Relations NO 3 - /anions and K + /cations in the nutrient solution for the growth of tomato seedlings

Parra-Terraza, Saúl; Parra-Terraza, Saúl

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Revista mexicana de ciencias agrícolas

versión impresa ISSN 2007-0934

Rev. Mex. Cienc. Agríc vol.7 no.7 Texcoco sep./nov. 2016

Articles

Relations NO ₃ ^- /anions and K ⁺ /cations in the nutrient solution for the growth of tomato seedlings

Saúl Parra-Terraza¹^§

¹Universidad Autónoma de Sinaloa- Facultad de Agronomía, Área de Suelos y Agua. Carretera Culiacán-El dorado km 17.5. A. P. 726. Culiacán, Sinaloa.

Abstract

In Sinaloa, tomato production in open field and in protected agriculture using seedlings produced in greenhouses. In the pre-transplant nutrition it is one of factors affecting growth and nutrient status of seedlings, so that the objective of this study was to evaluate the effect of three ratios NO3^-/ anions and three K⁺/ cations in the nutrient solution on growth, mineral composition and nutrient extraction tomato seedlings cv. 3832. The experimental design was completely randomized factorial arrangement of treatments 32 with four replications. At 40 days after planting, growth data were taken and the concentration of N, P, K, Ca and Mg in leaves and stems and nutrient extraction was determined. The NO3^-/anions x K⁺/cation interaction was significant for seedling height, stem diameter and dry weight and affected the concentrations and removals of N, P and K in stems. The relationship 80/100 NO₃ ^-/anions increase (p ≤ 0.05) dry weight, concentration and extraction of N and K in leaves, while the percentage ratio 55/100 K⁺/cations increased (p≤ 0.05) concentration and extracting sheet K and Mg reduced. In selecting tomato seedlings for transplantation should be considered the effect of NO₃ ^-/anions x K⁺/cation interaction on the variables height, diameter and dry weight of stem, the nutritional status of seedlings and environmental conditions of the area of production.

Keywords: Solanum lycopersicum L.; percentage ratio K⁺/cations; percentage ratio NO₃ ^-/anions; seedling growth

Resumen

En Sinaloa, la producción de tomate en campo abierto y en agricultura protegida utiliza plántulas que se producen en invernadero. En la etapa previa al trasplante la nutrición es uno de los factores que afectan el crecimiento y el estado nutrimental de las plántulas, por lo que el objetivo de este estudio fue evaluar el efecto de tres relaciones NO₃ ^-/aniones y tres de K⁺/cationes en la solución nutritiva, en el crecimiento, composición mineral y extracción nutrimental de plántulas de tomate cv. 3832. El diseño experimental fue completamente al azar con arreglo factorial de tratamientos 3² con cuatro repeticiones. A 40 días después de la siembra, se tomaron datos del crecimiento y se determinó la concentración de N, P, K, Ca y Mg en hojas y tallos y la extracción nutrimental. La interacción NO₃ ^-/aniones x K⁺/cationes fue significativa para altura de plántula, diámetro y peso seco de tallo y afectó las concentraciones y las extracciones de N, P y K en tallos. La relación 80/100NO₃ ^-/aniones aumento (p ≤ 0.05) el peso seco, las concentraciones y extracciones de N y K en hojas, mientras que la relación porcentual 55/100 K⁺/cationes incrementó (p ≤ 0.05) la concentración y extracción de K en hojas y redujo las de Mg. En la selección de plántulas de tomate para el trasplante se debe considerar el efecto de la interacción NO3^-/aniones x K⁺/cationes sobre las variables altura, diámetro y peso seco de tallo, el estado nutrimental de las plántulas y las condiciones ambientales del área de producción.

Palabras clave: Solanum lycopersicum L.; crecimiento de plántulas; relación porcentual NO3^-/aniones; relación porcentual K⁺/cationes

Introduction

In 2012, Mexico was the largest exporter of tomato worldwide with 23.6% of total exports, which generated foreign exchange earnings of1 553 million dollars. In that year, Sinaloa was the first producer of tomato with 21.8% of total production and income production value of 254 million dollars (^{SAGARPA, 2012}). In Sinaloa, the tomato is grown in open field and protected conditions of agriculture (greenhouse and shade house). In these production systems, uses tomato crop seedlings produced in greenhouses, and then are transplanted to the appropriate system.

The commercial production of tomato seedlings for transplanting in the open field or protected area is an activity that some sinaloenses greenhouses, at the request of the producers concerned, which provide seeds and pay a financial compensation to the producer, to take charge of cultural practices (planting in containers with soil, irrigation, fertilization, pest and disease control) until the seedlings are ready for transplanting.

In the pre-transplant nutrition it is one of the factors affecting growth and nutritional status of seedlings, which is closely related to earliness, yield and number of fruits per plant (^{Markovié et al., 1997}). Of the 17 nutrients recognized as essential to plants, usually the producer seedling applies a nutrient solution containing 12 nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Zn, Mn, B and Mo), as the C, H, O, Cl and Ni are not applied, because the first four plants get water or the air, while nickel does not apply because its impact on vegetables is unknown.

The N is a component of DNA, RNA, proteins, enzymes, chlorophyll, ATP, auxins and cytokinins (^{Hawkesford et al., 2012}), And can be supplied to plants in four ways: nitric, ammoniac, ureic and amino acids, although the nitrate form is preferentially absorbed by most crops (^{Mengel and Kirkby, 2000}), which is the most widely used in horticultural crops. However, to increase quality parameters of tomato seedlings, can be replaced 15% of the total N nitric in the nutrient solution, with a similar percentage of ammoniacal N and urea or a mixture 7.5% of N nitric plus 7.5% of ammonia nitrogen (^{Parra et al., 2010}).

The K is an essential macronutrient for plants; participates in the electric potential gradient in cell membranes, turgor, enzyme activation, photosynthesis, metabolism of sugars and starch, protein synthesis, the opening and closing of stomata, stabilization of cellular pH, and the cation-anion balance cell (^{Marschner, 1995}; ^{Mengel and Kirkby, 2000}). The NO3^- concentrations and K⁺ in the nutrient solution determines the ratio NO3^-/K⁺, better known as the N/K, which can be assessed by relative ratios ion, so a high concentration ofNO₃ ^-, regarding H₂PO₄ ^- and SO₄ ^2-, anions, and a low concentration of K⁺, compared to cations Ca²+ and Mg²+ in the nutrient solution, it indicates a high ratio NO₃ ^-/ K⁺. ^{Steiner (1961)} mentions that although many people consider important the relationship N/K, this importance is subject to discussion.

In Mexico, studies concerning the relationship N/K in the nutrient solution are scarce, using ratios NO3^-/anions and K⁺/cations on the growth of tomato, although commercially some general recommendations, based on total proportions N and K (^{Resh, 1992}). The objectives of this study were to determine the effect of three ratios NO₃ ^-/anions (NO₃ ^-, H₂PO₄ ^-and SO₄ ^2-) and three ratios K⁺/cations (K⁺, Ca²+ and Mg²+) in the nutrient solution on growth, mineral composition and extracting a nutritional tomato hybrid.

Materials and methods

From March 21 to April 30, 2013 an experiment was conducted in a greenhouse of the Faculty of Agronomy, located between 22° 30' and 27° 40' north latitude and 105° 24' and 109° 27'west longitude, at an altitude of 38 m and average temperature of 38/17 °C (day/night). The tomato seeds indeterminate growth cv. 3832 were sown in polystyrene trays of200 cavities with individual volume of 30 cm³; containing a mixture of peat and vermiculite (1:1 v/v).The experimental design was completely randomized factorial arrangement of treatments 3², and four repetitions, for a total of 32 experimental units, where each experimental unit consisted of 30 plants.

The factors and levels were evaluated: 1) percentage ratio NO3^-/anions (NO3^-, H₂PO₄ ^-, SO₄ ^2-) (40/100, 60/100 and 80/100); and 2) percentage ratio K⁺/cations (K⁺, Ca²⁺, Mg²⁺) (15/100, 35/100 and 55/100) (Table 1). By combining the three percentage ratios NO3^-/anions with three of K⁺/ cations are nine nutrient solutions (SN), which are designed from modifications of the universal SN (^{Steiner, 1984}) and consisted of varying the concentration of NO₃ ^- regarding H₂PO₄ ^- and SO₄ ^2-, and the concentration of K⁺ regarding a Ca²+ and Mg²+. The chemical composition of SN was calculated and adjusted to an osmotic potential of -0.072 MPa (Table 2), in accordance with proposed by ^{Steiner (1984)}.

Table 1 Relations between ions percentage of nutrient solutions used.

Table 2 Chemical composition of nutrient solutions used in the experiment.

The SN were prepared with inorganic salts reagent grade and distilled water and concentrations of micronutrients (mg L^-1) following were added: Fe 2.5, Mn 0.5, B 0.5, Cu 0.02 and Zn 0.05 (^{Parra et al., 2012}). The Fe provided as Fe-EDTA and the pH of the SN was adjusted 5.5 ± 0.1 with 1 N HCl or 1 N NaOH. Nine days after planting, when the seedlings had two true leaves, started the application of the SN, whose concentrations were increased 10 d in the order: 50, 75 and 100%. The plants were watered daily at 08:00 and 14:00 h spraying to foliage treatments atomizers (1 L capacity) until runoff from solution by the lower holes of the cavities. To avoid a possible accumulation of salts in the seedling foliage, from the SN to evaporate water, distilled water was sprayed by spray after each treatment application.

To evaluate the effect of the factors on the growth variables (height, stem diameter and dry weight of leaves, stems and seedlings) six plants were selected for treatment, and to determine the mineral composition of the stem 20 plants were chosen to 38 days after sowing, and four composite repetitions, each with five seedlings, whose branches fractionated on leaves and stems they were integrated. In these organs chemical analysis was performed to determine the concentration of N, P, K, Ca and Mg, according to methodologies proposed by ^{Motsara and Roy (2008)}. The variance analysis included the main factors and their interaction. Statistical analyzes were performed using SAS version 8 (^{SAS, 1999}).

Results and discussion

Growth variables

The analysis of variance showed significant effects (p≤ 0.05) of NO₃ ^-/anion interaction x K⁺/cations for seedling height (AP), stem diameter (DT) and stem dry weight (PST), while factor percentage ratio NO3^-/anions had statistical differences (p≤ 0.05) for leaf dry weight (PSH) and seedling dry weight (PSP) (Table 3). The AP obtained with three ratios NO3^-/anions were similar for relations 35 and 55/100 K⁺/cations, however, for the relationship 15/100 K⁺/cations ranged AP if (p≤ 0.05). The AP higher (26.7 and 27.5 cm) were obtained with the combinations 60 and 80/100 NO₃ ^-/anions with 15/100 K⁺/cations (Table 4), attributed to increases N in the SN increase growth (^{Fageria, 2001}). The AP is a basic indicator of the quality of seedling and according to ^{Lazic et al. (1993)}, the AP tomato at transplant must be between 20 and 30 cm. In this study all combinations NO₃ ^-/anions x K⁺/cations were suitable height values (22 to 27.5 cm).

Table 3 Effect of NO₃ ^-/anions and K⁺/cation ratio in the nutrient solution in height (AP), stem diameter (DT), dry weight of leaves (PSH), dry weight of stems (PST) and weight seedling dry (PSP) tomato.

Medias con las mismas letras en cada columna y cada factor, son estadísticamente iguales (Tukey, 0.05); ns= no significativo.

Table 4 Effect of NO₃ ^-/anion x K⁺/cation interaction in the nutrient solution on the height (AP), stem diameter (DT) and dry weight of stem (PST) of tomato seedlings.

Medias con las mismas letras en cada columna y cada factor, son estadísticamente iguales (Tukey, 0.05).

The diameters of stems (DT) obtained with the three ratios NO₃ ^-/anions were similar for the three ratios K⁺/cations (Table 4); however, analyzing the DT obtained with the three K⁺/cations relationships within each level of the ratio NO₃ ^-/anions, it was observed that the higher DT (3.24 mm) was obtained with the combination 40/100 NO3^-/anion and 55/100 K⁺/cations, while the less DT (2.52 mm) was obtained with 40/100NO₃ ^-/anion and 15/100 K⁺/cations, equivalent to a higher ratio N/K. the DT is a good indicator of seedling vigor, as it directly reflects the accumulation of photosynthates, which can move to demand sites (Preciado et al, 1992).

Furthermore, more DT prevents further flattens plants by wind in the field (^{Orzolek, 1991}), so the plantlets obtained with the combination 40/100 NO₃ ^-/anion and 15/100 K⁺/ cations have a lower quality and therefore less chance of success during transplantation, especially in areas with high wind conditions (Table 4). The PST obtained with the three ratios NO₃ ^-/anions were similar for relations 35 and 55/100 K⁺/cations. However, for the relationship 15/100 K⁺/cations ranged PST if (p≤ 0.05).

The greater PST (0.23 g) was obtained with the combination 80/100NO3^-/ anions x15/100 K⁺/cations, while the lowest (0.14 g) was obtained with 40/100NO₃ ^-/ anions x15/100 K⁺/cations; i.e., that increasing the N level 15/100 K⁺/ cations (higher ratio N/K) the PST significantly (p≤ 0.05). A higher dry matter content of the stems provides greater resistance to cold and less succulent to have lower water content are less brittle, so it is important to reduce stress after transplantation (^{Markovié et al., 1997}). The percentage ratio of NO₃ ^-/anions in the SN increased (p≤ 0.05) the PSH and the PSP, where the highest values (0.40 and 0.62 g) were obtained with the ratio 80/100 NO₃ ^-/ anions and lower values (0.33 and 0.50 g) were obtained with 40/100 NO₃ ^-/ anions (Table 3), a value that may not cover the demand for N of seedlings, reducing the PSH and PSP.

Nutrient concentration in leaves

The interaction NO₃ ^-/ anion x K⁺/cation was significant (p≤ 0.01) for the Ca concentration in leaves, while percentage ratio NO₃ ^-/anions factor in the SN affected the concentration of N, P and K, and ratio K/cations was different for N, K and Mg (Table 5). There was no effect on Ca concentrations obtained with the three NO3^-/anion ratio relationships for 55/100 K/cations, but there were differences for relations 15 and 35/100 K/cations. In these two ratios K/cations higher values (2.11 and 1.87% Ca) were obtained with 80/100 NO3^-/ anions, which were significantly higher concentrations of Ca obtained with 40 and 60/100 NO₃ ^-/anion (Figure 1).

Figure 1 Effect of NO₃ 7 anion x K⁺/cation interaction in the nutrient solution and the concentration of Ca in leaves of tomato cv. 3832. Points with different letters in a column and a line are statistically different (p≤ 0.05).

Table 5 Effect of NO₃ /anions and K⁺/cation ratio in the nutrient solution and the concentration of nutrients in leaves of tomato plants.

Medias con letras iguales en cada columna para cada factor, son estadísticamente iguales (Tukey, 0.05); ns= no significativo.

These results indicate that increasing the ratio N / K in the low and intermediate ratios K/cations (15 and 35/100), increased Ca absorption in the leaves (Figure 1), which can be attributed to lower concentrations K, as this nutriment when pre sent in high concentrations has a high mobility and reduces absorption of Ca (^{Fageria, 2001}; ^{Kavvadias et al., 2012}). The concentration of N in the leaves presented a linear trend with NO3^-/anions factor, because by increasing the percentage ratio NO₃ ^-/anions in the SN, the N concentrations in the leaves increased, and the highest concentration (4.93% of N) was obtained with 80/100 NO₃ ^-/anions and the lowest (4.42% N) was obtained with 40/100 NO3^- /anions (Table 5).

There was a negative trend between NO₃ ^-/anion ratio in the NS and P concentrations in leaves, because by increasing the ratio NO₃ ^-/anion concentrations P were significantly reduced (p≤ 0.05), so the highest value (0.81% of P) was obtained with 40/100 NO₃ ^-/anions and the lowest (0.45 of P) was obtained with 80/100 NO3^-/anions (Table 5). This reduction in the concentration of P, possibly arising from a dilution effect due to increased production of dry matter in the leaves, developed in the relationship 80/100 NO₃ ^-/anions (Table 3). In addition to this, the extraction of P by leaves from the relationship 80/100 NO₃ ^-/anions had the lowest value (1.85 mg plant^-1), which provides further evidence of the effect of dilution (Table 6).

Table 6 Effect of NO₃ ^-/ anions and K⁺/cation ratio in the nutrient solution and the concentration of nutrients in stems of tomato plants.

Medias con letras iguales en cada columna para cada factor, son estadísticamente iguales (Tukey, 0.05); ns = no significativo.

There was a tendency quadratic relationships NO3^-/anions and K concentrations, and that increasing 40/100to 60/100 of NO₃ ^-/anions in the SN concentrations K in leaves increased (p≤ 0.05); however, 80/100 NO₃/anions, the K concentration decreased, concerning at 40/100 NO3^-/anions (Table 5), possibly due to the dilution effect discussed above. The K concentrations increased linearly sheet (a higher concentration of K could increase (%) of K in the leaves), with K⁺/cations relations in the SN; the highest concentration (5.83%) was obtained 55/100 K⁺/cations and lower (3.67%) with 15/100 K⁺/cations. A negative trend was introduced between the K⁺/ cations and Mg concentrations in leaves, because the Mg concentrations decreased with increases in the K/cations, indicating antagonism between K and Mg (^{Fageria, 2001}), as the lower value (0.49% Mg) was obtained 55/100 K⁺/ cations and greater (0.88% Mg) was obtained with 15/100 K⁺/cations (Table 5). The K⁺/cation ratio affected (p≤ 0.05) the N concentration in leaves where the highest concentration (4.87%) was obtained with the ratio 15/100 K⁺/cations and the lowest (4.52%) with 35/100 K⁺/cations (Table 5).

Nutrient concentration stems

The interaction NO₃ ^-/anion x K⁺/cation was highly significant (p≤ 0.01) for concentrations of N, P, K and significant (p≤ 0.05) for Mg, while the ratio NO₃/anions was (p≤ 0.05) for the concentration of Ca (Table 6). The N concentrations obtained with three ratios NO3^-/anion ratio were equal to 55/100 K⁺/cations, but for relations 15 and 35/100 K/cations were differences (Table 7). For these two ratios K⁺/cations to increase NO₃ ^-/anion ratio in the nutrient solution, the concentrations of N had significant increases. The concentrations of P obtained with three ratios were different for the three relations K⁺/cations.

Table 7 Effect of NO₃ ^-/anions x K⁺/cations interaction in the nutrient solution in the concentration of nitrogen (N), phosphorus (P), potassium (K) and magnesium (Mg) in stems of tomato seedlings.

Medias con letras iguales en cada columna, son estadísticamente iguales (Tukey, 0.05).

For relations 15 and 35/100 K⁺/cations to increase relations NO3^-/ anion the P concentrations were reduced, and the lowest values (0.20 and 0.14% of P) were obtained with 80/100 NO₃ ^-/anions and 15 35/100 or K⁺/cations. In contrast, for the relationship 55/100 K⁺/cations, the highest concentration of P (0.43%) was obtained with 80/100 NO₃ ^-/ anions and the lowest (0.26% of P) with 40/100 NO₃ ^-/anions (Table 7). The K concentrations obtained with three ratios NO₃ ^-/anions were different (p≤ 0.01) for all three relations K/cations. For relations 15 35/100 K⁺/cations higher values (7.47 and 6.90% of K) was obtained with 60/100 MV/anions and by increasing the ratio 80/100 NO₃ ^-/anions in the SN, for both ratios K⁺/cations, K concentrations in the stems were reduced significantly (p≤ 0.01).

For the relation 55/100 K⁺/cations higher values (8.73 and 8.03% K) was obtained with 40 and 80/100 NO3^-/anions and the lowest value (6.37% of K) with 60/100 NO3^-/anion (Table 7). The Mg concentrations obtained with the three ratios NO₃ ^-/anions did not differ for the relationship 15/100 K⁺/cations; however, for relationships 30 and 45/100 K⁺/ cations if there were differences (p≤ 0.05). In these two ratios K⁺/cations the highest values (0.70 and 0.53% of Mg) were obtained with 80/100 NO₃ ^-/anions, while the lowest (0.40 and 0.28% of Mg) were obtained with 40/100 NO₃ ^-/anions and 30 or 45/100 K⁺/cations.

The interactions of N, P, K and Mg found in the present study coincides with ^{Fageria (2001)} who mentions that interactions of nutrients in plants are complex and can induce deficiencies, toxicities, modify crop response and alter the nutritional composition and that understanding these interactions is important in a balanced way to supply nutrients. The concentrations of Ca in stems were affected by the percentage ratio NO₃ ^-/anions in the SN where the highest value (0.84% Ca) was obtained with 80/100 NO₃ ^-/anions and the lowest (0.54% of Ca) it scored with 40 or 60/100 NO3^-/ anions (Table 6). This result agrees with that reported by other authors (^{Marschner, 1995}; ^{Mengel and Kirkby, 2000}) who mentioned that plants absorb nitrates preferentially contain high levels of cations, among which is calcium.

Nutrient uptake by leaves

The extractions of N, K and Ca were different for the percentage ratio NO₃ ^-/anions in the SN, where the largest withdrawals were achieved with 80/100 NO3^-/anions and minors were obtained with 40/100 NO3^-/anions. These results were due to increased dry weight of the leaves and at the highest concentrations of N, K and Ca in those plant organs. The percentage ratio K/cations affected statistically (p≤ 0.05) the extractions of K, Ca and Mg, where most extraction K (19.56 mg plant^-1) was achieved with 55/100 K⁺/cations and the lowest (13.46 mg plant^-1) with 15/100 K⁺/cations, however, the relationship 55/100 K⁺/cations significantly decreased extractions Ca and Mg, which is a reflection of K on antagonism uptake of Ca and Mg.

Nutrient uptake by stems

The interaction NO₃ ^-/anions x K/cations was significant for extractions of N, P and K. The extractions obtained with the three NO₃ ^-/anions were equal (p≥ 0.05) relations 35 and 55/100 K⁺/cations, although 15/100 K⁺/cations there were differences (p≤ 0.05), as most mining (11.09 mg plant¹) was obtained with 80/100 NO₃ ^-/anions and the lowest (5.42 mg plant^-1) with 40/100 NO₃ ^-/anions. The P extractions obtained with the three ratios NO₃ ^-/anions did not differ for relations 15 and 55/100 K⁺/cations, however for the relationship 35/100 K/cations if there were changes (p≤ 0.01), where higher values (1.21 and 1.21 mg plant^-1) were obtained with 40 and 60/100 NO3^-/anions and lower extraction (0.28 mg plant^-1) was obtained with 80/100 NO₃ ^-/anions.

Conclusions

The interaction between NO₃ ^-/anions and K⁺/cations in the nutrient solution affected (p≤ 0.05) the seedling height, diameter, dry weight and stem concentrations of N, P and K in the stem, so that the selection of tomato seedlings for transplanting in open field should be considered the effect of that interaction on these variables of growth, as well as the nutritional status of seedlings and environmental conditions (wind and temperature) of the production area.

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Received: March 2016; Accepted: June 2016

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