A betaine-containing fertilizer for reducing split fruit and preventing early spring cold

Abstract

The application discloses a betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold, and belongs to the technical field of fertilizers.The fertilizer is prepared according to the following steps: preparing an anti-caking agent, preparing a composite betaine, and mixing.The anti-caking agent is prepared by mixing silicon dioxide and water, stirring at room temperature, adding cetyltrimethylammonium bromide, stirring, adding sodium dodecyl sulfate, stirring, centrifuging, taking the precipitate, and drying.The mixture is prepared by uniformly mixing betaine, betaine phosphate, free amino acid, inorganic calcium, EDTA chelated calcium, a boron source, the anti-caking agent, and the composite betaine, and drying.The fertilizer has good effects of reducing fruit cracking and preventing early spring cold, has strong anti-caking capacity, and still has excellent anti-caking capacity at a high storage temperature, does not need to be granulated and coated during preparation, has small requirements on raw materials, and does not cause precipitation after being dissolved.

Description

Technical Field

[0001] This invention relates to the field of fertilizer technology, specifically to a betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost. Background Technology

[0002] Fruit cracking before maturity has always been a key issue affecting fruit quality and economic benefits. Cracking occurs when fruit is nearing maturity, and prolonged drought followed by rain or sudden irrigation causes the peel to rupture due to increased turgor pressure from water absorption or uneven growth rates between the pulp and peel. Cracking makes the fruit prone to rotting and spoilage, rendering it unmarketable and causing significant economic losses for producers. Related research indicates that three factors—turgor pressure, peel mechanical strength, and peel extensibility—jointly regulate fruit cracking. Turgor pressure is influenced by water, gibberellin, and abscisic acid content; peel mechanical strength is affected by calcium and cell wall components; and peel extensibility is influenced by cell wall relaxation genes.

[0003] In recent years, late frost damage has been particularly severe in northern my country. Some fruit trees that flower early in spring frequently suffer from late frost damage, resulting in reduced yields or even total crop failure. There are various types of frost, categorized by the season: spring frost, autumn frost, and winter frost. Spring frost (commonly known as "late spring cold snap") is the most damaging to fruit trees because they are often in their flowering or young fruit stages, making their organs less resistant to low temperatures. Related research indicates that frost-induced flower and fruit drop is primarily caused by damage to the cell membranes of flowers and young fruits. Reactive oxygen species (ROS), including hydroxyl radicals, singlet radicals, and H2O2, work with lipoxygenases to initiate membrane peroxidation. Normal plant cells possess enzymatic and non-enzymatic antioxidant defense systems that keep ROS within a certain range, preventing external attacks on the cell membrane. When plants encounter low-temperature stress, reactive oxygen species accumulate rapidly, their ability to scavenge reactive oxygen species decreases, membrane lipid peroxidation intensifies, membrane permeability increases, and a large amount of intracellular contents are lost, leading to cell death and resulting in excessive flower and fruit drop.

[0004] One of the most common methods for addressing fruit cracking and late spring frost problems is fertilizer treatment. The effects of exogenous gibberellin and amino acid calcium treatment on fruit cracking in 'Tomorrow' citrus, published by Dai Lin et al. in *Chinese Agricultural Science Bulletin*, March 2024, showed that changes in the content of different types of pectin in the peel are the main factor in fruit cracking in 'Tomorrow', and that exogenous application of gibberellin and amino acid calcium can significantly reduce the cracking rate. A preliminary report on the prevention of sweet cherry fruit cracking by exogenous betaine, published by Zhang Xu et al. in *Yantai Fruit Trees*, January 2014, stated that betaine is one of the most common and important osmotic regulators in higher plants. It can act as a non-toxic osmotic substance in plants, participating in cellular osmotic regulation, maintaining water balance and cell swelling pressure, and protecting the activity of intracellular proteins and metabolic enzymes. Foliar spraying of betaine on sweet cherries helps maintain fruit cell swelling pressure, thereby reducing the occurrence of fruit cracking. The Effects of Frost Damage on 'Chun Jian' Citrus Fruit and the Effect of Greenhouse Frost Protection. Zhou Jie. Master's Thesis, Sichuan Agricultural University. June 2023. Osmotic regulators are one of the important regulatory pathways for plants to enhance their cold resistance in response to low-temperature stress. The content of intracellular osmotic regulators is closely related to the cold resistance of plants. Low-temperature stimulation can induce plant cells to produce osmotic regulators such as proline, soluble proteins, and soluble sugars, thereby improving the cold resistance of plants. Osmotic regulators include betaine. Fruit Cracking Mechanism and Prevention Measures in Plum. Zhang Linjing et al. Journal of Horticulture. August 2006. Spraying borax solution can significantly reduce fruit cracking in Sui Li No. 3. It also disclosed that boron is required for the structural functions of plant cell walls, such as cell wall synthesis, cell wall lignification, transmembrane transport of cell wall structures, and membrane integrity.

[0005] In summary, betaine, free amino acids, calcium, and boron can be used to reduce fruit cracking and prevent late spring frosts, respectively. Furthermore, the applicant discovered that betaine phosphate, when applied in agriculture, can supplement phosphorus and improve plant growth performance. Therefore, in preparing fertilizers to reduce fruit cracking and prevent late spring frosts, the applicant added betaine phosphate, free amino acids, calcium sources, and boron sources to the produced betaine, hoping to obtain a compound water-soluble fertilizer with excellent overall effects. The free amino acid used was glycine, the calcium source was calcium chloride, calcium nitrate, or EDTA chelated calcium, and the boron source was borax. However, after adding betaine phosphate, free amino acids, calcium sources, and boron sources to the produced betaine, the applicant used physical stirring to obtain a powdered compound water-soluble fertilizer, which easily clumps during storage.

[0006] Analysis revealed that the main cause of caking is the strong hydrophilicity of compound water-soluble fertilizers. Regarding the caking problem, based on research progress on surfactants for anti-caking agents in water-soluble fertilizers (Dong Xizhe et al., *China Petroleum and Chemical Standards and Quality*, April 2017) and analysis of influencing factors on caking of medium-element (calcium) water-soluble fertilizers (Wang Hongfu et al., *Phosphate Fertilizers and Compound Fertilizers*, December 2020), the most common methods currently used are adding surfactants to compound water-soluble fertilizers, adding inert powders to compound water-soluble fertilizers, and increasing the particle size of compound water-soluble fertilizers. Regarding the addition of surfactants to compound water-soluble fertilizers, based on research on anti-caking agents for water-soluble powdered compound fertilizers (Huo Xiaoyue, *Master's Thesis, Yanshan University*, May 2016), surfactants need to be combined with granulation or coating, and their anti-caking ability is poor at high storage temperatures. Adding inert powders to compound water-soluble fertilizers, commonly used inert powders include clay, kaolin, talc, silica, and diatomaceous earth. Inert powders can mechanically isolate the compound water-soluble fertilizer to a certain extent or prevent it from absorbing moisture from the air, thus reducing the tendency for the fertilizer to clump. However, inert powders are insoluble in water, causing the prepared compound water-soluble fertilizer to easily precipitate after dissolving, which can also affect the plant's nutrient absorption process. Increasing the particle size of compound water-soluble fertilizers increases the requirements for raw materials. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost. The fertilizer of this invention has good effects in reducing fruit cracking and preventing late spring frost, strong anti-caking ability, and still has excellent anti-caking ability at high storage temperatures. It does not require granulation or coating in preparation, has low requirements for raw materials, and does not precipitate after dissolution.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0009] A betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost is prepared according to the following steps: preparing an anti-caking agent, preparing compound betaine, and mixing them;

[0010] To prepare the anti-caking agent, silica and water are mixed and stirred at 100-300 rpm at room temperature for 30-50 minutes. Then, hexadecyltrimethylammonium bromide is added and stirred for another 30-50 minutes. Sodium dodecyl sulfate is added and stirred for another 60-80 minutes. The mixture is then centrifuged at 5000-6000 rpm for 10-15 minutes. The precipitate is collected, dried, and the anti-caking agent is obtained.

[0011] In the preparation of the anti-caking agent, the mass ratio of silicon dioxide, water, hexadecyltrimethylammonium bromide, and sodium dodecyl sulfate is 100:1000-1200:0.1-0.11:0.23-0.25.

[0012] The silica has a particle size of 2 μm;

[0013] To prepare the composite betaine, a calcium hydroxide suspension was stirred at 100-300 rpm at room temperature, followed by the dropwise addition of an aqueous chloroacetic acid solution. After the addition was complete, the mixture was filtered, and the filtrate was collected. The filtrate was then stirred at 100-300 rpm at room temperature, followed by the dropwise addition of an aqueous trimethylamine solution. After the addition was complete, the mixture was stirred for 30-40 minutes, heated to 50-60°C, stirred for 70-90 minutes, heated to 70-80°C, stirred for 70-90 minutes, cooled to room temperature, and polyethylene glycol 2000 and sodium dodecyl sulfate were added. The mixture was stirred for 30-40 minutes, concentrated, vacuum dried, and ground to obtain the composite betaine.

[0014] In the preparation of the compound betaine, the mass concentration of the calcium hydroxide suspension is 30%.

[0015] The mass concentration of the chloroacetic acid aqueous solution is 20%.

[0016] The mass concentration of the trimethylamine aqueous solution is 30%.

[0017] The mass ratio of calcium hydroxide suspension, chloroacetic acid aqueous solution, trimethylamine aqueous solution, polyethylene glycol 2000, and sodium dodecyl sulfate is 140-150:500-520:370-400:27-30:3.8-4.

[0018] The dropping rate of the chloroacetic acid aqueous solution is 30-50 g / min;

[0019] The trimethylamine aqueous solution was added at a rate of 30-50 g / min;

[0020] The concentration refers to concentrating the volume to 35-40% of its original volume.

[0021] The particle size of the compound betaine is 200-300 mesh;

[0022] The mixture consists of betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine, which are mixed evenly and then dried to obtain a betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost.

[0023] In the mixture, the free amino acid is glycine with a particle size of 100 mesh;

[0024] The inorganic calcium is calcium nitrate with a particle size of 40 mesh.

[0025] The boron source is borax with a particle size of 100 mesh;

[0026] The mass ratio of betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine is 42-45:5.5-6:23-25:6-6.5:4-4.2:5-5.4:0.3:3.4-3.7.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) According to the effect of surfactant CTAB on the colloidal forces between silica surfaces, as published in Zhang Yan et al., Petroleum Refining and Chemical Engineering, April 2020, in a low-concentration solution without electrolytes, CTAB achieves monolayer adsorption on the negatively charged silica surface through electrostatic interaction, i.e., the hydrophilic groups face the silica surface and the hydrophobic groups face the aqueous solution, which enhances the hydrophobicity of the silica substrate surface. In this invention, after coating the negatively charged silica surface with a layer of hexadecyltrimethylammonium bromide through electrostatic interaction, sodium dodecyl sulfate is added. The hydrophobic groups of sodium dodecyl sulfate face the silica and the hydrophilic groups face the aqueous solution, resulting in hydrophilic silica with a hydrophobic layer, i.e., an anti-caking agent. The anti-caking agent can play a mechanical isolation role, the hydrophobic layer can prevent water penetration, and the outermost hydrophilic groups can promote the dissolution of the anti-caking agent.

[0029] (2) According to the research on the new process of betaine synthesis, Yang Guan'e et al., Chinese Journal of Pharmaceutical Chemistry, June 2001, calcium hydroxide can be used to replace sodium hydroxide in the production of betaine. After the preparation is completed, the reactants contain calcium chloride. As a betaine production enterprise, the applicant has made innovations on the above method. Specifically, after the reaction is completed, instead of removing calcium chloride, polyethylene glycol 2000 and sodium dodecyl sulfate are directly added to coordinate or chelate with calcium ions to form a complex. At the same time, there is also an interaction between polyethylene glycol 2000 and betaine, thus obtaining a complex of polyethylene glycol 2000, sodium dodecyl sulfate, calcium ions and betaine, namely, composite betaine. Polyethylene glycol 2000 and sodium dodecyl sulfate in the compound betaine act as polymer-surfactant solubilizer-type anti-caking agents, which can prevent the connection between crystal grains. Sodium dodecyl sulfate in the compound betaine can form a repulsive force with sodium dodecyl sulfate on the surface of the anti-caking agent, further playing the role of anti-caking. Moreover, by adding anti-caking components and calcium ions to betaine to make a compound betaine, it can bind to the surface of other components through the adsorption of betaine and calcium ions, reducing the capillary adsorption force of other components on the solution, and further reducing hygroscopicity.

[0030] (3) The fertilizer of the present invention has good effects in reducing fruit cracking and preventing late spring frost. When applied to the planting of 'Meizao' cherry trees, the yield per tree can reach 36.1-36.5 kg, the average weight of a single fruit can reach 9.31-9.38 g, the fruit firmness can reach 188.9-190.1 g / mm, and the soluble solids content can reach 19.0-19.2%. After soaking in the diluted fertilizer solution of the present invention for 6 hours, the fruit cracking rate is 10.81-11.13%.

[0031] (4) The fertilizer of the present invention has strong anti-caking ability and still has excellent anti-caking ability at high storage temperature. After standing for 10 days in an environment with a temperature of 20°C and a relative humidity of 70%, the caking rate is 0.7-1.2%, and after standing for 10 days in an environment with a temperature of 50°C and a relative humidity of 70%, the caking rate is 2.8-3.5%.

[0032] (5) The fertilizer of the present invention does not require granulation and coating during preparation, and has low requirements for raw materials;

[0033] (6) The fertilizer of the present invention will not precipitate after dissolving. Detailed Implementation

[0034] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0035] Example 1

[0036] A betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost is prepared according to the following method:

[0037] 1. Preparation of anti-caking agent: Mix 100g of silica and 1000g of water, stir at 100rpm at room temperature for 30min, add 0.1g of hexadecyltrimethylammonium bromide, continue stirring for 30min, add 0.23g of sodium dodecyl sulfate, continue stirring for 60min, centrifuge at 5000rpm for 10min, collect the precipitate, dry it, and obtain the anti-caking agent;

[0038] The silica has a particle size of 2 μm;

[0039] 2. Preparation of compound betaine: At room temperature, 140g of calcium hydroxide suspension with a mass concentration of 30% was stirred at 100rpm, and then 500g of chloroacetic acid aqueous solution with a mass concentration of 20% was added dropwise at a rate of 30g / min. After the addition was completed, the solution was filtered, and the filtrate was collected. At room temperature, the filtrate was stirred at 100rpm, and then 370g of trimethylamine aqueous solution with a mass concentration of 30% was added dropwise at a rate of 30g / min. After the addition was completed, the solution was stirred for 30min, heated to 50℃, stirred for 70min, heated to 70℃, stirred for 70min, cooled to room temperature, and 27g of polyethylene glycol 2000 and 3.8g of sodium dodecyl sulfate were added. The solution was stirred for 30min, concentrated to 35% of the original volume, vacuum dried, and ground to a particle size of 200 mesh to obtain compound betaine.

[0040] 3. Mixing: Mix betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine evenly, and dry to obtain a betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost.

[0041] The free amino acid is glycine with a particle size of 100 mesh;

[0042] The inorganic calcium is calcium nitrate with a particle size of 40 mesh.

[0043] The boron source is borax with a particle size of 100 mesh;

[0044] The mass ratio of betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine is 42:5.5:23:6:4:5:0.3:3.4.

[0045] Example 2

[0046] A betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost is prepared according to the following method:

[0047] 1. Preparation of anti-caking agent: Mix 100g of silica and 1100g of water, stir at 200rpm at room temperature for 40min, add 0.11g of hexadecyltrimethylammonium bromide, continue stirring for 40min, add 0.24g of sodium dodecyl sulfate, continue stirring for 70min, centrifuge at 5500rpm for 12min, collect the precipitate, dry it, and obtain the anti-caking agent;

[0048] The silica has a particle size of 2 μm;

[0049] 2. Preparation of compound betaine: At room temperature, 145g of 30% calcium hydroxide suspension was stirred at 200rpm, and then 510g of 20% chloroacetic acid aqueous solution was added dropwise at a rate of 40g / min. After the addition was completed, the solution was filtered, and the filtrate was collected. At room temperature, the filtrate was stirred at 200rpm, and then 380g of 30% trimethylamine aqueous solution was added dropwise at a rate of 40g / min. After the addition was completed, the solution was stirred for 35min, heated to 55℃ and stirred for 80min, heated to 75℃ and stirred for 80min, cooled to room temperature, and 28g of polyethylene glycol 2000 and 3.9g of sodium dodecyl sulfate were added. The solution was stirred for 35min and concentrated to 40% of the original volume. The solution was then vacuum dried and ground to a particle size of 300 mesh to obtain compound betaine.

[0050] 3. Mixing: Mix betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine evenly, and dry to obtain a betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost.

[0051] The free amino acid is glycine with a particle size of 100 mesh;

[0052] The inorganic calcium is calcium nitrate with a particle size of 40 mesh.

[0053] The boron source is borax with a particle size of 100 mesh;

[0054] The mass ratio of betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine is 44:5.8:24:6.2:4.1:5.2:0.3:3.5.

[0055] Example 3

[0056] A betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost is prepared according to the following method:

[0057] 1. Preparation of anti-caking agent: Mix 100g of silica and 1200g of water, stir at 300rpm at room temperature for 50min, add 0.11g of hexadecyltrimethylammonium bromide, continue stirring for 50min, add 0.25g of sodium dodecyl sulfate, continue stirring for 80min, centrifuge at 6000rpm for 15min, collect the precipitate, dry it, and obtain the anti-caking agent;

[0058] The silica has a particle size of 2 μm;

[0059] 2. Preparation of compound betaine: At room temperature, 150g of 30% calcium hydroxide suspension was stirred at 300rpm, and then 520g of 20% chloroacetic acid aqueous solution was added dropwise at a rate of 50g / min. After the addition was completed, the solution was filtered, and the filtrate was collected. At room temperature, the filtrate was stirred at 300rpm, and then 400g of 30% trimethylamine aqueous solution was added dropwise at a rate of 50g / min. After the addition was completed, the solution was stirred for 40min, heated to 60℃, stirred for 90min, heated to 80℃, stirred for 90min, cooled to room temperature, and 30g of polyethylene glycol 2000 and 4g of sodium dodecyl sulfate were added. The solution was stirred for 40min and concentrated to 40% of the original volume. The solution was then vacuum dried and ground to a particle size of 300 mesh to obtain compound betaine.

[0060] 3. Mixing: Mix betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine evenly, and dry to obtain a betaine-containing fertilizer that reduces fruit cracking and prevents late spring frost.

[0061] The free amino acid is glycine with a particle size of 100 mesh;

[0062] The inorganic calcium is calcium nitrate with a particle size of 40 mesh.

[0063] The boron source is borax with a particle size of 100 mesh;

[0064] The mass ratio of betaine, betaine phosphate, free amino acids, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and compound betaine is 45:6:25:6.5:4.2:5.4:0.3:3.7.

[0065] Comparative Example 1

[0066] Based on the technical solution of Example 1, the step of preparing the anti-caking agent in step 1 is omitted, and the addition of the anti-caking agent is omitted in the mixing step in step 3.

[0067] Comparative Example 2

[0068] Based on the technical solution of Example 1, the second step of preparing compound betaine is omitted, and the addition of compound betaine is omitted in the third step of mixing.

[0069] Test Example 1

[0070] The fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 were weighed (weight as m0) and packaged and sealed using 8×12cm plastic sealed bags. A 2kg weight was then placed on top of the bags, and the bags were left to stand for 10 days at 20℃ and 70% relative humidity. The bags were then dropped once from a height of 1m on both sides. The packaging was opened, and the fertilizer was sieved through a 10-mesh sieve. The residue on the sieve was taken as the agglomerated fertilizer. The agglomerated fertilizer was dried and weighed (weight as m). The agglomeration rate was then calculated. The results are as follows:

[0071] clumping rate = m / m0 × 100%

[0072] The calculated clumping rate results are as follows:

[0073]

[0074] Test Example 2

[0075] The fertilizers prepared in Examples 1-3 and Comparative Examples 1-2 were weighed (weight as m0) and packaged and sealed using 8×12cm plastic sealed bags. A 2kg weight was then placed on top of the bags, and the bags were left to stand for 10 days at 50℃ and 70% relative humidity. The bags were then dropped once from a height of 1m on both sides. The packaging was opened, and the fertilizer was sieved through a 10-mesh sieve. The residue on the sieve was taken as the agglomerated fertilizer. The agglomerated fertilizer was dried and weighed (weight as m). The agglomeration rate was then calculated. The results are as follows:

[0076] clumping rate = m / m0 × 100%

[0077] The calculated clumping rate results are as follows:

[0078]

[0079] The results of Test Example 1 and Test Example 2 show that the fertilizers of Examples 1-3 have strong anti-caking ability and the anti-caking ability is less affected by temperature.

[0080] Test Example 3

[0081] Take 10g of fertilizer from Examples 1-3 and Comparative Examples 1-2 respectively, add it to 1500g of water, stir at 100rpm for 3 minutes at room temperature, let stand for 15 minutes, and observe whether there is any precipitation. The results are as follows:

[0082]

[0083] The results above show that the fertilizers of Examples 1-3 and Comparative Examples 1-2 did not precipitate after dissolution.

[0084] Test Example 4

[0085] The fertilizers from Examples 1-3 and Comparative Examples 1-2 were applied to cherry cultivation, and the application methods and results are as follows:

[0086] In a cherry orchard in Feicheng City, Tai'an City, Shandong Province, 20 'Meizao' cherry trees with uniform growth, no obvious pests or diseases, and planted at the same time were selected. The 20 'Meizao' cherry trees were arranged in the same row to facilitate unified management. The 2nd to 19th trees along the roadside were selected as test trees (the 1st and 20th trees along the roadside were not selected as test trees due to significant differences in light and temperature conditions). The test trees were divided into 6 groups on average.

[0087] The fertilizers used in Examples 1-3 and Comparative Examples 1-2 were applied to groups 1-5 for the first spraying treatment on March 30, 2025, and for the second spraying treatment on April 15, 2025. Before each spraying treatment, the fertilizer was diluted 150 times and then sprayed onto the cherry tree leaves. The spraying standard was to spray until both sides of the leaves were moistened and began to drip. Six groups served as blank controls, receiving no fertilizer.

[0088] On May 18, 2025, after the fruit ripened, all the fruit on the tree was harvested. The yield per tree and the average weight of a single fruit were measured, and the average value for each group was calculated. Ten cherries were also collected from the southern side of the canopy of each cherry tree, at a height of 1.3-1.7 meters, at the tip of the main branch. Fruit firmness and soluble solids content (commonly known as sugar content) were measured, and the average value for each group was calculated. The results are as follows:

[0089]

[0090] In the tests, the fruit hardness was measured using a Firmtech FT-11 benchtop non-destructive hardness tester from Germany, and the soluble solids content of the fruit was measured using an ATAGO digital display sugar and acidity meter from Japan.

[0091] Due to the drought in the spring and summer of 2025, there were fewer fruit cracks in the field, making it impossible to effectively compare the differences between different treatments by measuring the cracking rate. Therefore, the water immersion method was used to statistically analyze the crack resistance of fruits under different treatments. Specifically, 50 cherry trees were selected on the south side of the canopy of each cherry tree, at a height of 1.3-1.7 meters, at the tip of the main branch. The fertilizers from Examples 1-3 and Comparative Examples 1-2 were diluted to a 150-fold dilution. The selected cherries from groups 1-5 were then immersed in the solution for 6 hours. Meanwhile, group 6 served as a blank control, immersing the cherries in clean water for 6 hours. After the immersion treatment, the cracking rate was measured, and the average value for each group was calculated. The results are as follows:

[0092]

[0093] The results above show that the synergistic effects of betaine, free amino acids, inorganic calcium, EDTA chelated calcium, and boron source in Examples 1-3 and Comparative Examples 1-2 can effectively increase yield, single fruit weight, fruit firmness, soluble solids content, and reduce fruit cracking rate.

Claims

1. A betaine-containing fertilizer for reducing fruit cracking and preventing late spring frost, characterized by, Preparation of the anti-caking agent, preparation of the composite betaine, mixing are carried out according to the following steps: In the preparation of the anti-caking agent, the silica and water are mixed, then stirred at room temperature, then the cetyltrimethylammonium bromide is added and stirred, then the sodium dodecyl sulfate is added and stirred, then centrifuged, then the precipitate is taken and dried to obtain the anti-caking agent; In the preparation of the anti-caking agent, the mass ratio of the silica, water, cetyltrimethylammonium bromide, and sodium dodecyl sulfate is 100:1000-1200:0.1-0.11:0.23-0.25; In the preparation of the composite betaine, the calcium hydroxide suspension is stirred at room temperature, then the aqueous chloroacetic acid solution is added dropwise, then filtered after the dropwise addition is completed, then the filtrate is stirred at room temperature, then the aqueous trimethylamine solution is added dropwise, then stirred after the dropwise addition is completed, then heated to 50-60°C and stirred, then heated to 70-80°C and stirred, then cooled to room temperature, then the polyethylene glycol 2000 and sodium dodecyl sulfate are added and stirred, then concentrated, then vacuum dried, then ground to obtain the composite betaine; In the preparation of the composite betaine, the mass ratio of the calcium hydroxide suspension, aqueous chloroacetic acid solution, aqueous trimethylamine solution, polyethylene glycol 2000, and sodium dodecyl sulfate is 140-150:500-520:370-400:27-30:3.8-4; In the mixing, the betaine, betaine phosphate, free amino acid, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and composite betaine are uniformly mixed and dried to obtain the betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold; In the mixing, the mass ratio of the betaine, betaine phosphate, free amino acid, inorganic calcium, EDTA chelated calcium, boron source, anti-caking agent, and composite betaine is 42-45:5.5-6:23-25:6-6.5:4-4.2:5-5.4:0.3:3.4-3.

7.

2. The betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold according to claim 1, characterized by, In the preparation of the anti-caking agent, the particle size of the silica is 2 μm.

3. The betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold according to claim 1, characterized by, In the preparation of the composite betaine, the mass concentration of the calcium hydroxide suspension is 30%; The mass concentration of the aqueous chloroacetic acid solution is 20%; The mass concentration of the aqueous trimethylamine solution is 30%.

4. The betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold according to claim 1, characterized by, In the preparation of the composite betaine, the dropwise addition speed of the aqueous chloroacetic acid solution is 30-50 g / min; The dropwise addition speed of the aqueous trimethylamine solution is 30-50 g / min; The concentration is concentrated to 35-40% of the original volume.

5. The betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold according to claim 1, characterized by, In the preparation of the composite betaine, the particle size of the composite betaine is 200-300 mesh.

6. The betaine-containing fertilizer for reducing fruit cracking and preventing early spring cold according to claim 1, characterized by, In the mixing, the free amino acid is glycine with a particle size of 100 mesh; The inorganic calcium is calcium nitrate with a particle size of 40 mesh; The boron source is borax with a particle size of 100 mesh.

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