Calcium-containing growth protective agent for bag-free fruits and preparation method and application thereof

Abstract

The application discloses a calcium-containing growth protective agent for bag-free fruits, which is prepared from the following raw materials in parts by mass: 1-20 parts of monodisperse micro-nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxylated polysiloxane, 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 the glycerol cannot be zero at the same time. The above raw materials are mixed in two steps in a certain order, and a new calcium-containing growth protective agent is obtained after stirring and dispersing. After dilution with water to a solid content of calcium carbonate of 0.5-6%, the growth protective agent is used for bag-free planting of fruits. The growth protective agent is non-toxic, and is sprayed on the surface of fruit crops when used. The growth protective agent has good physical insect prevention effect and repellent effect, can significantly improve the disease resistance and insect prevention capacity of fruits, reduces the number of diseased fruits and insect-infested fruits, does not affect the transmission of visible light, and can significantly improve the taste and quality of the fruits compared with the bagged planting fruits.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of plant growth agents, and particularly relates to a calcium-containing growth protective agent for bag-free fruits and application thereof in bag-free planting of fruits. BACKGROUND

[0002] Due to the great threat of pests, current fruit planting generally uses paper bags or plastic bags to cover fruits for bagging planting. This physical protection method can effectively prevent insects from harming fruits and is widely used. However, it also greatly increases the labor cost in fruit planting. Bagging also affects the photosynthesis of fruits, resulting in a decrease in fruit taste and nutritional value. Therefore, there is an urgent need for an effective bag-free fruit planting method.

[0003] At present, there are various plant growth agents and protective agents on the market, such as gibberellic acid, fresh amine ester, anti-drop element, benzylaminopurine, etc. for yield increase; amino acid-containing water-soluble fertilizer for cold resistance; lime milk whitening agent for high temperature resistance, etc. The use of these plant growth agents can promote growth or provide protection during the growth of crops, fruits, and vegetables. However, the preparation methods of some of these plant growth agents are complex, such as the production of gibberellic acid for yield increase, which requires multiple processes such as strain culture, fermentation, extraction, and purification. Some components are expensive, such as amino acid-containing water-soluble fertilizer. Some products often have problems such as sedimentation and caking during use, such as lime milk whitening agent. Even some products can cause soil environmental damage. More importantly, these growth agents generally have a single function, emphasizing production promotion but having weak protection against pests and diseases, and cannot replace fruit bagging. Therefore, there is an urgent need to develop a plant protection product that can effectively protect fruits from pests and diseases, provide certain nutritional support for plant growth, and is low in cost. SUMMARY

[0004] In view of the above deficiencies of the prior art, the present application provides a calcium-containing growth protective agent for bag-free fruits. The calcium-containing growth protective agent is non-toxic and can be directly sprayed onto the surface of fruit crops, replacing traditional fruit bagging for bag-free fruit planting. It has good physical insect prevention and repellent effects, can significantly improve the disease resistance and insect resistance of fruits, and reduce diseased and insect-damaged fruits.

[0005] The technical solution adopted by the present application to achieve the above-mentioned purposes is as follows:

[0006] The calcium-containing growth protective agent for bag-free fruits comprises, in parts by mass, 1-20 parts of monodisperse micro-nano calcium carbonate filter cake, 0.01-0.9 parts of ethoxylated modified polysiloxane, 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 the glycerol are not zero at the same time.

[0007] Preferably, the calcium-containing growth protective agent for bag-free fruits comprises, in parts by mass, 1-20 parts of monodisperse micro-nano calcium carbonate filter cake, 0.05-0.5 parts of ethoxylated modified polysiloxane, 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.

[0008] Further, the mass of the monodisperse micro-nano calcium carbonate filter cake is 15-75 times, preferably 15-40 times, the mass of the ethoxylated modified polysiloxane.

[0009] Further, the mass of the water is 3-12 times, preferably 5-9 times, the mass of the monodisperse micro-nano calcium carbonate filter cake.

[0010] Further, the mass of the monodisperse micro-nano calcium carbonate filter cake is 15-200 times, preferably 18.75-50 times, the mass of the polyvinyl acetate emulsion.

[0011] Further, the mass of the monodisperse micro-nano calcium carbonate filter cake is 25-100 times the mass of the modified casein.

[0012] Further, the mass of the monodisperse micro-nano calcium carbonate filter cake is preferably 25-100 times the mass of the enzyme.

[0013] Further, the mass of the monodisperse micro-nano calcium carbonate filter cake is 15-200 times, preferably 50-100 times, the mass of the sugar alcohol.

[0014] According to the above scheme, the monodisperse micro-nano calcium carbonate filter cake has the following characteristics: the filter cake has a water content of 35-40%, the calcium carbonate particles have a cubic or near-spherical morphology, the average particle size is 50-200 nm, and the number of particles with a particle size greater than 200 nm is less than 5%; the particle surface is clean and in a monodisperse state, has a small surface energy, and has a specific surface area of less than 20 m 2 / g, preferably 16-18 m 2ppm; the monodisperse micro-nano calcium carbonate filter cake can be stirred and dispersed in an aqueous solution without adding any chemical dispersant and can be 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%, the suspension can be stably suspended for more than 2 hours; when the solid content of the suspension is 5% to 30%, the suspension can be stably suspended for more than 14 hours.

[0015] According to the above scheme, the preparation method of the monodisperse micro-nano calcium carbonate filter cake comprises the following steps:

[0016] S1. A calcium carbonate slurry is prepared by calcination, digestion, carbonization and the like. In the calcination process, limestone with uniform grain size and harmful heavy metal content (such as cadmium, lead and chromium) less than 400 ppm is selected as raw material, and a calcination temperature matching the grain size is used to obtain lime with ideal activity, the activity of the lime is between 250 mL and 300 mL (4 mol / L HCl, 40±1℃, 10 min), and the uniformity and consistency are good. In the digestion process, the lime obtained by the above calcination is digested in hot water at 50-90℃ to obtain lime milk. In the storage and impurity removal process, the lime milk obtained by digestion is stored for 24-48 hours, and then filtered and impurities are removed to obtain refined lime slurry. In the carbonization process, the refined lime slurry is added with water to adjust the solid content to 5%-12%, and then carbonization is carried out, the initial carbonization temperature is 10-30℃, the CO2 content is 20%-40%, the carbonization is stopped when the slurry pH reaches 7.5-9.0, and the calcium carbonate slurry is obtained.

[0017] The calcium carbonate particles in the calcium carbonate slurry have a near-spherical or chain-like morphology, the average particle size of the near-spherical particles is 30-100 nm, and the average width (lateral size) of the chain-like particles is 30-100 nm.

[0018] S2. Inorganic salt grain surface restructuring agents and organic grain surface restructuring agents are added to the calcium carbonate slurry obtained in S1, and then the mixture is kept at 140-200℃ for 1.0-4.0 hours to obtain a calcium carbonate suspension. The inorganic grain surface restructuring agents are one or more of sodium silicate, sodium chloride, aluminum chloride, zinc sulfate and the like, and the amount used is 0.5%-3% of the dry mass of the calcium carbonate. The organic grain surface restructuring agents are one or more of ethanol, polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol, sodium dodecylbenzenesulfonate, cetyltrimethylammonium bromide, sodium dodecyl sulfate, and disodium ethylenediaminetetraacetate, and the amount used is 1%-5% of the dry mass of the calcium carbonate.

[0019] S3. The calcium carbonate suspension obtained in S2 is filtered and dewatered to obtain a calcium carbonate filter cake, the moisture content of which is controlled to be between 35% and 40%, i.e. a monodisperse micro-nano calcium carbonate filter cake. At this time, the calcium carbonate particles have a cubic or near-spherical morphology, the average particle size is between 50 and 200 nm, the content of particles with a particle size greater than 200 nm is less than 5%, the particle surface is clean and in a monodisperse state, the specific surface area is less than 20 m 2 / g, the content of harmful metal elements such as cadmium in the calcium carbonate is less than 200 ppm, the calcium carbonate can be dispersed in an aqueous solution without adding any chemical dispersant and can be stably suspended after stirring.

[0020] According to the above scheme, the sugar alcohol includes one or more of xylitol, ribitol, mannitol, sorbitol, maltitol, erythritol, and lactitol.

[0021] According to the above scheme, the modified casein is a milky white viscous liquid, the solid content is 15% to 25%, the viscosity (20°C) is greater than 100 mPa·s, and the pH value (10% aqueous solution) is 7 to 8.

[0022] According to the above scheme, the ferment is a commercially available agricultural ferment, and the ferment contains agricultural biological inoculants, polysaccharides, amino acids, and other components.

[0023] The preparation method of the calcium-containing growth protection agent for the bag-free fruit includes the following steps:

[0024] (1) According to the mass ratio of each raw material of the calcium-containing growth protection agent and the mass parts thereof, 1 to 20 parts of the monodisperse micro-nano calcium carbonate filter cake, 0.01 to 0.9 parts of the ethoxylated modified polysiloxane, 0 to 0.8 parts of the polyvinyl acetate emulsion, 0 to 0.9 parts of the glycerol, 0.01 to 0.8 parts of the modified casein, 0.01 to 0.8 parts of the ferment, 0.01 to 0.9 parts of the sugar alcohol, and 5 to 180 parts of the water are prepared;

[0025] (2) The monodisperse micro-nano calcium carbonate filter cake is placed in a small amount of water (here, the weight of the "small amount of water" is 1 to 2 times the weight of the monodisperse micro-nano calcium carbonate filter cake in the formula) at a temperature of 5 to 30°C, and is dispersed in a high-speed dispersing machine at a linear speed of 80 to 120 m / min at room temperature for 15 to 40 min;

[0026] (3) After the stirring in step (2) is completed, the remaining other raw materials and the remaining amount of water are added, and the dispersion is continued in the high-speed dispersing machine at a linear speed of 80 to 120 m / min for 15 to 30 min, to obtain the calcium-containing growth protection agent for the bag-free fruit according to the present application.

[0027] The calcium-containing growth protection agent for bag-free fruit can be further diluted according to different application scenarios during use. When used for preventing fruit cracking and improving coloring effect, the agent is diluted with water to a solid content of calcium carbonate of 0.5% to 2% and then sprayed; when used for preventing insect pests and reducing fruit drop, the agent is diluted with water to a solid content of calcium carbonate of 1% to 3% and then sprayed.

[0028] According to the above scheme, the bag-free fruit of the application includes apples, oranges, pears, plums, mangoes, cherries, grapes, dragon fruits, oranges, loquats, apricots, kiwifruits, grapefruits, pomegranates, green dates, guavas, peaches, etc.

[0029] The calcium-containing growth protection agent of the application can be used for bag-free fruit planting, and the application method is as follows: in dry weather without rain, the agent is diluted and sprayed on the surface of the fruit, without the need to specially avoid branches and leaves, and 2 to 4 times of spraying are required during the fruit ripening process according to the type of fruit; when it rains for more than 5 days within 24 hours after spraying, and the total rainfall reaches 250 mm or more, the agent needs to be sprayed again after the rain.

[0030] The application selects limestone with uniform crystal grain size and harmful heavy metal content (such as cadmium, lead and chromium) less than 400 ppm as a raw material for preparing monodisperse micro-nano calcium carbonate filter cake, then adopts a calcination temperature matching the crystal grain size to obtain quicklime with moderate and uniform activity, and then carbonizes the quicklime to obtain calcium carbonate slurry. The limestone with uniform crystal grain size adjusts the activity of lime through limestone calcination process, avoiding partial underfiring and partial overfiring caused by spotted crystal grains; the lime with good uniformity and moderate activity is conducive to the control of digestion reaction, obtaining uniform lime milk with controllable properties, and then realizing the control of the later carbonization process, thereby obtaining calcium carbonate slurry with expected particle size and crystal morphology. The harmful heavy metal content (such as cadmium, lead and chromium) in the limestone is less than 400 ppm, which can ensure that the harmful heavy metal content in the prepared monodisperse micro-nano calcium carbonate filter cake is less than 200 ppm.

[0031] After the carbonization is finished, there is a process step of grain surface reconstruction, which is by adding inorganic surface reconstruction agent and organic surface reconstruction agent and keeping at a certain temperature, promoting grain surface reconstruction, making the crystal more complete, the particle surface more smooth, reducing the surface energy, thereby facilitating dispersion. The role of the inorganic surface reconstruction agent is to promote crystal growth, repair defects, and make the crystal more complete; the role of the organic surface reconstruction agent is to adjust the surface potential of the particles, control the mutual repulsion of the grains in water, and avoid adhesion during the crystal repair process. The present application controls the average particle size of calcium carbonate particles to be 50-200 nm by controlling the grain surface reconstruction temperature and time, and the particles are in a high monodisperse state. The calcium carbonate particles in this form can ensure the transmission of visible light, so they do not affect the photosynthesis of the fruit and the surface coloring. At the same time, they can effectively absorb ultraviolet light that is harmful to plants (for example, the calcium-containing growth protection agent described in the present application is diluted to a solid content of 2% calcium carbonate, and the absorption of ultraviolet light can reach more than 85%, and the absorption of visible light is less than 15%). The monodisperse micro-nano calcium carbonate slurry obtained by grain surface reconstruction is then filtered or centrifuged to obtain monodisperse micro-nano calcium carbonate filter cake of the desired particle size. The filter press and centrifuge can remove excess water to form monodisperse micro-nano calcium carbonate filter cake, which is beneficial to the processing and transportation of calcium carbonate. At the same time, it also rapidly reduces other soluble ions present in the solution during the production process, achieving the effect of not affecting and interfering with the use and effectiveness of the calcium-containing growth protection agent of the present application.

[0032] On the basis of the above, the present application uses the monodisperse micro-nano calcium carbonate filter cake as the main raw material, which is compounded with other raw materials and dispersed in clean water to obtain the calcium-containing growth protection agent for bag-free fruits of the present application. The monodisperse micro-nano calcium carbonate filter cake maintains 35%-40% moisture, which maintains the water film and double-layer structure between the calcium carbonate solid particles, can maximize the surface state and repulsion of the calcium carbonate particles without being destroyed, and can not produce agglomeration, so that it can be quickly re-dispersed in the aqueous solution during the auxiliary stirring of the disperser and remain stable suspension.

[0033] The calcium-containing growth protection agent for bag-free fruits of the present application can quickly form a light white protective film on the surface of the fruit when sprayed on the surface of the fruit, effectively resisting pests and diseases; due to the special particle size and dispersibility design of calcium carbonate, the protective film does not affect the transmission of visible light, so it does not affect the photosynthesis of the fruit; the present application utilizes the characteristics of ultraviolet light absorption and infrared radiation of calcium carbonate, combined with the particle size design of the present application, can effectively reduce the temperature of the fruit, and form effective physical and optical protection.

[0034] The present application adds modified casein as a film-forming agent with good air permeability and strong adhesion, and its main component casein can promote the growth and development of plants, can improve the fertilizer efficiency and yield, and is beneficial to the late yield increase of crops.

[0035] The present application can effectively prevent and treat insect pests by adding the enzyme; in addition, the polysaccharide, amino acid and other components contained in the present application can improve the level of plant absorption of micro-nano calcium carbonate when used in cooperation with calcium carbonate.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] 1. The growth protection agent is safe and non-toxic, can be used for bag-free fruit planting instead of bagging, is directly sprayed on the surface of fruit crops during use, has good physical insect prevention effect, can replace bagging, significantly improves the disease resistance and insect prevention ability of fruit trees, and reduces diseased fruits and insect-damaged fruits;

[0038] 2. The growth protection agent is sprayed on the surface of fruits, meets the demand for calcium during the growth of fruit crops, effectively inhibits fruit cracking and fruit drop, increases fruit fullness, improves the calcium content of fruits, and can improve the yield, taste and quality of bagged fruits;

[0039] 3. The growth protection agent can effectively absorb ultraviolet rays and infrared rays, reduce the temperature of the fruit surface, does not affect the transmission of visible light, does not interfere with the normal photosynthesis of fruit crops, is used for bag-free fruit planting, and can significantly improve the taste and quality of bagged fruits. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The scanning electron microscope photograph of calcium carbonate particles in the calcium carbonate slurry prepared in Example 1 is shown in the figure;

[0041] Figure 2 The scanning electron microscope photograph of micro-nano calcium carbonate prepared in Example 1 is shown in the figure;

[0042] Figure 3 The use effect diagram of the growth protection agent prepared in Example 1 on apples is shown in the figure;

[0043] Figure 4 The scanning electron microscope photograph of calcium carbonate particles in the calcium carbonate slurry prepared in Example 2 is shown in the figure;

[0044] Figure 5 The scanning electron microscope photograph of micro-nano calcium carbonate prepared in Example 2 is shown in the figure;

[0045] Figure 6 The use effect diagram of the growth protection agent prepared in Example 2 on pears is shown in the figure;

[0046] Figure 7 The scanning electron microscope photograph of calcium carbonate particles in the calcium carbonate slurry prepared in Example 3 is shown in the figure;

[0047] Figure 8 The scanning electron microscope photograph of micro-nano calcium carbonate prepared in Example 3 is shown in the figure;

[0048] Figure 9 Effect diagram of the use of the growth protection agent prepared using Example 3 on Prunus salicina;

[0049] Figure 10 Effect diagram of the use of the growth protection agent prepared using Example 3 on Prunus salicina;

[0050] Figure 11 Fruit fly damage and rotten fruit of Prunus salicina fruit when the fruit is mature without spraying;

[0051] Figure 12 Scanning electron microscope photograph of calcium carbonate particles in the calcium carbonate mature slurry prepared in Example 4;

[0052] Figure 13 Scanning electron microscope photograph of micro-nano calcium carbonate prepared in Example 4;

[0053] Figure 14 Scanning electron microscope photograph of calcium carbonate particles in the calcium carbonate mature slurry prepared in Example 5;

[0054] Figure 15 Scanning electron microscope photograph of micro-nano calcium carbonate prepared in Example 5;

[0055] Figure 16 Scanning electron microscope photograph of calcium carbonate prepared in Comparative Example 1;

[0056] Figure 17 Effect diagram of the comparison of the dispersion of calcium carbonate prepared in the Examples and the Comparative Example in water;

[0057] Figure 18 Effect diagram of the use of the growth protection agent prepared using calcium carbonate of Comparative Example 1 on apples and comparison diagram of the coloring of the fruit after maturation with Example 1;

[0058] Figure 19 Scanning electron microscope photograph of calcium carbonate prepared in Comparative Example 2;

[0059] Figure 20 Effect diagram of the use of the growth protection agent prepared using calcium carbonate of Comparative Example 2 on pears;

[0060] Figure 21 Effect diagram of the use of the growth protection agent prepared using calcium carbonate of Comparative Example 3 on Prunus salicina;

[0061] Figure 22 Effect diagram of the use of the growth protection agent prepared using calcium carbonate of Comparative Example 4 on apples;

[0062] Figure 23 Effect diagram of the use of the growth protection agent prepared using calcium carbonate of Comparative Example 5 on pears. Specific implementation method

[0063] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0064] In the following examples, the ethoxy-modified polysiloxane is a commercially available product, which is purchased from GE Silicone USA Company, and the model number is Silwet, and the effective ingredient is greater than 98%.

[0065] In the following examples, the polyvinyl acetate emulsion is a commercially available reagent, which is also known as polyvinyl acetate, and the CAS number is 9003-20-7.

[0066] In the following examples, the glycerol is a commercially available reagent, and the CAS number is 56-81-5.

[0067] In the following examples, the modified casein is a commercially available product, which is in the form of a milky white viscous liquid, and the solid content is 20.0±2.0%, the viscosity (20℃) is greater than 100 mPa·s, and the pH value (10% aqueous solution) is 7-8.

[0068] In the following examples, the enzyme is a commercially available agricultural enzyme, which mainly contains agricultural biological agents, and also contains polysaccharides, amino acids and other components, and is purchased from Jining Alida Biological Engineering Co., Ltd., and the model number is MLQ-plant enzyme.

[0069] In the following examples, one or more of xylitol, ribitol, mannitol, sorbitol, maltitol, erythritol and lactitol are used; all the sugar alcohols are commercially available products, and the effective ingredient is greater than 70%.

[0070] Example 1

[0071] The present embodiment provides a calcium-containing growth protective agent for bag-free fruits, which is prepared from the following raw materials in mass parts: monodisperse micro-nano calcium carbonate filter cake 1 part, ethoxy-modified polysiloxane 0.05 part, polyvinyl acetate emulsion 0.02 part, glycerol 0.01 part, modified casein 0.01 part, enzyme 0.01 part, maltitol 0.01 part, and water 5 parts.

[0072] The preparation method of the calcium-containing growth protection agent for bag-free fruits is as follows: according to the above raw materials and mass fractions, 1 part of the monodisperse micro-nano calcium carbonate filter cake is placed in 2 parts of water, and a high-speed dispersion machine is used to stir at a stirring speed of 80 m / min for 40 min. Then, 0.05 parts of ethoxylated polytrisiloxane, 0.02 parts of polyvinyl acetate emulsion, 0.01 parts of glycerol, 0.01 parts of modified casein, 0.01 parts of ferment, 0.01 parts of maltitol, and the remaining 3 parts of water are added according to the above formula, and the stirring is continued at a stirring speed of 80 m / min for 20 min, to obtain the growth protection agent of the present embodiment, and the solid content of calcium carbonate is about 10%.

[0073] In the present embodiment, the monodisperse micro-nano calcium carbonate filter cake used is prepared by the following steps:

[0074] S1. A calcium carbonate slurry is prepared by calcination, digestion, and carbonization processes. In the calcination process, limestone with a grain size of 0.2-0.5 mm and a content of harmful heavy metals such as cadmium, lead, and chromium less than 400 ppm is selected as the raw material, and the raw material is calcined at a temperature of 900°C for 2 h to obtain active quicklime. In the digestion process, the quicklime obtained by calcination is digested with water at 90°C to obtain lime milk, and the refined slurry is obtained by removing impurities after 24 h of storage. In the carbonization process, the refined slurry obtained by digestion is adjusted to a solid content of 6% by adding water, and then carbonized. The initial carbonization temperature is 10°C, the CO2 content is 40%, and the carbonization is stopped when the slurry pH reaches 8.5-9.0, to obtain the calcium carbonate slurry.

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

[0076] S2. The calcium carbonate slurry obtained in S1 is added with 0.5% aluminum chloride, 0.5% polyvinylpyrrolidone, 2.5% sodium dodecyl sulfate, and 2.0% polyvinyl alcohol based on the mass of calcium carbonate, and is kept at 140°C for 2.0 h to obtain a calcium carbonate suspension.

[0077] S3. The calcium carbonate suspension obtained in S2 is filtered and dewatered to obtain a calcium carbonate filter cake, and the moisture content of the filter cake is controlled to be between 35% and 40%, that is, a monodisperse micro-nano calcium carbonate, at this time, a proper amount of the filter cake is dried at 105°C, and then the composition, specific surface area, microscopic morphology and particle size of the dried filter cake are tested and analyzed, the composition and specific surface area are tested according to the standard of "Calcium Carbonate Analysis Method" (GB / T 19281-2014), and the microscopic morphology and particle size are tested according to the standard of "Nano Calcium Carbonate" (GB / T 19590-2023). The harmful impurities such as cadmium, lead, barium, mercury and arsenic in the obtained monodisperse micro-nano calcium carbonate are less than 0.0002%, and the total content of harmful impurities is less than 200 ppm; the specific surface area is about 19.89 m 2 / g; it can be clearly seen from the scanning electron microscope photos (see Figure 2 ) that the average particle size of the obtained monodisperse micro-nano calcium carbonate is about 65 nm, and the particles are cubic with smooth and clean surfaces. The monodisperse micro-nano calcium carbonate filter cake is dispersed in clean water to obtain a suspension with a solid content of 2%, and then the suspension effect is observed after standing for 2 h (see Figure 17 ).

[0078] When used for spraying apples: before the fruit expansion period of apples, the growth protection agent prepared in this example is diluted 10 times (the solid content of calcium carbonate is about 1%) and sprayed on the surface of apple fruits, and the spraying process does not need to specially avoid the leaves and branches of the apple trees. After spraying, the growth status of the whole apple tree is recorded by taking photos, and then the apples are observed regularly every week, and the apples need to be sprayed 2-3 times during the ripening process. If it rains for more than 5 days continuously, and the total rainfall reaches 250 mm or more, it needs to be sprayed once after the rain. The sprayed orchards are Jin'yan Orchard, Huai Bai Base Orchard and Nanhe Su Orchard.

[0079] The use effect of the growth protection agent of this example on apples is shown in Figure 3 .

[0080] After the apples are sprayed with the growth protection agent of this example (set), the influence on the tree vigor index is compared with that of the control (ck), and the results are shown in Table 1. As can be seen from the table, spraying the growth protection agent of this example can improve the growth vigor of the tree. In the test, the fresh weight of the leaves of Jin'yan Orchard increased by 2.24%, the dry weight of the leaves decreased by 1.46%, and the thickness of the leaves increased by 1.17%; the fresh weight of the leaves of Huai Bai Base Orchard increased by 5.22%, the dry weight of the leaves increased by 3.54%, and the thickness of the leaves increased by 3.95%; the fresh weight of the leaves of Nanhe Su Orchard increased by 6.17%, the dry weight of the leaves increased by 3.04%, and the thickness of the leaves increased by 8.637%.

[0081] Table 1 Comparison of tree vigor index

[0082]

[0083] The influence of the growth protection agent of the present embodiment on the appearance indexes of the fruits is shown in Table 2. As shown in the table, the growth protection agent of the present embodiment has little influence on the fruit shape index, but can improve the brightness and color of the fruits. The brightness of the fruits of Jinyuan Garden is improved by 9.9%, the redness is improved by 19.8%, and the yellowness is reduced by 31.8%; the brightness of the fruits of Huobai Base Garden is improved by 5.5%, the redness is improved by 18.7%, and the yellowness is reduced by 28.6%; the brightness of the fruits of Nanhelu Garden is improved by 19.6%, the redness is improved by 43.5%, and the yellowness is reduced by 10.8%.

[0084] Table 2 Comparison of fruit appearance indexes

[0085]

[0086] (Note: 0.6 < fruit shape index < 0.8 represents that the fruit is flat and round, 0.8 < fruit shape index < 0.9 represents that the fruit is round or nearly round; L represents the brightness value.)

[0087] The influence of the growth protection agent of the present embodiment on the internal quality of the fruits is shown in Table 3. As shown in the table, the growth protection agent of the present embodiment can improve the internal quality of the fruits. In the test, the weight of the single fruit of Jinyuan Garden is increased by 1.68%, the hardness is improved by 2.3%, the soluble solids are improved by 2.2%, the titratable acid is improved by 23.9%, and the ratio of the solid to the acid is reduced by 17.5%; the weight of the single fruit of Huobai Base Garden is increased by 6.1%, the hardness is improved by 0.6%, the soluble solids are improved by 3.2%, the titratable acid is improved by 2.2%, and the ratio of the solid to the acid is reduced by 1.0%; the weight of the single fruit of Nanhelu Garden is increased by 9.5%, the hardness is improved by 0.2%, the soluble solids are improved by 4.0%, the titratable acid is improved by 14.3%, and the ratio of the solid to the acid is reduced by 9.0%. The bagging of the apples influences the internal quality of the fruits, and makes the weight, hardness, sugar, acid, and VC content of the fruits reduced, and the flavor of the fruits changed. The growth protection agent of the present embodiment can improve the calcium content in the fruits. The calcium content in the peel of Jinyuan Garden is increased by 12.4%, and the calcium content in the pulp is increased by 49.8%; the calcium content in the peel of Huobai Base Garden is increased by 16.4%, and the calcium content in the pulp is increased by 16.1%; the calcium content in the peel of Nanhelu Garden is increased by 14.0%, and the calcium content in the pulp is increased by 5.7%.

[0088] Table 3 Comparison of internal quality of fruits

[0089]

[0090] The cost of the growth protection agent of the present embodiment is calculated in detail, and the cost per mu per year is only about 330 yuan. The specific calculation of the cost is as follows: about 100 fruit trees per mu, annual fruit yield of about 2500 kg, growth protection agent dosage of 25 kg / mu, and the unit price of the growth protection agent is about 5 yuan / kg. The machine rental fee (including labor cost) is about 40 yuan / mu·time. The cost of spraying twice a year per mu is 330 yuan (2*25*5+2*40). The bagging cost is calculated as follows: about 10000 bags per mu, and the labor cost of bagging is about 0.24 yuan / bag. The labor cost of bagging is 2400 yuan / mu (10000*0.24). Compared with manual bagging, spraying the growth protection agent of the present embodiment can save 2070 yuan per mu, greatly improving the economic benefit and having a broad market prospect.

[0091] Embodiment 2

[0092] The present embodiment provides a calcium-containing growth protection agent for bag-free fruits, which is prepared by using the following mass ratio: 10 parts of monodisperse micro-nano calcium carbonate filter cake, 0.4 parts of ethoxylated 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 115 parts of water.

[0093] The preparation method of the calcium-containing growth protection agent for bag-free fruits of the present embodiment is as follows: 10 parts of monodisperse micro-nano calcium carbonate filter cake is placed in 15 parts of water, and stirred at a stirring speed of 120 m / min for 15 min using a high-speed dispersing machine. Then, 0.4 parts of ethoxylated 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, and stirring is continued at a stirring speed of 90 m / min for 30 min. Thus, the growth protection agent of the present embodiment is obtained, and the solid content of calcium carbonate is about 5%. The preparation steps of the monodisperse micro-nano calcium carbonate filter cake are different from those of embodiment 1 in that the digestion temperature of step S1 is 70℃, the aging time is 35h, the refined slurry solid content during carbonization is 8%, the carbonization starting temperature is 22℃, the CO2 content is 30%, the carbonization is stopped when the pH reaches 8.0-8.5, and the calcium carbonate particles in the obtained mature slurry are characterized by microscopic morphology. It can be observed that the calcium carbonate particles are nearly spherical with an average particle size of about 70 nm (see Figure 4 ); 0.5% sodium silicate, 1.5% aluminum chloride and 2% polyethylene glycol based on the mass of calcium carbonate are added during the crystal grain surface reconstruction process, and the temperature is kept at 140℃ for 4h.

[0094] The monodisperse micro-nano calcium carbonate filter cake obtained in the example was tested for composition, specific surface area, micro-morphology and particle size using the same test method as in Example 1. The harmful impurities such as cadmium, lead, barium, mercury and arsenic in the obtained monodisperse micro-nano calcium carbonate were less than 0.0002%, and the total content of harmful impurities was less than 200 ppm; the specific surface area was about 18.53 m 2 / g; from the SEM photos (see Figure 5 ), it can be clearly seen that the average particle size of the obtained monodisperse micro-nano calcium carbonate particles was about 110 nm, and the particles were cubic with smooth and clean surfaces. The monodisperse micro-nano calcium carbonate filter cake was dispersed in clean water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 h (see Figure 17 ).

[0095] For spraying on pears: before the fruit expansion stage of pears, dilute the calcium-containing growth protectant for bag-free fruits 2 times (the solid content of calcium carbonate is about 2.5%) and spray it on the surface of the pear fruits. After spraying, record the growth status of the whole pear tree by taking pictures, and then observe regularly every week. During the ripening process of pears, 1-2 times of spraying are needed. If there is continuous rainfall for more than 5 days, and the total rainfall reaches 250 mm or more, one time of supplementary spraying is needed after the rain, and make sure that there is no rain for 24 hours before supplementary spraying.

[0096] The use effect of the growth protectant prepared in the example on pears is shown in Figure 6 , and the protectant can quickly spread on the surface of the fruits and adhere uniformly.

[0097] Spraying the growth protectant prepared in the example can well protect pears and greatly reduce the fruit drop rate. The specific data is shown in Table 4.

[0098] Table 4 Comparison of pear fruit drop and insect fruit effect

[0099]

[0100] Note: 20 pear trees in the same orchard area were randomly selected for comparison.

[0101] The cost of the product of the embodiment is calculated in detail, and the cost of each mu of land per year is only about 700 yuan. The specific calculation of the cost is as follows: about 100 trees per mu of land, annual fruit yield is about 3000 kg, growth agent dosage is 100 kg / mu, the unit price of growth protection agent is about 2.5 yuan / kg, manual spraying operation is adopted, and the labor cost is about 100 yuan / mu·time. The cost of spraying twice a year per mu of land is 700 yuan (2*100*2.5+2*100); the bagging cost is calculated as follows: about 10000 bags per mu of land are needed, and the manual bagging cost is about 0.13 yuan / bag, so the manual bagging cost is 1300 yuan / mu (10000*0.13). Spraying the growth protection agent of the embodiment can save 600 yuan per mu compared with manual bagging, improve economic benefits, and has broad market prospects.

[0102] Embodiment 3

[0103] The calcium-containing growth protection agent for bag-free fruits of the embodiment is prepared from the following raw materials in parts by mass: monodisperse micro-nano calcium carbonate filter cake 15 parts, ethoxylated polytrisiloxane 0.2 parts, polyvinyl acetate emulsion 0.8 parts, modified casein 0.2 parts, enzyme 0.5 parts, ribitol 0.9 parts, and water 45 parts.

[0104] The preparation method of the calcium-containing growth protection agent for bag-free fruits of the embodiment is as follows: 15 parts of monodisperse micro-nano calcium carbonate filter cake is placed in 20 parts of water, and stirred at a stirring speed of 90 m / min for 30 min using a high-speed dispersing machine. Then, 0.2 parts of ethoxylated 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, and stirring is continued at a stirring speed of 110 m / min for 25 min. Thus, the growth protection agent of the embodiment is obtained, and the solid content of calcium carbonate is about 15%. In the preparation steps of the monodisperse micro-nano calcium carbonate filter cake, the difference from embodiment 1 is that the digestion temperature of step S1 is 80°C, the aging time is 30 h, the refined slurry solid content during carbonization is 5%, the carbonization starting temperature is 30°C, the CO2 content is 20%, the carbonization is stopped when the pH reaches 8.0-9.0, and the calcium carbonate particles in the obtained mature slurry are characterized by microscopic morphology. It can be observed that the calcium carbonate particles are in short chain form, and the average width is about 61 nm (see Figure 7 ); 0.2% zinc sulfate, 0.5% sodium silicate, 1.4% polyethylene glycol, and 0.6% cetyltrimethylammonium bromide are added to the calcium carbonate dry base during the crystal grain surface reconstruction process, and the temperature is kept at 180°C for 2.5 h.

[0105] The monodisperse micro-nano calcium carbonate filter cake obtained in the example was tested for composition, specific surface area, micro-morphology and particle size using the same test method as in Example 1. The harmful impurities of 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 about 17.26 m2 / g; and the average particle size of the obtained monodisperse micro-nano calcium carbonate was about 150 nm, as shown in the SEM photos (see 2 ).The obtained monodisperse micro-nano calcium carbonate filter cake was dispersed in clean water to obtain a suspension with a solid content of 2%, and the suspension effect was observed after standing for 2 h. The suspension was still stable (see Figure 8 ). Figure 17

[0106] For planting plum: during the fruit swelling period of plum, on sunny days, the growth protection agent was diluted 5 times using a conventional sprayer (the solid content of calcium carbonate was about 3%) and sprayed on the surface of plum fruits. There was no need to specially avoid the leaves and branches of the plum trees. After spraying, the growth status of the plum trees was recorded by taking photos, and the plum trees were observed regularly every week thereafter. If it rained for more than 5 days, and the total rainfall reached 250 mm or more, the plum trees needed to be sprayed again after the rain. If there was no rain before harvesting, there was no need to spray again.

[0107] The use effect of the growth protection agent prepared in the example on plum is shown in Figure 9 . The growth protection agent was evenly attached to the surface of the plum fruits and leaves, forming a thin and uniform protective film.

[0108] The mature plum fruits and the bagged mature plums after spraying the growth protection agent prepared in the example on the surface of the plum are shown in Figure 10 . The bagging isolated the sunlight, and the chlorophyll on the fruit skin was less, so that the mature plum was light yellow. At the same time, due to weak photosynthesis, the sugar content, vitamins, proteins and other substances in the fruit were correspondingly reduced, so that the sweetness was not good and the fruit aroma was lacking. The plum sprayed with the growth protection agent prepared in the example was light yellow-green after maturation, and had a crisp and sweet taste and a rich fruit aroma.

[0109] The plum sprayed with the growth protection agent prepared in the example had no fruit fly pests, while the natural fruits without treatment had many fruit fly eggs and bad hearts (see Figure 11 ). The comparison of the fruit fly pest prevention effect of the growth protection agent prepared in the example with bagging and no treatment is shown in Table 5. The fruit fly prevention effect of the plum sprayed with the growth protection agent prepared in the example was much higher than that of no treatment, and was the same as that of bagging.

[0110] Table 5 Comparison of fruit fly pest prevention effect

[0111] Protection method No treatment Bagging Spraying the growth protectant of the present embodiment Number of guavas in which fruit fly eggs appeared 32 0 0

[0112] Note: Randomly selected 100 fruits from 10 trees in the same orchard for comparison.

[0113] The price of the product of the present embodiment is calculated in detail, and the cost per mu per year is only about 950 yuan. The specific cost calculation is as follows: about 100 trees per mu, annual fruit yield about 3000 jin, growth agent dosage 50 kg / mu, growth protection agent unit price about 7.5 yuan / kg, manual spraying operation, labor cost about 100 yuan / mu·time, two times of spraying per year, the cost of one mu is 950 yuan (2*50*7.5+2*100); the cost of bagging is calculated as follows: about 20,000 bags per mu, the cost of manual bagging is about 0.1 yuan per bag, so the cost of manual bagging is 2000 yuan per mu (20000*0.1). Spraying the growth protection agent of the present embodiment can save 1050 yuan per mu compared with manual bagging, improve economic benefits, and has broad market prospects.

[0114] Embodiment 4

[0115] The present embodiment provides a calcium-containing growth protection agent for bag-free fruits, which is prepared from the following raw materials in parts by mass: monodisperse micro-nano calcium carbonate filter cake 5 parts, ethoxylated polytrisiloxane 0.3 parts, polyvinyl acetate emulsion 0.2 parts, modified casein 0.1 parts, enzyme 0.2 parts, lactitol 0.1 parts, and water 25 parts.

[0116] The preparation method of the calcium-containing growth protection agent for bag-free fruits of the present embodiment is as follows: according to the above raw materials and mass parts, 8 parts of monodisperse micro-nano calcium carbonate filter cake is placed in 8 parts of water, and stirred with a high-speed disperser at a stirring line speed of 110 m / min for 20 min, then 0.3 parts of ethoxylated 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, and continue to stir at a stirring line speed of 80 m / min for 30 min, to obtain the growth protection agent of the present embodiment. The solid content of calcium carbonate is about 10%. In the preparation steps of monodisperse micro-nano calcium carbonate filter cake, the difference from embodiment 1 is that the digestion temperature of step S1 is 60℃, the aging time is 40h, the refined slurry solid content during carbonization is 12%, the carbonization starting temperature is 10℃, the CO2 content is 35%, the carbonization is ended when the pH reaches 8.0-8.5, and the calcium carbonate particles in the obtained mature slurry are characterized by microscopic morphology after carbonization is completed. It can be observed that the calcium carbonate particles are nearly spherical with an average particle size of about 53 nm (see Figure 12 ); 1% sodium silicate, 1.5% polyvinyl alcohol and 1.5% sodium dodecylbenzenesulfonate of the mass of calcium carbonate dry base are added during the crystal grain surface reconstruction process, and the temperature is kept at 200℃ for 1h.

[0117] The monodisperse micro-nano calcium carbonate filter cake obtained in this example was tested for composition, specific surface area, microscopic morphology and particle size using the same test methods as in Example 1. The harmful impurities of 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 about 18.24 m 2 / g; from the SEM photos (see Figure 13 ), it can be clearly seen that the average particle size of the obtained monodisperse micro-nano calcium carbonate particles was about 120 nm, and the particles were cubic with smooth and clean surfaces. The monodisperse micro-nano calcium carbonate filter cake was dispersed in clean water to obtain a suspension with a solid content of 2%, and then the suspension effect was observed after standing for 2 h (see Figure 17 ).

[0118] For guava planting: one month after fruit setting, when the young fruit longitudinal diameter reaches 3-4 cm and the fruit starts to droop, choose sunny days, dilute the growth protection agent 10 times (the solid content of calcium carbonate is about 1%) with a conventional sprayer and spray it on the surface of guava fruit. There is no need to specially avoid the leaves and branches of the fruit trees. After spraying, take photos to record the growth status of the whole guava tree, and then observe it regularly every week. If it rains for more than 5 days, and the total rainfall reaches 250 mm or more, it needs to be sprayed again after the rain. Before the fruit matures, generally in mid-August of each year, it needs to be sprayed again.

[0119] The guavas sprayed with the growth protection agent prepared in this example have no fruit fly pests, and the natural fruits without treatment have more fruit fly eggs and bad hearts. The comparison of the effects of preventing fruit fly pests between spraying the growth protection agent prepared in this example, bagging and no treatment is shown in Table 6. The effect of preventing fruit fly pests of guavas sprayed with the growth protection agent prepared in this example is much higher than that of no treatment, and is basically the same as that of bagging.

[0120] Table 6 Comparison of effects of preventing fruit fly pests

[0121] Protection method No treatment Bagging Spraying the growth protectant of the present embodiment Number of guavas in which fruit fly eggs appeared 186 0 2

[0122] Note: 400 guavas on 20 guava trees in the same orchard were randomly selected for comparison (20 guavas were taken from each tree).

[0123] The cost of the product of the embodiment is calculated in detail, and the cost of each mu of land per year is only about 700 yuan. The specific calculation of the cost is as follows: the annual fruit yield of one mu of land is about 3000 kg, the growth agent dosage is 50 kg / mu once, the unit price of the growth protection agent is about 5 yuan / kg, the artificial spraying operation is adopted, and the labor cost is about 100 yuan / mu·time. The cost of spraying twice a year in one mu of land is 700 yuan (2*50*5+2*100); the cost of bagging is calculated as follows: one mu of land needs to be bagged about 8000 bags / mu, and the artificial bagging cost is about 0.16 yuan / bag, so the artificial bagging cost is 1280 yuan / mu (8000*0.16). Spraying the growth protection agent of the embodiment can save 580 yuan per mu compared with artificial bagging, improve the economic benefit, and has a broad market prospect.

[0124] Embodiment 5

[0125] The embodiment provides a calcium-containing growth protection agent for bag-free fruits, which is prepared from raw materials in the following mass fractions: monodisperse micro-nano calcium carbonate filter cake 20 parts, ethoxy-modified polytrisiloxane 0.5 part, polyvinyl acetate emulsion 0.9 part, glycerol 0.2 part, modified casein 0.8 part, enzyme 0.2 part, sorbitol 0.1 part, and water 180 parts.

[0126] The preparation method of the calcium-containing growth protection agent for bag-free fruits is as follows: 3 parts of monodisperse micro-nano calcium carbonate filter cake are placed in 30 parts of water, and stirred at a stirring speed of 80 m / min for 40 min by using a high-speed dispersion machine. Then, 0.5 part of ethoxy-modified polytrisiloxane, 0.9 part of polyvinyl acetate emulsion, 0.2 part of glycerol, 0.8 part of modified casein, 0.2 part of enzyme, 0.1 part of sorbitol, and the remaining 150 parts of water are added according to the above formula, and stirring is continued at a stirring speed of 80 m / min for 30 min, to obtain the growth protection agent of the embodiment. The solid content of calcium carbonate is about 6%.

[0127] The preparation steps of the monodisperse micro-nano calcium carbonate filter cake are different from those of Embodiment 1 in that the digestion temperature of step S1 is 50°C, the aging time is 48 h, the refined slurry solid content during carbonization is 10%, the carbonization starting temperature is 25°C, the CO2 content is 33%, the carbonization is ended when the pH reaches 7.5-8.5, and the calcium carbonate particles in the obtained mature slurry are characterized by microscopic morphology after the carbonization is ended. It can be observed that the calcium carbonate particles are chain-shaped, and the average width is about 68 nm (see Figure 14 ); 1.5% of sodium chloride, 0.5% of sodium silicate, 1% of zinc sulfate, 0.5% of ethanol, and 0.5% of disodium ethylenediaminetetraacetate are added during the crystal grain surface reconstruction process, and the temperature is kept at 190°C for 3 h.

[0128] The monodisperse micro-nano calcium carbonate filter cake obtained in the example was tested for composition, specific surface area, microscopic morphology and particle size using the same test method as in Example 1. The harmful impurities of 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 about 16.92 m2 / g; and the average particle size of the obtained monodisperse micro-nano calcium carbonate particles was about 195 nm, as shown in the SEM photos (see 2 ).The monodisperse micro-nano calcium carbonate particles were cubic in shape and had smooth and clean surfaces. The monodisperse micro-nano calcium carbonate filter cake was dispersed in clean water to obtain a suspension with a solid content of 2%, and the suspension was then observed for suspension effect after standing for 2 h (see Figure 15 ). Figure 17

[0129] For honey pomelo planting: when the fruit diameter reaches 3-5 cm, choose sunny days, dilute the growth protection agent 3 times (the solid content of calcium carbonate is about 2%) with a conventional sprayer, and directly spray it on the surface of the honey pomelo fruit. There is no need to specially avoid the leaves and branches of the fruit tree. After spraying, take photos to record the growth status of the whole pomelo tree, and then observe it regularly every week. If it rains for more than 5 days, and the total rainfall reaches 250 mm or more, it needs to be sprayed again after the rain. If there is no rain before picking, there is no need to spray again.

[0130] The honey pomelo sprayed with the growth protection agent prepared in the example has basically no fruit borer and fruit moth pests, and the natural fruits without treatment have more pest fruits and cracked fruits, and there are more dry and water fruits near the fruit stem. The comparison of the growth protection agent prepared in the example with bagging and no treatment for pest control and crack fruit prevention is shown in Table 7. The effect of pest control and crack fruit prevention of the honey pomelo sprayed with the growth protection agent prepared in the example is much higher than that of no treatment, and is basically the same as that of bagging.

[0131] Table 7 Comparison of pest control and crack fruit prevention effects

[0132] Protection method No treatment Bagging Spraying the growth protectant of the present embodiment Number of pomelos in which fruit fly eggs appeared 52 0 1 Number of pomelos in which fruit fly eggs appeared 21 0 1

[0133] Note: 200 honey pomelo fruits in the same orchard area were randomly selected for comparison.

[0134] The price of the product of the present embodiment is calculated in detail, and the cost per mu per year is only about 600 yuan. The specific calculation of the cost is as follows: the annual fruit yield of one mu is about 5000 kg, the growth agent dosage is 100 kg / mu once, the unit price of the growth protection agent is about 2 yuan / kg, the labor cost is about 100 yuan / mu·time, and the cost of spraying twice a year in one mu is 700 yuan (2*100*2+2*100); the bagging cost is calculated as follows: one mu needs to be bagged about 5000 bags / mu, and the labor cost of bagging is about 0.3 yuan / bag, so the labor cost of bagging is 1500 yuan / mu (5000*0.3). Spraying the growth protection agent of the present embodiment can save 900 yuan per mu compared with manual bagging, improve economic benefits, and has broad market prospects.

[0135] Comparative Example 1

[0136] Comparative Example 1 has the same formula as Example 1, except that no inorganic crystal grain surface modifier is added in the preparation method of calcium carbonate. The microscopic morphology of the obtained product is shown in Figure 16 .

[0137] Because no inorganic crystal grain surface modifier is added in Comparative Example 1, the surface of calcium carbonate crystal grains is rough, and the dispersibility between particles is relatively poor. Particles are connected to each other, resulting in a decrease in dispersion stability in water, as shown in Figure 17 . And because of hard agglomeration of particles, the film formed on the surface of apple after spraying is uneven (see Figure 18 left), and better protection cannot be achieved. The coloring of the surface of the apple after ripening is uneven (see Figure 18 right).

[0138] Comparative Example 2

[0139] Comparative Example 2 has the same formula as Example 2, except that no organic crystal grain surface modifier is added in the preparation method of calcium carbonate. The microscopic morphology of the obtained product is shown in Figure 19 .

[0140] Because no organic crystal grain surface modifier is added in Comparative Example 2, the surface of calcium carbonate crystal grains is clean, but the dispersibility between particles is still relatively poor. Particles are connected to each other, resulting in a decrease in dispersion stability in water, as shown in Figure 17 . And because of hard agglomeration of particles, the film formed on the surface of pear after spraying is uneven (see Figure 20 ), and better protection cannot be achieved. There are many spots on the surface of the fruit.

[0141] Comparative Example 3

[0142] Comparative Example 3 has the same preparation method of calcium carbonate as Example 3, except that no ethoxylated modified polysiloxane, polyvinyl acetate emulsion modified casein, and other auxiliary materials are added in the formula.

[0143] Comparative Example 3 Figure 21

[0144] Comparative Example 4

[0145] Comparative Example 4 has the same formula as Example 1, except that the preparation method of calcium carbonate does not perform filter pressing to obtain a special morphology of monodisperse calcium carbonate filter cake, but directly obtains the slurry after the surface reconstruction of the crystal grains, and then the slurry is prepared according to the formula of Example 1.

[0146] Comparative Example 4 does not perform filter pressing to remove soluble ions in the slurry, and is sprayed on the apple fruit surface. Harmful ions have an impact on the fruit surface, and there are many spots on the fruit surface after maturation, as shown in Figure 22

[0147] Comparative Example 5

[0148] Comparative Example 5 has the same formula as Example 2, except that the preparation method of the growth protection agent does not follow the two-step dispersion procedure, but 10 parts of monodisperse micro-nano calcium carbonate filter cake is directly added to 115 parts of water, and a high-speed dispersing machine is used to stir at a stirring line speed of 120 m / min for 15 min. After uniform stirring, ethoxylated modified polysiloxane, polyvinyl acetate emulsion, glycerol, modified casein, enzyme, and mannitol are added according to the formula, and the stirring is continued at a stirring line speed of 100 m / min for 15 min.

[0149] Comparative Example 5 does not have a high concentration stirring step, resulting in poor dispersion of calcium carbonate. When sprayed on the pear fruit surface, the slurry cannot form a good film on the fruit surface, there are local differences in concentration, and more accumulation in the fruit peduncle part, resulting in more spots on the fruit surface after maturation, and a high fruit drop rate, as shown in Figure 23

[0150] Comparative Example 6

[0151] Comparative Example 6 has the same preparation method of calcium carbonate as Example 1, except that the formula does not add modified casein, enzyme, and maltitol.

[0152] Comparative Example 6 does not add auxiliary materials, and when used for apple bagless planting, the calcium supplement and insect prevention effect is poor. Compared with the spraying of Example 1, the calcium content of Jinyuan Orchard fruit meat decreases by 19.5%, the calcium content of Huobai Base Orchard fruit meat decreases by 6.7%, and the calcium content of Nanheshu Orchard fruit meat decreases by 4.5%.

[0153] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the inventive concept, several improvements and changes can be made, which are within the scope of protection of the present application.​​​

Claims

1. A calcium-containing growth protectant for fruit that does not require bagging, characterized in that, The raw material composition, by mass parts, 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%, and the calcium carbonate particles are cubic or nearly spherical in shape, with an average particle size between 50 and 200 nm. Particles larger than 200 nm account for less than 5%, and the specific surface area is less than 20 m². 2 / g; and the monodisperse micro-nano calcium carbonate filter cake remains stable in suspension when stirred and dispersed in aqueous solution without the addition of any chemical dispersant; The preparation method of the calcium-containing growth protectant for bagless fruits is as follows: a monodisperse micro-nano calcium carbonate filter cake is placed in a portion of water at a temperature of 5-30℃ and dispersed in a high-speed disperser at a linear velocity of 80-120 m / min for 15-40 min. Then, other raw materials and the remaining water are added, and the mixture is dispersed in a high-speed disperser at a linear velocity of 80-120 m / min for 15-30 min to obtain the calcium-containing growth protectant for bagless fruits.

2. The calcium-containing growth protectant for bagged-free fruits according to claim 1, characterized in that, The raw materials, calculated by weight proportions, include: 1-20 parts of monodisperse micro / nano calcium carbonate filter cake, 0.05-0.5 parts of ethoxylated modified polytrisiloxane, 0.02-0.8 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, and when the solid content of the suspension is 5%-30%, it is stably suspended for more than 14 hours.

3. The calcium-containing growth protectant for bagged-free fruits according to claim 1, characterized in that, 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.

4. The calcium-containing growth protectant for bagged-free fruits according to claim 3, characterized in that, 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.

5. A calcium-containing growth protectant for bagged-free fruits according to claim 3, characterized in that, The inorganic salt grain surface reconstructing 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; the organic grain surface reconstructing 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.

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

7. A method for preparing the calcium-containing growth protectant for bagged fruit according to any one of claims 1 or 3 to 6, characterized in that, Includes 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.

8. The method for preparing the calcium-containing growth protectant for bagged fruit according to claim 7, characterized in that, 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.

9. The method of applying the calcium-containing growth protectant for bagged fruits according to any one of claims 1 to 6, characterized in that: When used to prevent fruit cracking and improve coloring, the calcium-containing growth protectant for bagged 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 bagged fruits is diluted with water to a calcium carbonate solid content of 1% to 3% before spraying.

10. The method for applying the calcium-containing growth protectant for bagged fruits according to claim 9, characterized in that, In dry, rainless weather, dilute the calcium-containing growth protectant and spray it onto the fruit surface. There is no need to avoid branches and leaves. Spray 2-4 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 250mm or more, it is necessary to spray again after the rain.

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