Fertilizer, preparation method thereof and application of fertilizer in improvement of tomato fruit quality

Abstract

The invention relates to the technical field of agricultural fertilizers, in particular to a fertilizer, a preparation method thereof and application of the fertilizer to improvement of tomato fruit quality. The fertilizer is prepared from 5 percent to 15 percent (v / v) of fish protein hydrolysate, 0.05 to 0.2 mmol / L of 1-aminocyclopropane-1-carboxylic acid and water. The preparation method of the fertilizer comprises the following steps: mixing the fish protein hydrolysate (the amino acid content is greater than or equal to 100g / L) with water in proportion, adding the ACC, stirring until the ACC is completely dissolved, sequentially adding the trace element compound and the seaweed extract, adding the environment-friendly surfactant, adjusting the pH value to 6.0-6.5, and uniformly mixing to obtain the fertilizer. The fertilizer provided by the invention can be used for improving the tomato fruit quality, and after the fertilizer is applied, the tomato yield can be increased by 15-25%, the fruit sugar degree can be increased by 25.87%, the vitamin C content can be increased by 20-30%, and the shelf life can be prolonged by 2-3 days. The fertilizer is completely prepared from biodegradable components, is free of chemical synthesis hormone residues and is environment-friendly.

Description

Technical Field

[0001] This invention relates to the field of agricultural fertilizer technology, and more specifically, to a fertilizer, its preparation method, and its application in improving the quality of tomato fruits. Background Technology

[0002] Tomatoes are an important economic crop widely cultivated globally, and the quality of their fruit directly impacts economic benefits. Currently, fertilizers on the market have the following problems:

[0003] (1) Long-term use of traditional chemical fertilizers leads to soil compaction and a decline in fruit quality;

[0004] (2) Although organic fertilizers (such as fish protein) are safe and environmentally friendly, their nutrients are released slowly and their active ingredients are easily fixed by the soil, resulting in an absorption efficiency of less than 30%.

[0005] (3) Single plant growth regulators have limited effects and pose a risk of overuse;

[0006] (4) There is a lack of comprehensive solutions to simultaneously improve fruit size, sugar content, vitamin content and storability;

[0007] (5) Lack of targeted components for regulating fruit quality.

[0008] In existing technologies, fish protein fertilizer and ACC are used separately in agricultural production, but there are no reports of their synergistic application. Summary of the Invention

[0009] This invention addresses the aforementioned problems by providing a fertilizer, its preparation method, and its application in improving tomato fruit quality. This invention solves the technical challenges through innovative formulation. Furthermore, ACC, as a direct precursor to ethylene synthesis, is conventionally understood to accelerate fruit ripening and softening at high concentrations of ethylene. Recent studies have shown that ACC may also function as a signaling molecule independent of ethylene. This invention achieves a breakthrough by discovering that at ultra-low concentrations of 0.05–0.2 mmol / L, ACC can activate the expression of amino acid transport proteins in tomato roots (such as SlAAP7) and form a synergistic signal with hydrophobic small peptides in fish protein hydrolysates, significantly improving the efficiency of directional nutrient transport to the fruit.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0011] In a first aspect, the present invention provides a fertilizer comprising 5% to 15% (v / v) fish protein hydrolysate, 0.05 to 0.2 mmol / L 1-aminocyclopropane-1-carboxylic acid, and water.

[0012] In the preferred embodiment, the amino acid content of the fish protein hydrolysate is ≥100g / L, and the fish protein hydrolysate contains more than 18 kinds of amino acids, small molecule peptides and biological polysaccharides.

[0013] In the preferred embodiment, the content of fish protein hydrolysate is 8% to 12% (v / v); the content of 1-aminocyclopropane-1-carboxylate is 0.08 to 0.15 mmol / L.

[0014] In a preferred embodiment, it further includes 0.5%–2.0% of a trace element complex, 1%–3% of seaweed extract, and 0.05%–0.2% of a surfactant; the trace element complex contains Zn, B, and Mo.

[0015] In the preferred embodiment, the trace element complex contains 0.1%–0.5% Zn, 0.3%–0.8% B, and 0.01%–0.1% Mo; the seaweed extract is selected from brown algae extract or green algae extract; and the surfactant is an alkyl polysaccharide.

[0016] A second aspect of the present invention provides a method for preparing the above-mentioned fertilizer, comprising the following steps:

[0017] S1. Mix fish protein hydrolysate and water in a certain proportion to obtain the first solution;

[0018] S2. Add 1-aminocyclopropane-1-carboxylic acid to the first solution, and after dissolution, obtain the second solution;

[0019] S3. Add the trace element complex and seaweed extract to the second solution in sequence to obtain the third solution;

[0020] S4. Add a surfactant to the third solution to obtain the fourth solution;

[0021] S5. Adjust the pH of the fourth solution to 6-6.5, mix well, and obtain the fertilizer.

[0022] A third aspect of the present invention provides an application of the above-mentioned fertilizer in improving the quality of tomato fruits.

[0023] Under the preferred embodiment, the application method for the above application is as follows:

[0024] (1) Application period: during the flowering period, young fruit stage and fruit enlargement period of tomatoes;

[0025] (2) Application method: foliar spraying or drip irrigation;

[0026] (3) Application concentration: dilute 800-1000 times for foliar spraying or 500-800 times for drip irrigation;

[0027] (4) Application frequency: once every 2 weeks, for a total of 3 to 4 times.

[0028] In the preferred embodiment, the tomato variety used in the above application is either Ailsa Craig or Micro Tom.

[0029] Under the preferred scheme, the tomato cultivation environment in the above application is as follows: daytime temperature 25-28℃, nighttime temperature 16-18℃, light duration 16h / d, light intensity 15000-20000 lux, and ambient humidity 60%-80%.

[0030] The beneficial effects of this invention are:

[0031] This invention innovatively combines fish protein hydrolysate with ACC (accumulated toxicity compound), and through their synergistic effect, improves fertilizer utilization efficiency by 25%–30% and reduces fertilizer dosage; significantly improves tomato fruit quality parameters (sugar content, vitamin C, appearance); extends post-harvest shelf life by 2–3 days, reducing losses; and is environmentally friendly with no harmful residues. The fertilizer formulation provided by this invention solves the technical bottleneck of traditional tomato fertilizers in quality improvement and has significant market application prospects. Attached Figure Description

[0032] Figure 1 This is a flowchart of the tomato cultivation process of the present invention;

[0033] Figure 2 This is a graph showing the effect of different fertilizer treatments on the weight of a single tomato fruit.

[0034] Figure 3 This is a graph showing the effect of different fertilizer treatments on the yield of a single tomato plant.

[0035] Figure 4 This is a graph showing the effect of different fertilizer treatments on the soluble solids content of tomato fruits.

[0036] Figure 5 This is a graph showing the effect of different fertilizer treatments on the vitamin C content of tomato fruits.

[0037] Figure 6 This is a graph showing the changes in fruit firmness after different fertilizer treatments and storage periods for tomatoes.

[0038] Figure 7 This shows the expression of the SlAAP7 gene in tomatoes obtained from different fertilizer treatments. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0040] In this invention, unless otherwise stated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Unless otherwise specified, the experimental methods in the embodiments are conventional methods. Where specific conditions are not specified in the embodiments, they should be performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0041] This invention discloses a fertilizer formula for improving the quality of tomato fruits. The fertilizer formula mainly consists of fish protein hydrolysate (FPH) and 1-aminocyclopropane-1-carboxylic acid (ACC), wherein the fish protein hydrolysate content is 5%–15% (v / v) and the ACC content is 0.05–0.2 mmol / L. This invention is the first to discover the synergistic effect of ACC and fish protein hydrolysate. By activating the ethylene signaling pathway in plants through ACC, it significantly improves the absorption and utilization rate of amino acids and trace elements from fish protein in tomatoes. This formula can simultaneously increase the single fruit weight, soluble solids content, vitamin C content, and fruit firmness of tomatoes, resulting in a 15%–25% increase in tomato yield, a 25.87% increase in fruit sugar content, a 20%–30% increase in vitamin C content, and a 2–3 day extension in shelf life. This fertilizer uses only biodegradable components, has no chemically synthesized hormone residues, and is environmentally friendly.

[0042] A fertilizer comprising the following components:

[0043] (a) Fish protein hydrolysate (FPH): 5%–15% (v / v);

[0044] (b) 1-Aminocyclopropane-1-carboxylic acid (ACC): 0.05–0.2 mmol / L;

[0045] (c) Water.

[0046] In the fertilizer of this invention, the fish protein hydrolysate is prepared from deep-sea fish through an enzymatic hydrolysis process, with an amino acid content ≥100g / L, containing more than 18 kinds of amino acids, small molecule peptides and biological polysaccharides, and is in aqueous formulation.

[0047] The preferred method for preparing fish protein hydrolysate includes the following steps:

[0048] Deep-sea fish (such as miscellaneous fish or processing by-products) are selected, impurities are removed, and the fish is cleaned and crushed into a fish paste. The fish paste is transferred to a reaction vessel, and proteases (such as papain or alkaline protease) are added. Hydrolysis is carried out for several hours at a suitable temperature (50–60°C) and pH value (adjusted according to enzyme characteristics, usually neutral or weakly alkaline) to break down large protein molecules into smaller peptides and amino acids. Inactivation and separation: The enzyme is inactivated by heating to above 85°C, terminating the reaction. The mixture is then centrifuged or filtered to separate the solid residue, obtaining a liquid hydrolysate. Concentration and drying: The hydrolysate is vacuum concentrated to remove some water, and then spray-dried to produce a powder; or it can be directly concentrated into a liquid finished product. Quality inspection and packaging: Nutritional components (peptide content, amino acid composition) and hygiene indicators are tested. After passing the tests, the product is packaged and stored.

[0049] The seaweed extract mainly uses brown algae (such as Laminaria japonica and kelp), with plant hormones >80ppm (total biostimulants), and is in aqueous formulation.

[0050] The preferred method for preparing seaweed extract includes the following steps:

[0051] Thoroughly wash to remove salt and impurities, then mechanically crush into small pieces or a slurry. Mix the seaweed fragments / slurry with a dilute alkaline solution (commonly 0.5%–2% KOH or K₂CO₃) and stir for several hours under gentle heating (60–80°C). The alkali breaks down cell walls, releasing active substances (hormones, polysaccharides, minerals, etc.). After extraction, neutralize to neutral or slightly acidic (pH 5.5–7.0) with an acid (such as phosphoric acid). Then filter or centrifuge to remove solid residue, obtaining a clear liquid extract. The liquid extract is concentrated at low temperature under vacuum to increase its concentration (to protect heat-sensitive components). Add an appropriate amount of preservative (such as potassium sorbate) to prevent spoilage.

[0052] Alkaline hydrolysis is a highly efficient and low-cost process and is the mainstream technology; low-temperature concentration and spray drying aim to retain bioactive components (biostimulants) to the maximum extent.

[0053] In the preferred embodiment, the fish protein hydrolysate content in the above fertilizer formula is preferably 8% to 12% (v / v); the ACC content is preferably 0.08 to 0.15 mmol / L.

[0054] In the preferred formulation, the fertilizer also includes auxiliary ingredients, as follows:

[0055] (d) Trace element complex: 0.5%–2.0%, the trace element complex contains Zn, B and Mo elements;

[0056] (e) Seaweed extract: 1%–3%;

[0057] (f) Surfactant: 0.05%–0.2%.

[0058] Furthermore, in the trace element complex, the Zn content is 0.1%–0.5%, the B content is 0.3%–0.8%, and the Mo content is 0.01%–0.1%; the seaweed extract is selected from brown algae extract or green algae extract, and contains natural auxins and cytokinins; the surfactant is an environmentally friendly surfactant, preferably an alkyl polysaccharide glycoside (APG).

[0059] In some preferred embodiments, the fertilizer formulation and the functions of each component of the present invention are shown in Table 1 below:

[0060] Table 1

[0061]

[0062]

[0063] This invention is the first to discover and apply the synergistic effect of fish protein hydrolysate and ACC, as detailed below:

[0064] 1. Synergistic mechanism: As an ethylene precursor, ACC activates the expression of amino acid transport proteins (such as SlAAP7) in tomato roots, significantly enhancing the absorption capacity of tomato roots and leaves of amino acids and trace elements from fish protein.

[0065] 2. Innovative formulation: The optimal ratio range of fish protein hydrolysate (5%–15%) to ACC (0.05–0.2 mmol / L) was determined through numerous experiments.

[0066] 3. Multiple quality enhancements: Simultaneously improves fruit weight, sugar content, nutritional value, and storage performance.

[0067] 4. Environmentally friendly: All components are biodegradable and contain no chemically synthesized hormone residues.

[0068] Unless otherwise specified, all percentage contents mentioned above are volume / volume percentages (v / v).

[0069] The preparation method of the above fertilizer includes the following steps:

[0070] (1) Mix fish protein hydrolysate with water in a certain proportion;

[0071] (2) Add ACC and stir until completely dissolved;

[0072] (3) Add the trace element complex and seaweed extract in sequence;

[0073] (4) Add surfactant;

[0074] (5) Adjust the pH to 6.0-6.5, mix well, and obtain fertilizer.

[0075] The application methods of the above fertilizers in improving tomato fruit quality are as follows:

[0076] Application period: during the flowering, young fruit, and fruit enlargement stages of tomatoes;

[0077] Application method: Apply evenly to the underside of the leaves by foliar spraying or by drip irrigation at a rate of 4-6 kg / mu;

[0078] Application concentration: dilute 800-1000 times for foliar spraying, and 500-800 times for drip irrigation;

[0079] Application frequency: once every 2 weeks, for a total of 3 to 4 times.

[0080] Using the above application method, the fertilizer provided by this invention was applied during the key growth period of tomatoes. Compared with fertilizers without added fish protein hydrolysate and ACC, the following effects were achieved, as shown in Table 2 below:

[0081] Table 2

[0082]

[0083] Furthermore, the tomato seed varieties to which the fertilizer provided by this invention is applicable include, but are not limited to, Ailsa Craig and Micro Tom.

[0084] Under the preferred scheme, the tomato cultivation environment is as follows: daytime temperature 25-28℃, nighttime temperature 16-18℃, photoperiod 16h / 8h, light intensity 15000-20000 lux, and ambient humidity 60%-80%.

[0085] Example 1: FPH+ACC (Optimal Formulation)

[0086] Fertilizer formula: 10% (v / v) fish protein hydrolysate (amino acid content ≥100g / L), 0.1mmol / LACC, 1% trace element complex (Zn:0.2%, B:0.3%, Mo:0.05%), 1.8% seaweed extract, 0.1% alkyl polysaccharide and water.

[0087] The method for preparing fertilizer includes the following steps:

[0088] According to the fertilizer formula provided in this embodiment, fish protein hydrolysate and water are mixed, ACC is added and stirred until completely dissolved, trace element complex and seaweed extract are added in sequence, then alkyl polysaccharide is added, pH is adjusted to 6.2, and after mixing evenly, fertilizer is obtained.

[0089] Comparative Example 1: No FPH+ACC (CK) added

[0090] Fertilizer formula: 1% micronutrient complex (Zn: 0.2%, B: 0.3%, Mo: 0.05%), 1.8% seaweed extract, 0.1% alkyl polysaccharide and water.

[0091] The method for preparing fertilizer includes the following steps:

[0092] According to the fertilizer formulation provided in this comparative example, add the trace element complex and seaweed extract to deionized water in sequence, then add alkyl polysaccharide glycoside, adjust the pH to 6.2, mix well, and the fertilizer is obtained.

[0093] Comparative Example 2: FPH alone

[0094] Fertilizer formula: 10% (v / v) fish protein hydrolysate (amino acid content ≥100g / L), 1% trace element complex (Zn:0.2%, B:0.3%, Mo:0.05%), 1.8% seaweed extract, 0.1% alkyl polysaccharide and water.

[0095] The method for preparing fertilizer includes the following steps:

[0096] According to the fertilizer formula provided in this comparative example, fish protein hydrolysate and deionized water are mixed and stirred until completely dissolved. Then, trace element complex and seaweed extract are added in sequence, followed by alkyl polysaccharide glycoside. The pH is adjusted to 6.2, and the mixture is stirred evenly to obtain the fertilizer.

[0097] Comparative Example 3: ACC alone

[0098] Fertilizer formulation: 0.1 mmol / L ACC, 1% micronutrient complex (Zn: 0.2%, B: 0.3%, Mo: 0.05%), 1.8% seaweed extract, 0.1% alkyl polysaccharide and water.

[0099] The method for preparing fertilizer includes the following steps:

[0100] According to the fertilizer formula provided in this comparative example, mix ACC and water and stir until completely dissolved. Then add the trace element complex and seaweed extract in sequence, followed by the alkyl polysaccharide glycoside. Adjust the pH to 6.2 and mix well to obtain the fertilizer.

[0101] Experimental example: Field trial

[0102] Ailsa Craig tomato plants with uniform growth and good quality were selected and randomly divided into four groups, with 10 plants in each group. The tomato plants were treated with fertilizers prepared in Example 1 and Comparative Examples 1-3. The cultivation environment for the tomato plants was as follows: daytime temperature 25-28℃, nighttime temperature 16-18℃, photoperiod of 16h light / 8h darkness, light intensity of 15000-20000 lux, and ambient humidity of 60%-80%. The fertilizer application method is as follows:

[0103] Application period: during the flowering, young fruit, and fruit enlargement stages of tomatoes;

[0104] Application method: Foliar spray;

[0105] Application concentration: Dilute 800-1000 times for foliar spraying;

[0106] Application frequency: once every 2 weeks, for a total of 3 to 4 times.

[0107] After the fruits matured, the weight of a single tomato and the yield per plant were recorded for each group. One tomato fruit was randomly picked from each tomato plant in each group, and the plants were grouped according to the different fertilizers applied. The soluble solids and vitamin C content of the tomato fruits were then measured.

[0108] Soluble solids determination in tomatoes: The soluble solids were determined using a PAL-BX / ACID 3 tomato sugar acidity meter (ATAGO, Japan). For each treatment, the pulp of ripe red tomatoes was taken, the juice was squeezed out, filtered through gauze, and dripped into the test area. The values ​​were recorded. Each fruit was tested three times.

[0109] The procedure for determining vitamin C content is as follows:

[0110] 1. Sample preparation: Mature tomato fruits were quick-frozen in liquid nitrogen, the stems and seeds were removed, and the pulp tissue was cut into pieces and mixed.

[0111] Extraction process: Weigh 5.0g of homogenized sample, add 20mL of pre-cooled extraction solution (containing 2% metaphosphoric acid-0.1% EDTA, pH 2.2), extract by sonication in an ice bath for 15min, centrifuge at 12000×g at 4℃ for 15min, take the supernatant and filter it through a 0.22μm filter membrane for later use.

[0112] 2. Chromatographic conditions

[0113] Instrument: Agilent 1260 HPLC system, equipped with a DAD detector.

[0114] Chromatographic column: ZORBAX SB-C18 column (4.6mm×250mm, 5μm), column temperature 30℃.

[0115] Mobile phase: 0.1% aqueous phosphoric acid solution (pH 2.5) - methanol (95:5, v / v), isocratic elution, flow rate 1.0 mL / min.

[0116] Detection wavelength: 245nm, injection volume: 20μL.

[0117] 3. Standard curve and quantification

[0118] Prepare gradient solutions of 0.1–100 μg / mL using L-ascorbic acid standard (Sigma-Aldrich) and inject the samples under the conditions described above.

[0119] Establish a peak area-concentration standard curve (R 2 ≥0.999), qualitative analysis was performed using retention time (approximately 3.8 min), and quantitative analysis was performed using the external standard method.

[0120] Tomato firmness determination: One tomato fruit was randomly picked from each tomato plant in each group, and the plants were grouped according to the different fertilizers applied. The fruits were stored in a normal temperature environment for 14 days, and the firmness of the tomato fruits was measured and recorded every two days. The results are shown in Table 3 and... Figures 2-6 As shown.

[0121] Table 3. Field trial results data

[0122] detection indicators Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Single fruit weight (g) 37.2±3 40.8±3 31.6±2 48.5±4 Yield per plant (kg) 0.644±0.01 0.816±0.02 0.632±0.01 0.97±0.04 Soluble solids (%) 7.2±0.3 8.2±0.2 7.0±0.3 9.0±0.4 Vitamin C (mg / 100g) 18.5±1.2 20.8±1.0 19.3±1.1 24.2±1.5 Shelf life (days) 10±1 11±1 11±1 13±1 Yield (g / plant) 0.644±0.01 0.816±0.02 0.632±0.01 0.97±0.04

[0123] The expression of SlAAP7 in tomato fruit was analyzed. The quantitative reaction system is shown in Table 4, and the reaction procedure is shown in Table 5.

[0124] Table 4 qRT-PCR reaction system

[0125]

[0126] Table 5. qRT-PCR reaction procedure

[0127]

[0128] This invention employs a synergistic effect of fish protein hydrolysate and ACC, with ACC activating the expression of amino acid transporters (such as SlAAP7) in tomato roots. This invention confirms through qRT-PCR and yeast heterologous expression experiments that SlAAP7 is significantly expressed in tomato roots and fruits, and its encoded protein has the ability to transport multiple amino acids such as Met and Asp. High expression of SlAAP7 can significantly improve the absorption and utilization rate of amino acids and trace elements from fish protein in tomatoes. The qRT-PCR experiment in this invention confirms that, compared with the CK, FPH, and ACC treatment groups, the application of FPH+ACC significantly increased the expression level of SlAAP7. This suggests that the improvement in fruit quality after the combination of FPH and ACC may depend on the activation of root amino acid transporter expression, thereby improving fruit quality. The specific method for qRT-PCR is as follows: tomato root samples are ground in liquid nitrogen, RNA is extracted, reverse transcribed into cDNA, and then detected by real-time quantitative fluorescence.

[0129] This invention employs a unique formulation design, using a specific ratio of ACC (0.05–0.2 mmol / L) combined with fish protein hydrolysate (5%–15%) to achieve optimal fertilizer efficacy while ensuring safety. Tomatoes treated with this fertilizer exhibit triple quality improvements: increased sugar content, soluble solids increased by 25.87%, vitamin C content increased by 20–30%, and fruit firmness extended shelf life by 2–3 days. The fertilizer formula of this invention uses only biodegradable components, contains no chemically synthesized hormone residues, and is environmentally friendly.

[0130] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A fertilizer, characterized in that, It includes 5%–15% (v / v) fish protein hydrolysate, 0.05–0.2 mmol / L 1-aminocyclopropane-1-carboxylic acid and water.

2. The fertilizer according to claim 1, characterized in that, The amino acid content of fish protein hydrolysate is ≥100g / L, and the fish protein hydrolysate contains more than 18 kinds of amino acids, small molecule peptides and biological polysaccharides.

3. The fertilizer according to claim 1, characterized in that, The content of fish protein hydrolysate is 8%–12% (v / v); the content of 1-aminocyclopropane-1-carboxylate is 0.08–0.15 mmol / L.

4. The fertilizer according to claim 1, characterized in that, It also includes 0.5%–2.0% trace element complex, 1%–3% seaweed extract and 0.05%–0.2% surfactant; the trace element complex contains Zn, B and Mo elements.

5. The fertilizer according to claim 1, characterized in that, The trace element complex contains 0.1%–0.5% Zn, 0.3%–0.8% B, and 0.01%–0.1% Mo; the seaweed extract is selected from brown algae extract or green algae extract; and the surfactant is an alkyl polysaccharide.

6. A method for preparing the fertilizer according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Mix fish protein hydrolysate and water in a certain proportion to obtain the first solution; S2. Add 1-aminocyclopropane-1-carboxylic acid to the first solution, and after dissolution, obtain the second solution; S3. Add the trace element complex and seaweed extract to the second solution in sequence to obtain the third solution; S4. Add a surfactant to the third solution to obtain the fourth solution; S5. Adjust the pH of the fourth solution to 6-6.5, mix well, and obtain the fertilizer.

7. The application of the fertilizer according to any one of claims 1 to 5 in improving the quality of tomato fruit.

8. The application according to claim 7, characterized in that, The application method is as follows: (1) Application period: during the flowering period, young fruit stage and fruit enlargement period of tomatoes; (2) Application method: foliar spraying or drip irrigation; (3) Application concentration: dilute 800-1000 times for foliar spraying or 500-800 times for drip irrigation; (4) Application frequency: once every 2 weeks, for a total of 3 to 4 times.

9. The application according to claim 7, characterized in that, The tomato varieties are Ailsa Craig or Micro Tom.

10. The application according to claim 7, characterized in that, The cultivation environment for tomatoes in the facility is as follows: daytime temperature 25-28℃, nighttime temperature 16-18℃, light duration 16h / d, light intensity 15000-20000 lux, and ambient humidity 60%-80%.

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