Calcium-containing growth protectant for bag-free fruit and preparation method therefor and use thereof

Abstract

Disclosed is a calcium-containing growth protectant for bag-free fruit, starting materials thereof comprising, in parts by mass: 1-20 parts of a monodisperse micro-nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxy-modified polytrisiloxane, 0-0.8 parts of a polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.8 parts of an enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water. The polyvinyl acetate emulsion and glycerol cannot both be zero simultaneously. The calcium-containing growth protectant is non-toxic, and after being diluted with water to a calcium carbonate solid content of 0.5%-6%, is sprayed onto the surface of fruit crops for use in bag-free fruit cultivation, which can significantly improve the taste and quality of fruit compared to bag cultivation.

Description

A calcium-containing growth protectant for bagged-free fruits, its preparation method and application

[0001] Cross-reference to related applications This application is based on Chinese Patent Application No. 202411921005.8, filed on December 25, 2024, and claims priority to that Chinese Patent Application, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of plant growth regulators, specifically relating to a calcium-containing growth protectant for fruit that does not require bagging and its application in fruit cultivation without bagging. Background Technology

[0003] Due to the significant threat of pests, current fruit cultivation commonly uses paper or plastic bags to cover the fruit for bagging. This physical protection method effectively protects the fruit from insect damage and is widely used. However, it also significantly increases the labor costs in the fruit cultivation process. Furthermore, bagging can affect the photosynthesis of the fruit, resulting in a decline in the taste and nutritional value of the fruit. Therefore, there is an urgent need for an effective bagging-free fruit cultivation method.

[0004] Currently, there are various plant growth regulators and protectants on the market, such as gibberellic acid, amino acid esters, anti-drop agents, and benzylaminopurine for increasing yield; amino acid-containing water-soluble fertilizers for cold resistance; and lime milk whitewash for high-temperature resistance. Using these plant growth regulators can promote or protect the growth of crops, fruits, and vegetables. However, some of these plant growth regulators have complex preparation methods; for example, the production of gibberellic acid for increasing yield requires multiple processes such as strain cultivation, fermentation, extraction, and purification. Some components are expensive, resulting in high usage costs, such as amino acid-containing water-soluble fertilizers. Some products, like lime milk whitewash, often experience sedimentation and clumping during use; and some even cause soil environmental damage. More importantly, these growth regulators generally have limited functionality, often emphasizing production promotion while offering weak protection against pests and diseases, and cannot replace the function of fruit bagging. Therefore, there is an urgent need to develop a plant protection product that can effectively protect fruits from pests and diseases, provide some nutritional support for plant growth, and is inexpensive to use. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a calcium-containing growth protectant for bagged-free fruits. This calcium-containing growth protectant is non-toxic and can be sprayed directly onto the surface of the fruit crop. It can replace traditional fruit bagging and is used for bagged-free fruit cultivation. It has good physical insect-repellent and pest-control effects, significantly improving the fruit's disease and insect resistance and reducing diseased and insect-infested fruit.

[0006] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0007] A calcium-containing growth protectant for fruit that does not require bagging, comprising the following raw materials by weight: 1-20 parts of monodisperse micro / nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxylated modified polytrisiloxane, 0-0.8 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.8 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water; wherein the polyvinyl acetate emulsion and glycerol are not simultaneously zero.

[0008] According to the above scheme, the monodisperse micro / nano calcium carbonate filter cake has the following characteristics: the filter cake has a moisture content of 35%~40%; the calcium carbonate particles are cubic or nearly spherical in shape, with an average particle size between 50 and 200 nm, and particles larger than 200 nm account for less than 5%; the particle surface is clean, monodisperse, and has low surface energy, with a specific surface area of ​​less than 20 m². 2 / g, with a preferred specific surface area of ​​16~18 m² 2 / g; the content of harmful metal elements such as cadmium in calcium carbonate is less than 200 ppm; the monodisperse micro-nano calcium carbonate filter cake can be stirred and dispersed in aqueous solution without the addition of any chemical dispersant and remains stably suspended. Specifically, the monodisperse micro-nano calcium carbonate filter cake is dispersed in water to obtain a suspension; when the solid content of the suspension is 2%, it can be stably suspended for more than 2 hours; when the solid content of the suspension is 5%~30%, it can be stably suspended for more than 14 hours.

[0009] According to the above scheme, the method for preparing the monodisperse micro / nano calcium carbonate filter cake includes the following steps:

[0010] S1. Calcium carbonate slurry was prepared using calcination, digestion, and carbonation processes. The calcination process involved selecting limestone with uniform grain size and a content of harmful heavy metals such as cadmium, lead, and chromium less than 400 ppm as raw material. A calcination temperature matching the grain size was used to obtain quicklime with ideal activity. The activity of the quicklime was between 250 and 300 mL (4 mol / L HCl, 40±1℃, 10 min), exhibiting good uniformity and consistency. The digestion process involved digesting the calcined quicklime in hot water at 50–90℃ to obtain lime slurry. The aging and impurity removal process involved aging the digested lime slurry for 24–48 hours. h, and after filtration to remove impurities, refined raw pulp is obtained; the carbonation process is as follows: water is added to the refined raw pulp to adjust the solid content to 5% to 12%, and then carbonation is carried out. The initial carbonation temperature is 10 to 30℃, and the CO2 content is 20% to 40% (here, CO2 content refers to the content of carbon dioxide in the carbonation atmosphere during the carbonation process. For the carbonation process, carbonation is carried out by introducing carbon dioxide. A carbonation atmosphere with a certain CO2 content is sufficient. Pure carbon dioxide atmosphere is rarely used directly, as this is conducive to controlling the reaction progress of the carbonation process). Carbonation is carried out until the pH of the pulp reaches 7.5 to 9.0, and then carbonation is ended to obtain calcium carbonate cooked pulp;

[0011] The calcium carbonate particles in the calcium carbonate slurry are nearly spherical or chain-like. The average particle size of the nearly spherical particles is 30~100 nm, and the average width (lateral dimension) of the chain-like particles is 30~100 nm.

[0012] S2. Add an inorganic salt grain surface remodeling agent and an organic grain surface remodeling agent to the calcium carbonate slurry obtained in S1, and then keep it at 140~200℃ for 1.0~4.0 h to obtain a calcium carbonate suspension. The inorganic grain surface remodeling agent is one or more inorganic salts such as sodium silicate, sodium chloride, aluminum chloride, and zinc sulfate, and is used in an amount of 0.5%~3% of the dry weight of calcium carbonate. The organic grain surface remodeling agent is one or more organic compounds such as ethanol, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and disodium ethylenediaminetetraacetate, and is used in an amount of 1%~5% of the dry weight of calcium carbonate.

[0013] S3. The calcium carbonate suspension obtained in S2 is dehydrated by hydraulic filtration to obtain a calcium carbonate filter cake. The moisture content of the filter cake is controlled between 35% and 40%, i.e., a monodisperse micro / nano calcium carbonate filter cake. This meets the following criteria: the calcium carbonate particles are cubic or nearly spherical in shape, with an average particle size between 50 and 200 nm, and particles larger than 200 nm accounting for less than 5%; the particle surface is clean, monodisperse, and has low surface energy, with a specific surface area of ​​less than 20 m². 2 / g; the content of harmful metal elements such as cadmium in calcium carbonate is less than 200 ppm; it can be dispersed in aqueous solution without the addition of any chemical dispersant after stirring and remains in stable suspension.

[0014] The preparation method of the calcium-containing growth protectant for the above-mentioned bag-free fruits includes the following steps:

[0015] (1) According to the proportions of each raw material and mass of the calcium-containing growth protectant described in this invention, prepare 1-20 parts of monodisperse micro-nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxylated modified polytrisiloxane, 0-0.8 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.8 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water;

[0016] (2) Place the monodisperse micro-nano calcium carbonate filter cake in a small amount of water at a temperature of 5~30℃ (the weight of the “small amount of water” is 1~2 times the weight of the monodisperse micro-nano calcium carbonate filter cake in the formula), and disperse it in a high-speed disperser at a linear velocity of 80~120 m / min at room temperature for 15~40 min.

[0017] (3) After the stirring in step (2) is completed, add the remaining raw materials and the remaining water, and continue to disperse in a high-speed disperser at a linear speed of 80~120 m / min for 15~30 min to obtain the calcium-containing growth protectant for bag-free fruit described in this invention.

[0018] The calcium-containing growth protectant for bagless fruits of this invention can be further diluted according to different application scenarios. When used to prevent fruit cracking and improve coloring, dilute with water to a calcium carbonate solid content of 0.5%~2% before spraying; when used to prevent pests and reduce fruit drop, the optimal calcium carbonate solid content is 1%~3% before dilution with water before spraying.

[0019] According to the above scheme, the bag-free fruits mentioned in this invention include apples, citrus fruits, pears, plums, mangoes, cherry tomatoes, grapes, dragon fruit, oranges, loquats, apricots, kiwifruit, pomelos, pomegranates, jujubes, guavas, peaches, etc.

[0020] The calcium-containing growth protectant described in this invention can be used for fruit cultivation without bagging. The application method is as follows: In dry weather without rain, the growth protectant described in this invention is diluted and sprayed onto the surface of the fruit. There is no need to avoid branches and leaves. Depending on the type of fruit, it needs to be sprayed 2 to 4 times during the fruit ripening process. If there is more than 5 days of rainfall within 24 hours after spraying, and the total rainfall reaches 250 mm or more, it is necessary to spray again after the rain.

[0021] This invention uses limestone with uniform grain size and a content of harmful heavy metals such as cadmium, lead, and chromium of less than 400 ppm as raw material to prepare monodisperse micro / nano calcium carbonate filter cake. Then, a calcination temperature matching the grain size is used to obtain quicklime with moderate and uniform activity. This quicklime is then digested and carbonized to obtain a calcium carbonate slurry. The uniform grain size of the limestone is used to adjust the lime activity through a limestone calcination process, avoiding partial under-burning and over-burning caused by mottled grains. The good uniformity and moderate activity of the lime facilitate the control of the digestion reaction, obtaining a homogeneous lime slurry with controllable properties, thereby enabling control of the subsequent carbonation process and obtaining a calcium carbonate slurry with the desired particle size and grain morphology. The content of harmful heavy metals such as cadmium, lead, and chromium in the limestone is less than 400 ppm, ensuring that the content of harmful heavy metals in the prepared monodisperse micro / nano calcium carbonate filter cake is less than 200 ppm.

[0022] After carbonization, a grain surface reconstruction process is performed by adding inorganic and organic surface reconstruction agents and maintaining the temperature at a certain level. This promotes grain surface reconstruction, resulting in more complete crystals, smoother particle surfaces, and reduced surface energy, thus facilitating dispersion. The inorganic surface reconstruction agent promotes crystal development, repairs defects, and makes the crystals more complete; the organic surface reconstruction agent regulates the surface potential of the particles, controls the mutual repulsion of the grains in water, and prevents adhesion during the crystal repair process. This invention controls the average particle size of calcium carbonate particles to 50-200 nm and achieves a highly monodisperse state by controlling the temperature and time of grain surface reconstruction. This morphology of calcium carbonate particles ensures visible light diffraction transmission, thus not affecting fruit photosynthesis and surface coloring. Simultaneously, it effectively absorbs harmful ultraviolet light (for example, when the calcium-containing growth protectant described in this invention is diluted to a calcium carbonate solid content of 2% and sprayed to form a film, the absorption of ultraviolet light can reach over 85%, while the absorption of visible light is less than 15%). The monodisperse micro / nano calcium carbonate slurry obtained through grain surface reconstruction is then subjected to pressure filtration or centrifugation to obtain a monodisperse micro / nano calcium carbonate filter cake with the desired particle size. Pressure filtration and centrifugation remove excess water, forming a monodisperse micro / nano calcium carbonate filter cake, which facilitates the processing and transportation of calcium carbonate. Simultaneously, it rapidly reduces other soluble ions present in the solution during production, ensuring that the use and effectiveness of the calcium-containing growth protectant of this invention are not affected or interfered with.

[0023] Based on the above, this invention uses the monodisperse micro / nano calcium carbonate filter cake as the main raw material, and mixes it with other raw materials and disperses it in water to obtain the calcium-containing growth protectant for bagged fruits described in this invention. The monodisperse micro / nano calcium carbonate filter cake maintains 35%–40% moisture content, preserving a water film and electric double layer structure between the calcium carbonate solid particles. This maximizes the preservation of the surface state and repulsive forces of the calcium carbonate particles, preventing agglomeration. Therefore, it can be rapidly redispersed in the aqueous solution during assisted stirring in a disperser and maintain stable suspension.

[0024] The calcium-containing growth protectant for bagged fruit described in this invention, when sprayed onto the surface of the fruit, can quickly form a light-colored protective film, effectively resisting pests and diseases. Due to the special particle size and dispersion design of calcium carbonate, the protective film does not affect the transmission of visible light, thus not affecting the photosynthesis of the fruit. This invention utilizes the ultraviolet light absorption and infrared radiation characteristics of calcium carbonate, combined with the particle size design of this invention, to effectively reduce the temperature of the fruit, forming effective physical and optical protection.

[0025] This invention adds modified casein as a film-forming agent with good air permeability and strong adhesion. At the same time, its main component, casein, can promote plant growth and development, improve fertilizer efficiency and yield, and is beneficial to increasing crop yield in the later stages.

[0026] This invention can effectively prevent and control pests by adding enzymes; in addition, it contains polysaccharides, amino acids and other components, which, when used in combination with calcium carbonate, can improve the level of plant absorption of micro- and nano-calcium carbonate.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The growth protectant described in this invention is safe and non-toxic, and can replace bagging for fruit cultivation without bagging. It is sprayed directly onto the surface of the fruit crop and has a good physical insect control effect. It can replace bagging, significantly improve the disease and insect resistance of fruit trees, and reduce diseased and insect-infested fruit.

[0029] 2. The growth protectant described in this invention is sprayed on the surface of the fruit to meet the calcium requirements of fruit crops during growth, effectively inhibit fruit cracking and fruit drop, increase fruit fullness, and improve the calcium content of the fruit. At the same time, it can increase the yield compared with bagged fruit and significantly improve the taste and quality of the fruit.

[0030] 3. The growth protectant described in this invention can effectively absorb ultraviolet rays and radiate infrared rays, reducing fruit surface temperature. It does not affect the transmission of visible light and does not interfere with the normal photosynthesis of fruit crops. When used for fruit cultivation without bagging, it can significantly improve the taste and quality of fruit grown with bags. Attached Figure Description

[0031] Figure 1 is a scanning electron microscope image of calcium carbonate particles in the calcium carbonate slurry prepared in Example 1.

[0032] Figure 2 is a scanning electron microscope image of the micro / nano calcium carbonate prepared in Example 1;

[0033] Figure 3 shows the effect of the growth protectant prepared in Example 1 on apples;

[0034] Figure 4 is a scanning electron microscope image of calcium carbonate particles in the calcium carbonate slurry prepared in Example 2.

[0035] Figure 5 is a scanning electron microscope image of the micro / nano calcium carbonate prepared in Example 2;

[0036] Figure 6 shows the effect of the growth protectant prepared in Example 2 on pears;

[0037] Figure 7 is a scanning electron microscope image of calcium carbonate particles in the calcium carbonate slurry prepared in Example 3.

[0038] Figure 8 is a scanning electron microscope image of the micro / nano calcium carbonate prepared in Example 3;

[0039] Figure 9 shows the effect of the growth protectant prepared in Example 3 on Prunus cerasifera.

[0040] Figure 10 is a comparison of the effects of spraying the growth protectant prepared in Example 3 on mature fruit of the plum tree with that of bagged fruit.

[0041] Figure 11 shows the fruit fly infestation and rotten fruit condition of unsprayed plums when they are ripe;

[0042] Figure 12 is a scanning electron microscope image of calcium carbonate particles in the calcium carbonate slurry prepared in Example 4.

[0043] Figure 13 is a scanning electron microscope image of the micro / nano calcium carbonate prepared in Example 4;

[0044] Figure 14 is a scanning electron microscope image of calcium carbonate particles in the calcium carbonate slurry prepared in Example 5.

[0045] Figure 15 is a scanning electron microscope image of the micro / nano calcium carbonate prepared in Example 5;

[0046] Figure 16 is a scanning electron microscope image of the calcium carbonate prepared in Comparative Example 1.

[0047] Figure 17 is a comparison diagram of the effects of calcium carbonate prepared in the examples and comparative examples dispersed in water;

[0048] Figure 18 shows the effect of the growth protectant made from calcium carbonate in Comparative Example 1 on apples and a comparison of the fruit coloring after ripening with that in Example 1.

[0049] Figure 19 is a scanning electron microscope image of the calcium carbonate prepared in Comparative Example 2.

[0050] Figure 20 shows the effect of the growth protectant made from calcium carbonate (Comparative Example 2) on pears.

[0051] Figure 21 shows the effect of the growth protectant made from calcium carbonate (Comparative Example 3) on Prunus armeniaca.

[0052] Figure 22 shows the effect of the growth protectant made from calcium carbonate (Comparative Example 4) on apples.

[0053] Figure 23 shows the effect of the growth protectant made from calcium carbonate (Comparative Example 5) on pears.

[0054] Specific implementation methods

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0056] This invention provides a calcium-containing growth protectant for fruit that does not require bagging. The raw materials, calculated by weight, include: 1-20 parts of monodisperse micro / nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxylated modified polytrisiloxane, 0-0.8 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.8 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water; wherein the polyvinyl acetate emulsion and glycerol are not simultaneously zero.

[0057] In some specific embodiments, the calcium-containing growth protectant for bagless fruits comprises, by weight, the following components: 1-20 parts of monodisperse micro / nano calcium carbonate filter cake, 0.05-0.5 parts of ethoxylated modified polytrisiloxane, 0.02-0.9 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.5 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water.

[0058] In some specific embodiments, the mass of the monodisperse micro / nano calcium carbonate filter cake is 15 to 75 times that of ethoxylated modified polytrisiloxane, preferably 15 to 40 times.

[0059] In some specific embodiments, the mass of water is 3 to 12 times that of the monodisperse micro / nano calcium carbonate filter cake, preferably 5 to 9 times.

[0060] Furthermore, the mass of the monodisperse micro / nano calcium carbonate filter cake is 15 to 200 times that of the polyvinyl acetate emulsion, preferably 18.75 to 50 times.

[0061] In some specific embodiments, the mass of monodisperse micro / nano calcium carbonate filter cake is 25 to 100 times that of modified casein.

[0062] In some specific embodiments, the mass of the monodisperse micro / nano calcium carbonate filter cake is preferably 25 to 100 times that of the enzyme.

[0063] In some specific embodiments, the mass of the monodisperse micro / nano calcium carbonate filter cake is 15 to 200 times that of the sugar alcohol, preferably 50 to 100 times.

[0064] In some specific embodiments, the sugar alcohol includes one or more of xylitol, ribitol, mannitol, sorbitol, maltitol, erythritol, and lactitol. All sugar alcohols are commercially available products with an active ingredient content greater than 70%.

[0065] In some specific embodiments, the modified casein is a milky white viscous liquid with a solid content of 15%–25%, a viscosity (at 20°C) greater than 100 mPa·s, and a pH value (10% aqueous solution) of 7–8. Specifically, in the following examples, the modified casein is an emulsion obtained by dissolving commercially available casein in weak alkaline water at 50–65°C. It appears as a milky white viscous liquid with a solid content of 20.0 ± 2.0%, a viscosity (at 20°C) greater than 100 mPa·s, and a pH value (10% aqueous solution) of 7–8. The casein was purchased from Gansu Hualing Dairy Co., Ltd., and its product type is edible casein.

[0066] In the following examples, the enzyme is a commercially available agricultural enzyme, the main component of which is an agricultural biological agent, and it also contains polysaccharides, amino acids and other components. It was purchased from Jining Alida Biotechnology Co., Ltd., model: MLQ-Plant Enzyme.

[0067] In the following examples, the ethoxylated modified polytrisiloxane is a commercially available product purchased from GE Silicones USA, model number Silwet, with an active ingredient content greater than 98%.

[0068] In the following examples, the polyvinyl acetate emulsion is a commercially available reagent, also known as polyvinyl acetate, CAS No.: 9003-20-7.

[0069] In the following examples, the glycerol is a commercially available reagent, CAS No.: 56-81-5.

[0070] Example 1

[0071] This embodiment provides a calcium-containing growth protectant for bagged fruits, which is formulated from the following raw materials in parts by weight: 1 part monodisperse micro-nano calcium carbonate filter cake, 0.05 parts ethoxylated modified polytrisiloxane, 0.02 parts polyvinyl acetate emulsion, 0.01 parts glycerol, 0.01 parts modified casein, 0.01 parts enzyme, 0.01 parts maltitol, and 5 parts water.

[0072] The preparation method of the calcium-containing growth protectant for bagged fruit described in this embodiment is as follows: According to the above raw materials and mass proportions, 1 part of monodisperse micro-nano calcium carbonate filter cake is placed in 2 parts of water, and stirred for 40 min at a stirring linear speed of 80 m / min using a high-speed disperser. Then, according to the above formula, 0.05 parts of ethoxylated modified polytrisiloxane, 0.02 parts of polyvinyl acetate emulsion, 0.01 parts of glycerol, 0.01 parts of modified casein, 0.01 parts of enzyme, 0.01 parts of maltitol, and the remaining 3 parts of water are added, and stirring is continued at a stirring linear speed of 80 m / min for 20 min to obtain the growth protectant described in this embodiment, with a calcium carbonate solid content of approximately 10%.

[0073] In this embodiment, the preparation steps of the monodisperse micro / nano calcium carbonate filter cake are as follows:

[0074] S1. Calcium carbonate slurry is prepared using calcination, digestion, and carbonation processes. The calcination process involves selecting limestone with a grain size of 0.2–0.5 mm and a content of harmful heavy metals such as cadmium, lead, and chromium of less than 400 ppm as raw material. Calcination is carried out at 900℃ for 2 hours to obtain ideally active quicklime. The digestion process involves digesting the calcined quicklime with water at 90℃ to obtain lime milk, which is then aged for 24 hours to remove impurities and obtain refined raw slurry. The carbonation process involves adding water to the refined raw slurry obtained from digestion to adjust the solid content to 6%, followed by carbonation at an initial temperature of 10℃ and a CO2 content of 40%. Carbonation continues until the slurry pH reaches 8.5–9.0, at which point carbonation is terminated to obtain calcium carbonate slurry.

[0075] As can be observed from the scanning electron microscope image (see Figure 1), the calcium carbonate particles in the obtained slurry are nearly spherical, with an average particle size of about 23 nm.

[0076] S2. Add 0.5% aluminum chloride, 0.5% polyvinylpyrrolidone, 2.5% sodium dodecyl sulfate and 2.0% polyvinyl alcohol by weight of calcium carbonate dry basis to the calcium carbonate slurry obtained in S1, and keep it at 140℃ for 2.0 h to obtain calcium carbonate suspension.

[0077] S3. The calcium carbonate suspension obtained in S2 was dehydrated by hydraulic filtration to obtain a calcium carbonate filter cake. The moisture content of the filter cake was controlled between 35% and 40%, i.e., monodisperse micro / nano calcium carbonate. An appropriate amount of the filter cake was then dried at 105℃ and subjected to composition, specific surface area, microstructure, and particle size analysis. The composition and specific surface area tests were conducted according to the "Analytical Methods for Calcium Carbonate" (GB / T 19281-2014) standard, and the microstructure and particle size tests were conducted according to the "Nano Calcium Carbonate" (GB / T 19590-2023) standard. The content of harmful impurities such as cadmium, lead, barium, mercury, and arsenic in the obtained monodisperse micro / nano calcium carbonate was less than 0.0002%, and the total content of harmful impurities was less than 200 ppm; the specific surface area was approximately 19.89 m². 2 / g; Scanning electron microscopy images (see Figure 2) clearly show that the average particle size of the obtained monodisperse micro / nano calcium carbonate particles is about 65 nm, the particles are cubic, and the surface is flat and clean. The monodisperse micro / nano calcium carbonate filter cake was dispersed in water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 hours. It was still stably suspended (see Figure 17).

[0078] When used for apple spraying: Before the apple fruit enlargement period, dilute the growth protectant prepared in this embodiment 10 times (calcium carbonate solid content is approximately 1%) and spray it onto the surface of the apple fruit. There is no need to avoid the leaves and branches during spraying. After spraying, record the growth status of the entire apple tree by taking photos. Observe regularly every week thereafter. Spray 2-3 times during the apple ripening process. If there is continuous rainfall for more than 5 days, with a total rainfall of 250 mm or more, a re-spray is required after the rain. The orchards sprayed were Jinyuan Orchard, Huaibai Base Orchard, and Nanhesu Orchard.

[0079] Figure 3 shows the effect of using the growth protectant in this embodiment on apples.

[0080] Table 1 shows the effects of spraying the apple trees with the growth protectant of this embodiment on tree vigor indicators compared to bagging (ck). The table indicates that spraying the growth protectant of this embodiment can improve tree vigor. In the experiment, the fresh weight of 100 leaves in Jinyuan Orchard increased by 2.24%, the dry weight of 100 leaves decreased by 1.46%, and the thickness of 100 leaves increased by 1.17%; the fresh weight of 100 leaves in Huaibai Base Orchard increased by 5.22%, the dry weight of 100 leaves increased by 3.54%, and the thickness of 100 leaves increased by 3.95%; and the fresh weight of 100 leaves in Nanhesu Orchard increased by 6.17%, the dry weight of 100 leaves increased by 3.04%, and the thickness of 100 leaves increased by 8.637%.

[0081] Table 1 Comparison of Tree Vigor Indicators

[0082]

[0083] Table 2 shows the effects of spraying the apples with the growth protectant of this embodiment on fruit appearance indicators compared to bagging (ck). As the table shows, spraying with the growth protectant of this embodiment has little effect on the fruit shape index, but it can improve the brightness and color of the fruit. In the Jinyuan orchard, the brightness of the fruit increased by 9.9%, the redness increased by 19.8%, and the yellowness decreased by 31.8%; in the Huaibaiji orchard, the brightness increased by 5.5%, the redness increased by 18.7%, and the yellowness decreased by 28.6%; and in the Nanhesu orchard, the brightness increased by 19.6%, the redness increased by 43.5%, and the yellowness decreased by 10.8%.

[0084] Table 2 Comparison of Fruit Appearance Indicators

[0085]

[0086] (Note: In Table 2, 0.6 < Fruit Shape Index ≤ 0.8 represents oblate fruit, and 0.8 < Fruit Shape Index ≤ 0.9 represents round or nearly round fruit; L represents the brightness value.)

[0087] The effects of spraying apples with the growth protectant of this embodiment (SET) on the internal quality of the fruit, compared with bagging (CK), are shown in Table 3. The table shows that the growth protectant of this embodiment improves the internal quality of the fruit. In the experiment, in the Jinyuan orchard, the weight gain per fruit was 1.68%, firmness increased by 2.3%, soluble solids increased by 2.2%, titratable acid increased by 23.9%, and the sugar-acid ratio decreased by 17.5%; in the Huaibai base orchard, the weight gain per fruit was 6.1%, firmness increased by 0.6%, soluble solids increased by 3.2%, titratable acid increased by 2.2%, and the sugar-acid ratio decreased by 1.0%; in the Nanhesu orchard, the weight gain per fruit was 9.5%, firmness increased by 0.2%, soluble solids increased by 4.0%, titratable acid increased by 14.3%, and the sugar-acid ratio decreased by 9.0%. Apple bagging affects the internal quality of the fruit, reducing fruit weight, firmness, sugar, acid, and vitamin C content, and diluting the flavor. The growth protectant of this embodiment can increase the calcium content in the fruit. The calcium content in the peel of fruit from Jinyuan Garden increased by 12.4%, and the calcium content in the pulp increased by 49.8%; the calcium content in the peel of fruit from Huaibai Base Garden increased by 16.4%, and the calcium content in the pulp increased by 16.1%; the calcium content in the peel of fruit from Nanhesu Garden increased by 14.0%, and the calcium content in the pulp increased by 5.7%.

[0088] Table 3 Comparison of internal fruit quality

[0089]

[0090] The price of the growth protectant in this embodiment has been calculated in detail, and the cost per mu (a Chinese unit of area, approximately 0.165 acres) per year is only about 330 yuan. The specific cost calculation is as follows: One mu of land has approximately 100 fruit trees, with an annual fruit yield of approximately 2500 kg. The growth protectant dosage is calculated at 25 kg / mu per application. The unit price of the bag-free growth protectant is approximately 5 yuan / kg. Using a plant protection machine for spraying, the machine rental fee (including labor costs) is approximately 40 yuan / mu per application. The cost of spraying twice a year on one mu is 330 yuan (2 × 25 × 5 + 2 × 40). The cost of bagging is calculated as follows: Approximately 10,000 bags are needed per mu. The cost of manual bagging is approximately 0.24 yuan / bag, so the cost of manual bagging is 2400 yuan / mu (10000 × 0.24). Spraying the growth protectant in this embodiment can save 2070 yuan per mu compared to manual bagging, greatly improving economic efficiency and showing broad market prospects.

[0091] Example 2

[0092] This embodiment provides a calcium-containing growth protectant for fruit that does not require bagging, which is formulated with the following mass ratio: 10 parts monodisperse micro-nano calcium carbonate filter cake, 0.4 parts ethoxylated modified polytrisiloxane, 0.05 parts polyvinyl acetate emulsion, 0.9 parts glycerol, 0.1 parts modified casein, 0.05 parts enzyme, 0.1 parts mannitol, and 115 parts water.

[0093] The preparation method of the calcium-containing growth protectant for bagged fruit described in this embodiment is as follows: According to the above raw materials and mass proportions, 10 parts of monodisperse micro-nano calcium carbonate filter cake are placed in 15 parts of water. After stirring with a high-speed disperser at a stirring speed of 120 m / min for 15 min, 0.4 parts of ethoxylated modified polytrisiloxane, 0.05 parts of polyvinyl acetate emulsion, 0.9 parts of glycerol, 0.1 parts of modified casein, 0.05 parts of enzyme, 0.1 parts of mannitol and the remaining 100 parts of water are added according to the above formula. Stirring is continued at a stirring speed of 90 m / min for 30 min to obtain the growth protectant described in this embodiment. The solid content of calcium carbonate is about 5%. The preparation steps of the monodisperse micro / nano calcium carbonate filter cake differ from those in Example 1 in that: the digestion temperature in step S1 is 70℃, the aging time is 35 h, the solid content of the refined raw pulp during carbonation is 8%, the carbonation initiation temperature is 22℃, the CO2 content is 30%, and carbonation ends when the pH reaches 8.0~8.5. After carbonation, the calcium carbonate particles in the resulting mature pulp are characterized by microscopic morphology, and it can be observed that the calcium carbonate particles are nearly spherical with an average particle size of about 70 nm (see Figure 4); in step S2, during the grain surface reconstruction process, 0.5% sodium silicate, 1.5% aluminum chloride and 2% polyethylene glycol by dry weight of calcium carbonate are added, and the mixture is kept at 140℃ for 4 h.

[0094] The monodisperse micro / nano calcium carbonate filter cake obtained in this example was analyzed for composition, specific surface area, microstructure, and particle size using the same testing methods as in Example 1. The contents of harmful impurities such as cadmium, lead, barium, mercury, and arsenic in the obtained monodisperse micro / nano calcium carbonate were all less than 0.0002%, and the total content of harmful impurities was less than 200 ppm; the specific surface area was approximately 18.53 m². 2 / g; From the SEM image (see Figure 5), it can be clearly seen that the average particle size of the obtained monodisperse micro-nano calcium carbonate particles is about 110 nm, the particles are cubic, and the surface is flat and clean. The monodisperse micro-nano calcium carbonate filter cake was dispersed in water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 h. It could still be stably suspended (see Figure 17).

[0095] When spraying pears: Before the pears reach their full fruit enlargement stage, dilute the calcium-containing growth protectant for bagged fruit (calcium carbonate solid content approximately 2.5%) twice and spray it onto the surface of the pear fruit. After spraying, record the growth status of the entire pear tree by taking photos. Observe the tree regularly once a week thereafter. Spray 1-2 times during the pear ripening process. If there is continuous rainfall for more than 5 days, and the total rainfall reaches 250 mm or more, a re-spray is required after the rain. Ensure that there will be no rain for 24 hours before re-spraying.

[0096] Figure 6 shows the effect of the growth protectant prepared in this embodiment on pears. The protectant can spread quickly and adhere evenly to the fruit surface.

[0097] Spraying with the growth protectant prepared in this embodiment can effectively protect pears and significantly reduce fruit drop rate. Specific data are shown in Table 4. Note: Twenty pear trees were randomly selected from the same orchard for comparison.

[0098] Table 4 Comparison of effects on preventing pear fruit drop and insect infestation.

[0099]

[0100] The price of the product in this embodiment has been calculated in detail, with an annual cost of only about 700 yuan per mu (approximately 0.16 acres). The specific cost calculation is as follows: Approximately 100 trees are planted per mu, yielding about 3000 kg of fruit annually. The growth regulator is used at a rate of 100 kg / mu per application, and the growth protectant costs approximately 2.5 yuan / kg. Manual spraying is employed, with labor costs of approximately 100 yuan / mu per application. Therefore, the cost of spraying twice a year per mu is 700 yuan (2 × 100 × 2.5 + 2 × 100). The cost of bagging is calculated as follows: Approximately 10,000 bags are needed per mu, with a manual bagging cost of approximately 0.13 yuan / bag, resulting in a manual bagging cost of 1300 yuan / mu (10,000 × 0.13). Spraying the growth protectant in this embodiment saves 600 yuan per mu compared to manual bagging, improving economic efficiency and demonstrating a broad market prospect.

[0101] Example 3

[0102] This embodiment provides a calcium-containing growth protectant for bagged fruits, which is formulated from the following raw materials in parts by weight: 15 parts of monodisperse micro-nano calcium carbonate filter cake, 0.2 parts of ethoxylated modified polytrisiloxane, 0.8 parts of polyvinyl acetate emulsion, 0.2 parts of modified casein, 0.5 parts of enzyme, 0.9 parts of ribitol, and 45 parts of water.

[0103] The preparation method of the calcium-containing growth protectant for bagged fruit described in this embodiment is as follows: According to the above raw materials and mass proportions, 15 parts of monodisperse micro-nano calcium carbonate filter cake are placed in 20 parts of water. After stirring with a high-speed disperser at a stirring speed of 90 m / min for 30 min, 0.2 parts of ethoxylated modified polytrisiloxane, 0.8 parts of polyvinyl acetate emulsion, 0.2 parts of modified casein, 0.5 parts of enzyme, 0.9 parts of ribitol and the remaining 25 parts of water are added according to the above formula. Stirring is continued at a stirring speed of 110 m / min for 25 min to obtain the growth protectant described in this embodiment. The solid content of calcium carbonate is about 15%. The preparation steps of the monodisperse micro / nano calcium carbonate filter cake differ from those in Example 1 in that: the digestion temperature in step S1 is 80℃, the aging time is 30 h, the solid content of the refined raw pulp during carbonation is 5%, the carbonation initiation temperature is 30℃, the CO2 content is 20%, and carbonation ends when the pH reaches 8.0~9.0. After carbonation, the calcium carbonate particles in the resulting mature pulp are characterized by microscopic morphology, and it can be observed that the calcium carbonate particles are short chains with an average width of about 61 nm (see Figure 7); in step S2, during the crystal surface reconstruction process, 0.2% zinc sulfate, 0.5% sodium silicate, 1.4% polyethylene glycol and 0.6% hexadecyltrimethylammonium bromide by dry weight of calcium carbonate are added, and the mixture is kept at 180℃ for 2.5 h.

[0104] The monodisperse micro / nano calcium carbonate filter cake obtained in this example was analyzed for composition, specific surface area, microstructure, and particle size using the same testing methods as in Example 1. The contents of harmful impurities such as cadmium, lead, barium, mercury, and arsenic in the obtained monodisperse micro / nano calcium carbonate were all less than 0.0002%, and the total content of harmful impurities was less than 200 ppm; the specific surface area was approximately 17.26 m². 2 / g; From the SEM image (see Figure 8), it can be clearly seen that the average particle size of the obtained monodisperse micro-nano calcium carbonate particles is about 150 nm, the particles are cubic, and the surface is flat and clean. The monodisperse micro-nano calcium carbonate filter cake was dispersed in water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 h. It could still be stably suspended (see Figure 17).

[0105] When used for planting *Prunus cerasifera*: During the fruit enlargement period, choose a sunny day and use a regular sprayer to dilute the growth protectant 5 times (calcium carbonate solid content approximately 3%) and spray it onto the surface of the fruit. There is no need to avoid the leaves and branches. After spraying, take photos to record the overall growth of the *Prunus cerasifera* tree, and observe it regularly once a week thereafter. If there are more than 5 consecutive days of rainfall, with a total rainfall of 250 mm or more, a second spraying is required after the rain. If there has been no rainfall before harvesting, no additional spraying is necessary.

[0106] Figure 9 shows the effect of the growth protectant prepared in this embodiment on the plum. The growth protectant adheres evenly to the plum fruit and leaf surface, forming a thin and uniform protective film.

[0107] Figure 10 shows the ripening plums after spraying the growth protectant prepared in this embodiment onto their surface, and the ripening plums after bagging. Bagging blocks sunlight, resulting in less chlorophyll on the peel and a pale yellow color when ripe. Simultaneously, due to weak photosynthesis, the sugar, vitamin, and protein content in the fruit is correspondingly reduced, leading to poor sweetness and a lack of fruity aroma. In contrast, the plums sprayed with the growth protectant prepared in this embodiment are pale yellow-green when ripe, with a crisp, sweet taste and a rich fruity aroma.

[0108] Plums treated with the growth protectant prepared in this embodiment were free of fruit fly pests, while untreated natural fruit showed a greater number of fruit fly eggs and rotten cores (see Figure 11). Table 5 compares the fruit fly pest control effects of spraying with the growth protectant prepared in this embodiment with bagging and no treatment. The fruit fly control effect of the plums treated with the growth protectant is significantly higher than that of the untreated plums, and comparable to that of bagging. Note: 100 plums from 10 plum trees in the same orchard were randomly selected for comparison.

[0109] Table 5 Comparison of effects in controlling fruit fly pests

[0110]

[0111] The price of the product in this embodiment has been calculated in detail, with an annual cost of only about 950 yuan per mu (approximately 0.067 hectares). The specific cost calculation is as follows: Approximately 100 trees are planted per mu, yielding about 3000 jin (approximately 1500 kg) of fruit annually. The growth regulator is applied at a rate of 50 kg / mu per application, and the growth protectant costs approximately 7.5 yuan / kg. Manual spraying is used, with a labor cost of approximately 100 yuan / mu per application. Therefore, the cost of spraying twice a year per mu is 950 yuan (2 × 50 × 7.5 + 2 × 100). The cost of bagging is calculated as follows: Approximately 20,000 bags are needed per mu, with a manual bagging cost of approximately 0.1 yuan / bag, resulting in a manual bagging cost of 2000 yuan / mu (20000 × 0.1). Spraying the growth protectant in this embodiment saves 1050 yuan per mu compared to manual bagging, improving economic efficiency and demonstrating a broad market prospect.

[0112] Example 4

[0113] This embodiment provides a calcium-containing growth protectant for bagged fruits, which is formulated from the following raw materials in parts by weight: 5 parts monodisperse micro-nano calcium carbonate filter cake, 0.3 parts ethoxylated modified polytrisiloxane, 0.2 parts polyvinyl acetate emulsion, 0.1 parts modified casein, 0.2 parts enzyme, 0.1 parts lactitol, and 25 parts water.

[0114] The preparation method of the calcium-containing growth protectant for bagged fruit described in this embodiment is as follows: According to the above raw materials and mass proportions, 8 parts of monodisperse micro-nano calcium carbonate filter cake are placed in 8 parts of water. After stirring with a high-speed disperser at a stirring speed of 110 m / min for 20 min, 0.3 parts of ethoxylated modified polytrisiloxane, 0.2 parts of polyvinyl acetate emulsion, 0.1 parts of modified casein, 0.2 parts of enzyme, 0.1 parts of lactitol and the remaining 17 parts of water are added according to the above formula. Stirring is continued at a stirring speed of 80 m / min for 30 min to obtain the growth protectant described in this embodiment. The solid content of calcium carbonate is about 10%. The preparation steps of the monodisperse micro / nano calcium carbonate filter cake differ from those in Example 1 in that the digestion temperature in step S1 is 60℃, the aging time is 40 h, the solid content of the refined raw pulp during carbonation is 12%, the carbonation initiation temperature is 10℃, the CO2 content is 35%, and carbonation ends when the pH reaches 8.0~8.5. After carbonation, the calcium carbonate particles in the resulting mature pulp are characterized by microscopic morphology, and it can be observed that the calcium carbonate particles are nearly spherical with an average particle size of about 53 nm (see Figure 12). In step S2, during the crystal surface reconstruction process, 1% sodium silicate, 1.5% polyvinyl alcohol, and 1.5% sodium dodecylbenzenesulfonate by dry weight of calcium carbonate are added, and the mixture is kept at 200℃ for 1 h.

[0115] The monodisperse micro / nano calcium carbonate filter cake obtained in this example was analyzed for composition, specific surface area, microstructure, and particle size using the same testing methods as in Example 1. The contents of harmful impurities such as cadmium, lead, barium, mercury, and arsenic in the obtained monodisperse micro / nano calcium carbonate were all less than 0.0002%, and the total content of harmful impurities was less than 200 ppm; the specific surface area was approximately 18.24 m². 2 / g; From the SEM image (see Figure 13), it can be clearly seen that the average particle size of the obtained monodisperse micro-nano calcium carbonate particles is about 120 nm, the particles are cubic, and the surface is flat and clean. The monodisperse micro-nano calcium carbonate filter cake was dispersed in water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 h. It could still be stably suspended (see Figure 17).

[0116] When used for guava cultivation: One month after fruit set, when the young fruit reaches a longitudinal diameter of 3-4 cm and begins to droop, choose a sunny day and use a regular sprayer to spray the guava fruit surface with a 10-fold diluted growth protectant (calcium carbonate solid content approximately 1%). There is no need to avoid the leaves and branches. After spraying, record the overall growth of the guava tree by taking photos, and observe it regularly every week thereafter. If there are more than 5 consecutive days of rainfall, with a total rainfall of 250 mm or more, a second spraying is required after the rain. Before the fruit matures, a second spraying is generally done in mid-August each year.

[0117] Guava trees sprayed with the growth protectant prepared in this embodiment showed no fruit fly infestation, while untreated guava trees exhibited a higher number of fruit fly eggs and rotten cores. Table 6 compares the fruit fly control effects of spraying the growth protectant prepared in this embodiment with those of bagging and untreated guava. The fruit fly control effect of spraying the growth protectant prepared in this embodiment was significantly higher than that of untreated guava, and roughly equivalent to that of bagging. Note: 400 guavas (20 guavas per tree) were randomly selected from 20 guava trees in the same orchard for comparison.

[0118] Table 6 Comparison of effects on control of fruit fly pests

[0119]

[0120] The price of the product in this embodiment has been calculated in detail, with an annual cost of only about 700 yuan per mu (approximately 0.16 acres). The specific cost calculation is as follows: the annual fruit yield per mu is about 3000 kg; the dosage of the growth agent is 50 kg / mu per application; the unit price of the growth protectant is about 5 yuan / kg; manual spraying is used, with a labor cost of about 100 yuan / mu per application; the cost of spraying twice a year per mu is 700 yuan (2×50×5+2×100); the cost of bagging is calculated as follows: about 8000 bags are needed per mu; the cost of manual bagging is about 0.16 yuan / bag; therefore, the cost of manual bagging is 1280 yuan / mu (8000×0.16). Compared with manual bagging, spraying the growth protectant of this embodiment can save 580 yuan per mu, improving economic efficiency and showing broad market prospects.

[0121] Example 5

[0122] This embodiment provides a calcium-containing growth protectant for bagged fruits, which is formulated from the following raw materials in parts by weight: 20 parts of monodisperse micro-nano calcium carbonate filter cake, 0.5 parts of ethoxylated modified polytrisiloxane, 0.9 parts of polyvinyl acetate emulsion, 0.2 parts of glycerol, 0.8 parts of modified casein, 0.2 parts of enzyme, 0.1 parts of sorbitol, and 180 parts of water.

[0123] The preparation method of the calcium-containing growth protectant for bagged fruit described in this embodiment is as follows: According to the above raw materials and mass proportions, 3 parts of monodisperse micro-nano calcium carbonate filter cake are placed in 30 parts of water. After stirring with a high-speed disperser at a stirring speed of 80 m / min for 40 min, 0.5 parts of ethoxylated modified polytrisiloxane, 0.9 parts of polyvinyl acetate emulsion, 0.2 parts of glycerol, 0.8 parts of modified casein, 0.2 parts of enzyme, 0.1 parts of sorbitol and the remaining 150 parts of water are added according to the above formula. Stirring is continued at a stirring speed of 80 m / min for 30 min to obtain the growth protectant described in this embodiment, with a calcium carbonate solid content of approximately 6%.

[0124] The preparation steps of the monodisperse micro / nano calcium carbonate filter cake differ from those in Example 1 in that: the digestion temperature in step S1 is 50℃, the aging time is 48 h, the solid content of the refined raw pulp during carbonation is 10%, the carbonation initiation temperature is 25℃, the CO2 content is 33%, and carbonation ends when the pH reaches 7.5~8.5. After carbonation, the calcium carbonate particles in the resulting mature pulp are characterized by microscopic morphology, and it can be observed that the calcium carbonate particles are chain-like with an average width of about 68 nm (see Figure 14); in step S2, during the crystal surface reconstruction process, 1.5% sodium chloride, 0.5% sodium silicate, 1% zinc sulfate, 0.5% ethanol, and 0.5% disodium ethylenediaminetetraacetate by dry weight of calcium carbonate are added, and the mixture is kept at 190℃ for 3 h.

[0125] The monodisperse micro / nano calcium carbonate filter cake obtained in this example was analyzed for composition, specific surface area, microstructure, and particle size using the same testing methods as in Example 1. The contents of harmful impurities such as cadmium, lead, barium, mercury, and arsenic in the obtained monodisperse micro / nano calcium carbonate were all less than 0.0002%, and the total content of harmful impurities was less than 200 ppm; the specific surface area was approximately 16.92 m². 2 / g; From the SEM image (see Figure 15), it can be clearly seen that the average particle size of the obtained monodisperse micro-nano calcium carbonate particles is about 195 nm, the particles are cubic, and the surface is flat and clean. The monodisperse micro-nano calcium carbonate filter cake was dispersed in water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 h. It could still be stably suspended (see Figure 17).

[0126] When used for pomelo cultivation: When the fruit diameter reaches 3-5 cm, choose a sunny day and use a regular sprayer to dilute the growth protectant 3 times (calcium carbonate solid content is approximately 2%) and spray it directly onto the surface of the pomelo fruit, without specifically avoiding the leaves and branches. After spraying, take photos to record the growth status of the entire pomelo tree, and observe it regularly once a week thereafter. If there is continuous rainfall for more than 5 days, and the total rainfall reaches 250 mm or more, a second spray is required after the rain. If there has been no rainfall before harvest, no additional spraying is necessary.

[0127] Pomelos sprayed with the growth protectant prepared in this embodiment were virtually free of pests such as fruit borers and codling moths. Untreated, naturally grown pomelos showed more insect damage and cracking, and a greater amount of dried flesh near the stem end. Table 7 compares the pest and crack prevention effects of spraying with the growth protectant prepared in this embodiment with those of bagging and untreated pomelos. The pest and crack prevention effects of the pomelos sprayed with the growth protectant are significantly higher than those without treatment, and roughly equivalent to those of bagging. Note: 200 pomelos from the same orchard were randomly selected for comparison.

[0128] Table 7 Comparison of Pest Control and Fruit Drop Prevention Effects

[0129]

[0130] The price of the product in this embodiment has been calculated in detail, with an annual cost of only about 600 yuan per mu (approximately 0.16 acres). The specific cost calculation is as follows: the annual fruit yield per mu is about 5000 kg; the dosage of the growth agent is 100 kg / mu per application; the unit price of the growth protectant is about 2 yuan / kg; manual spraying is used, with a labor cost of about 100 yuan / mu per application; the cost of spraying twice a year per mu is 700 yuan (2×100×2+2×100); the cost of bagging is calculated as follows: about 5000 bags are needed per mu; the cost of manual bagging is about 0.3 yuan / bag; therefore, the cost of manual bagging is 1500 yuan / mu (5000×0.3). Compared with manual bagging, spraying the growth protectant of this embodiment can save 900 yuan per mu, improving economic efficiency and showing broad market prospects.

[0131] Comparative Example 1

[0132] Comparative Example 1 has the same formulation as Example 1, except that no inorganic grain surface reconstruction agent was added in the preparation method of calcium carbonate. The microstructure of the obtained product is shown in Figure 16.

[0133] In Comparative Example 1, because no inorganic crystal surface remodeling agent was added, the calcium carbonate crystal surface was rough, and the dispersion between particles was relatively poor. This resulted in the formation of bonds between particles, leading to reduced dispersion stability in water, as shown in Figure 17. Furthermore, due to the hard agglomeration of particles, the film formed on the apple fruit surface was uneven (see Figure 18 left), failing to achieve good protection. As a result, the apple fruit exhibited uneven coloring after ripening (see Figure 18 right).

[0134] Comparative Example 2

[0135] Comparative Example 2 has the same formulation as Example 2, except that no organic grain surface remodeling agent was added in the preparation method of calcium carbonate. The microstructure of the obtained product is shown in Figure 19.

[0136] In Comparative Example 2, because no organic crystal surface remodeling agent was added, the calcium carbonate crystal surface was clean, but the dispersibility between particles was still relatively poor, and the particles formed bonds, resulting in reduced dispersion stability in water, as shown in Figure 17. Furthermore, due to the hard agglomeration of particles, the film formed on the pear fruit surface was uneven (see Figure 20), failing to achieve good protection, and many spots appeared on the fruit surface.

[0137] Comparative Example 3

[0138] The calcium carbonate preparation method of Comparative Example 3 is the same as that of Example 3, except that ethoxylated modified polytrisiloxane and polyvinyl acetate emulsion modified casein are not added to the formulation.

[0139] In Comparative Example 3, because no adjuvants were added, the growth protectant did not penetrate the surface of the plum fruit during the spraying process, resulting in the failure of the growth protectant to be sprayed successfully, as shown in Figure 21.

[0140] Comparative Example 4

[0141] Comparative Example 4 has the same formulation as Example 1, except that the calcium carbonate preparation method does not involve pressure filtration to obtain a monodisperse calcium carbonate filter cake with a special morphology. Instead, the slurry obtained after the crystal surface is reconstructed is directly prepared according to the proportions described in Example 1.

[0142] Comparative Example 4, because the soluble ions in the slurry were not removed by pressure filtration, was sprayed on the apple fruit surface. The harmful ions affected the fruit surface, and many spots appeared on the fruit surface after ripening, as shown in Figure 22.

[0143] Comparative Example 5

[0144] Comparative Example 5 has the same formulation as Example 2, except that the preparation method of the growth protectant is not carried out in a two-step dispersion step. Instead, 10 parts of monodisperse micro-nano calcium carbonate filter cake are directly added to 115 parts of water and stirred for 15 min at a stirring speed of 120 m / min using a high-speed disperser. After stirring evenly, ethoxylated modified polytrisiloxane, polyvinyl acetate emulsion, glycerol, modified casein, enzyme and mannitol are added according to the ingredient ratio, and stirring is continued at a stirring speed of 100 m / min for 15 min.

[0145] Comparative Example 5, lacking a high-concentration stirring step, resulted in poor calcium carbonate dispersion. When sprayed on the pear fruit surface, the slurry could not form a film well on the fruit surface, exhibiting local variations in concentration and accumulating more at the fruit stem, leading to numerous spots on the fruit surface after ripening and a higher fruit drop rate, as shown in Figure 23.

[0146] Comparative Example 6

[0147] The preparation method of calcium carbonate in Comparative Example 6 is the same as that in Example 1, except that modified casein, enzymes and maltitol are not added to the formula.

[0148] Comparative Example 6, due to the absence of added additives, showed poor calcium supplementation and pest control effects when used for apple bagging-free cultivation. Compared with the effect of spraying Example 1, the calcium content of the fruit pulp in Jinyuan Garden decreased by 19.5%, the calcium content of the fruit pulp in Huaibai Base Garden decreased by 6.7%, and the calcium content of the fruit pulp in Nanhesu Garden decreased by 4.5%.

[0149] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A calcium-containing growth protectant for fruit that does not require bagging, comprising, by weight parts: The composition includes 1-20 parts of monodisperse micro / nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxylated modified polytrisiloxane, 0-0.8 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.8 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water; wherein the polyvinyl acetate emulsion and glycerol are not simultaneously zero. The monodisperse micro / nano calcium carbonate filter cake has a moisture content of 35%–40%, the average particle size of the calcium carbonate particles is between 50 and 200 nm, the particles with a diameter greater than 200 nm are less than 5%, and the specific surface area is less than 20 m². 2 / g; and the monodisperse micro / nano calcium carbonate filter cake is stirred and dispersed in aqueous solution without the addition of any chemical dispersant, and remains stably suspended.

2. The calcium-containing growth protectant for bagged fruit according to claim 1, wherein the raw materials, calculated by weight proportions, include: The mixture comprises 1-20 parts of monodisperse micro / nano calcium carbonate filter cake, 0.05-0.5 parts of ethoxylated modified polytrisiloxane, 0.02-0.9 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.5 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water. The monodisperse micro / nano calcium carbonate filter cake is dispersed in water to obtain a suspension. When the solid content of the suspension is 5%-30%, it can be stably suspended for more than 14 hours.

3. A calcium-containing growth protectant for bagged-free fruits according to claim 1, wherein, The mass of monodisperse micro / nano calcium carbonate filter cake is 15 to 75 times that of ethoxylated modified polytrisiloxane.

4. A calcium-containing growth protectant for bagged-free fruits according to claim 3, wherein, The mass of monodisperse micro / nano calcium carbonate filter cake is 15 to 40 times that of ethoxylated modified polytrisiloxane.

5. A calcium-containing growth protectant for bagged-free fruits according to claim 1, wherein, The mass of water is 3 to 12 times that of monodisperse micro / nano calcium carbonate filter cake.

6. A calcium-containing growth protectant for bagged fruit according to claim 1, wherein, The mass of monodisperse micro / nano calcium carbonate filter cake is 15 to 200 times that of polyvinyl acetate emulsion.

7. A calcium-containing growth protectant for bagged fruit according to claim 6, characterized in that, The mass of monodisperse micro / nano calcium carbonate filter cake is 18.75 to 50 times that of polyvinyl acetate emulsion.

8. A calcium-containing growth protectant for bagged fruit according to claim 1, wherein, The mass of monodisperse micro / nano calcium carbonate filter cake is 25 to 100 times that of modified casein.

9. A calcium-containing growth protectant for bagged-free fruits according to claim 1, wherein, The mass of monodisperse micro / nano calcium carbonate filter cake is 25 to 100 times that of enzymes.

10. A calcium-containing growth protectant for bagged fruit according to claim 1, wherein, The mass of monodisperse micro / nano calcium carbonate filter cake is 15 to 200 times that of sugar alcohol.

11. A calcium-containing growth protectant for bagged-free fruits according to claim 1, wherein, The method for preparing the monodisperse micro / nano calcium carbonate filter cake includes the following steps: S1. Calcium carbonate slurry is prepared using a process including calcination, digestion, and carbonation. S2. Add inorganic salt grain surface remodeling agent and organic grain surface remodeling agent to the calcium carbonate slurry obtained in S1, and then keep it at 140~200℃ for 1.0~4.0 h to obtain calcium carbonate suspension; S3. The calcium carbonate suspension obtained in S2 is dehydrated by hydraulic filtration to obtain a calcium carbonate filter cake. The moisture content of the filter cake is controlled between 35% and 40%, which is a monodisperse micro-nano calcium carbonate filter cake.

12. A calcium-containing growth protectant for bagged-free fruits according to claim 11, wherein, The calcination process is as follows: limestone with uniform grain size and a harmful heavy metal content of less than 400 ppm is selected as raw material and calcined to obtain quicklime. The activity of quicklime is in the range of 250-300 mL. The digestion process is as follows: the quicklime obtained by calcination is digested in hot water at 50-90 ℃ to obtain lime milk, which is then aged for 24-48 h, filtered to remove impurities, and refined raw pulp is obtained. The carbonation process is as follows: water is added to the refined raw pulp to adjust the solid content to 5% to 12%, and then carbonation is carried out. The initial carbonation temperature is 10 to 30℃, the CO2 content is 20% to 40%, and carbonation is carried out until the pH of the pulp reaches 7.5 to 9.

0. The carbonation is then stopped to obtain calcium carbonate cooked pulp.

13. A calcium-containing growth protectant for bagged fruit according to claim 11, wherein, The inorganic salt grain surface remodeling agent is one or more of sodium silicate, sodium chloride, aluminum chloride, and zinc sulfate, and the amount used is 0.5% to 3% of the dry weight of calcium carbonate.

14. A calcium-containing growth protectant for bagged fruit according to claim 11, wherein, The organic grain surface remodeling agent is one or more of ethanol, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and disodium ethylenediaminetetraacetate, and the amount used is 1% to 5% of the dry weight of calcium carbonate.

15. A calcium-containing growth protectant for bagged-free fruits according to claim 1, wherein, The sugar alcohols include one or more of xylitol, ribitol, mannitol, sorbitol, maltitol, erythritol, and lactitol; the enzymes are commercially available agricultural enzymes.

16. A method for preparing the calcium-containing growth protectant for bagged fruit according to any one of claims 1 to 15, comprising the following steps: (1) According to the raw materials and their mass fractions, prepare 1-20 parts of monodisperse micro-nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxy-modified polytrisiloxane, 0-0.8 parts of polyvinyl acetate emulsion, 0-0.9 parts of glycerol, 0.01-0.8 parts of modified casein, 0.01-0.8 parts of enzyme, 0.01-0.9 parts of sugar alcohol, and 5-180 parts of water, and the polyvinyl acetate emulsion and glycerol are not simultaneously zero; (2) Place the monodisperse micro-nano calcium carbonate filter cake in a portion of water at a temperature of 5~30℃ and disperse it in a high-speed disperser at a linear velocity of 80~120 m / min for 15~40 min. (3) After the stirring in step (2) is completed, add other raw materials and the remaining water, and continue to disperse in a high-speed disperser at a linear speed of 80~120 m / min for 15~30 min to obtain the calcium-containing growth protectant for the bag-free fruit.

17. The method for preparing the calcium-containing growth protectant for bagged fruit according to claim 16, wherein in step (2), the amount of water used to disperse the monodisperse micro-nano calcium carbonate filter cake is 1 to 2 times the weight of the monodisperse micro-nano calcium carbonate filter cake.

18. The method of applying the calcium-containing growth protectant for bagless fruits according to any one of claims 1 to 17, wherein when used to prevent fruit cracking and improve coloring effect, the calcium-containing growth protectant for bagless fruits is diluted with water to a calcium carbonate solid content of 0.5% to 2% before spraying; when used to prevent pests and reduce fruit drop, the calcium-containing growth protectant for bagless fruits is diluted with water to a calcium carbonate solid content of 1% to 3% before spraying.

19. The method of applying the calcium-containing growth protectant for bagged fruit according to claim 18, in dry weather without rain, the calcium-containing growth protectant is diluted and sprayed on the surface of the fruit without needing to avoid branches and leaves. It needs to be sprayed 2 to 4 times during the fruit ripening process. If there is more than 5 days of rainfall within 24 hours after spraying, and the total rainfall reaches 250 mm or more, it is necessary to spray again after the rain.

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