried out under greenhouse conditions, from September 2010 to March 2011, in a soilless system with Oso Grande and Camino Real cultivars. Nitrogen concentrations of 5.12, 7.6, 10.12 (control), 12.62 and 15.12 mmol L-1 in the nutrient solution were studied in a 5x2 factorial randomised experimental design. All runner tips bearing at least one expanded leaf (patent requested) were collected weekly and counted during the growth period. The number of leaves, dry matter (DM) of leaves, crown and root, specific leaf area and leaf area index (LAI) was determined at the final harvest. Increasing N concentration in the nutrient solution from 5.12 to 15.12 mmol L-1 reduces growth of crown, roots and LAI of strawberry stock plants but did not affect emission and growth of runner tips. It was concluded that for the commercial production of plug plants the optimal nitrogen concentration in the nutrient solution should be 5.12 mmol L-1.

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Effect of heavy metals on the leaf disc ferricyanide reduction in cucumber

Acta Agronomica Hungarica ◽

10.1556/aagr.57.2009.3.6 ◽

2009 ◽

Vol 57 (3) ◽

pp. 307-320

Author(s):

G. Rabnecz ◽

G. Záray ◽

L. Lévai ◽

F. Fodor

Keyword(s):

Heavy Metals ◽

Nutrient Solution ◽

Chlorophyll Concentration ◽

Leaf Disc ◽

Transport Systems ◽

Ferricyanide Reduction ◽

Plasma Membrane Electron Transport ◽

Significant Linear Correlation ◽

Drastic Effect

The effect of heavy metals on the leaf plasma membrane electron transport systems was investigated in connection with the tissue Fe concentration in Fe-sufficient and Fe-deficient cucumber leaves. Ten M μPb in the nutrient solution inhibited leaf ferricyanide reduction by 20–26%, whereas 10 M μCd had a more drastic effect, with 80–83% inhibition. Ferricyanide reduction decreased by 14% when 1 mM Pb was applied in situ by vacuum infiltration into control leaf discs, whereas it decreased by 40% when 0.1 mM Cd was applied. Ferricyanide reduction was completely inhibited by 1 mM Cd. The ferricyanide reduction values were correlated with the heavy metal, Fe and chlorophyll concentrations in the leaves. A significant linear correlation was only found with the chlorophyll concentration. The data suggest that there are also direct effects on membranebound reductases, but these are of less significance. Using differentially Fe-deficient plants (grown with 0 to 300 nM Fe in the nutrient solution), a chlorophyll concentration of 0.9–1.0 mg g −1 fresh weight was estimated as the threshold for achieving the ferricyanide reduction levels found in the controls.

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