Preparation method of seaweed foliar fertilizer for promoting fruit color change

Abstract

The application relates to the technical field of vegetable planting, and particularly discloses a preparation method of seaweed foliar fertilizer for promoting fruit color change. The preparation method comprises the following steps: mixing seaweed enzymolysis liquid, potassium dihydrogen phosphate, amino acid, humic acid, chitosan microcapsule and modified wheat shell, stirring at 60-65 DEG C for 1-2 hours, and standing to obtain seaweed foliar fertilizer. The seaweed foliar fertilizer prepared by the method not only promotes the color change of fruits, but also is environment-friendly, improves soil quality, has smaller environmental burden, and meets the green agricultural standard.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of vegetable planting, and more particularly to a preparation method of seaweed foliar fertilizer for promoting fruit color change. BACKGROUND

[0002] In the process of fruit planting, the color change of fruit during the ripening process is a sign of fruit maturity, mainly involving the dynamic changes of three pigments: chlorophyll, carotenoids and anthocyanins. During the ripening of fruit, chlorophyll gradually degrades, and the content of carotenoids and anthocyanins increases, resulting in the color change of fruit from green to yellow, orange, red or purple. This process is accompanied by cell wall metabolism, accumulation of aromatic compounds, synthesis of antioxidant and polyphenol substances, and changes in hormone content, finally reaching the edible level, and gradually showing the inherent color and aroma of the variety.

[0003] At present, the main color change products on the market mainly use growth regulators, but the use time and dosage of such substances are relatively strict. If not careful, the fruit grains may become soft, dark, easy to fall off, and the storage and transportation resistance of the fruit products may decrease, and even cause leaf fall and tree decline and many other problems. Moreover, excessive growth regulators may be left in the soil, affecting the activity of soil microorganisms, or entering water bodies through water circulation, causing potential threats to the ecological environment.

[0004] Therefore, it is urgent to find a green, safe and effective color change product. SUMMARY

[0005] In order to improve the problem that long-term use of growth regulators pollutes the environment, the application provides a preparation method of seaweed foliar fertilizer for promoting fruit color change.

[0006] In a first aspect, the application provides a preparation method of seaweed foliar fertilizer for promoting fruit color change, which adopts the following technical scheme:

[0007] The preparation method of seaweed foliar fertilizer for promoting fruit color change comprises the following steps: mixing seaweed enzymatic hydrolysate, potassium dihydrogen phosphate, amino acid, humic acid, chitosan microcapsule and modified wheat shell, stirring at 60-65 DEG C for 1-2 h, and standing to obtain seaweed foliar fertilizer.

[0008] By adopting the above technical scheme, the seaweed enzymatic solution is rich in natural growth promoting substances such as plant hormones, minerals and trace elements, which can be quickly absorbed by the leaf surface to provide additional nutrients for crops, promote healthy growth, help the healthy maturation of fruits, and promote fruit color change; amino acids, as the basic component of plant growth, can quickly supplement the nitrogen elements required by plants through foliar absorption, both inorganic nitrogen and organic nitrogen, promoting the healthy growth of plants, promoting the overall health and photosynthesis of plants, and promoting the natural color change of fruits; potassium dihydrogen phosphate contains phosphorus and potassium necessary for plant growth, promotes photosynthesis, enhances plant stress resistance, and as a growth regulator, helps plants respond quickly during the key growth period, such as promoting flower bud differentiation, improving fruit color and maturity.

[0009] Humic acid can improve the availability of soil and leaf surface nutrients, and in combination with amino acids, it can promote plant nutrient absorption, especially trace element absorption, improve nutrient use efficiency, promote root development, speed up plant metabolism, and help improve crop growth speed and health status, promote fruit ripening process, and improve fruit color, taste and nutrient content; chitosan microcapsules can encapsulate active ingredients in foliar fertilizer, control the degradation rate of the capsule, and achieve slow release of nutrients, which can prolong the fertilizer effect, reduce nutrient loss, and improve use efficiency.

[0010] Chitosan itself is a natural biological stimulant that can promote root development, enhance the immune system of plants, and improve resistance to pests and diseases, while promoting the natural growth process of plants. The properties of chitosan help improve the adhesion of foliar fertilizer, reduce rainwater erosion, and possibly promote nutrient penetration into the plant body through its unique molecular structure; modified wheat shell as a carrier for foliar fertilizer improves the uniformity of foliar fertilizer spraying, allowing it to better adhere to the leaf surface, prolonging the contact time of nutrients and improving absorption efficiency; as an organic substance, it can provide organic matter to the soil during natural degradation, indirectly promoting soil microbial activity and improving soil environment.

[0011] The above components work together to enhance nutrient utilization efficiency, achieve nutrient additive effect, promote rapid nutrient replenishment, promote internal metabolic processes in fruits, ensure that necessary nutrients are obtained during fruit ripening, help the synthesis of carotenoids and anthocyanins, promote fruit color change, and the fertilizer is environmentally friendly, improves soil quality, has less environmental burden, and meets the standards of green agriculture.

[0012] Optionally, the seaweed enzymatic solution is 30-40 parts by weight, potassium dihydrogen phosphate is 5-9 parts by weight, amino acid is 20-25 parts by weight, humic acid is 3-6 parts by weight, chitosan microcapsule is 10-15 parts by weight, and modified wheat shell is 5-8 parts by weight.

[0013] By adopting the technical scheme, the use amount of each component is further limited, so that each component has a better effect in the limited use amount range, the natural growth promoting substances such as plant hormones, minerals and trace elements in the seaweed enzymatic hydrolysate help the healthy maturation of fruits, promote the fruit color change, cooperate with potassium dihydrogen phosphate, amino acids and humic acid, help to improve the growth speed and health status of crops, and promote the maturation process of fruits; the chitosan microcapsule realizes slow release of nutrients by controlling the degradation rate of the capsule, which can prolong the fertilizer effect, and the modified wheat shell makes the components better adhere to the leaf surface, prolongs the contact time of nutrients, and improves the absorption efficiency.

[0014] Optionally, the preparation method of the chitosan microcapsule comprises the following steps:

[0015] (1) mixing petroleum ether, modified liquid paraffin and span-80, stirring at a temperature of 70-75℃ for 25-30min to obtain an oil phase;

[0016] (2) dispersing chitosan in acetic acid solution, adding collagen peptide, calcium dodecylbenzenesulfonate and betaine, stirring uniformly at a temperature of 60-65℃ to obtain an aqueous phase;

[0017] (3) adding the aqueous phase of step (2) into the oil phase of step (1), stirring at a speed of 1000-1200rpm, adding glutaraldehyde with a concentration of 25%, stirring uniformly, solidifying, filtering and drying to obtain chitosan microcapsules.

[0018] By adopting the technical scheme, the oil phase is obtained by mixing petroleum ether, modified liquid paraffin and span-80, which serves as the wall material of the chitosan microcapsule and provides a slow release environment for the subsequent use of the core material; the modified liquid paraffin helps to maintain the stability of the substances in the chitosan microcapsule due to its hydrophobicity, changes the physical properties of the wall material, such as increasing flexibility and reducing brittleness, so that the microcapsule is more durable and less likely to break during processing and application.

[0019] The chitosan solution forms the aqueous phase as the core material, which has good biocompatibility, serves as a carrier to wrap active ingredients, controls the release rate, improves the stability of the core material, and helps the subsequent release of active ingredients; the collagen peptide and chitosan are mixed, the coating ability of chitosan improves the stability and bioavailability of collagen peptide, so that the nutrient ingredients are more effectively released, providing the nutrients required for plant growth, helping to improve the water retention capacity and structure of the leaf, and enhancing the water use efficiency and photosynthesis efficiency of the plant, which helps to promote the maturation and color change of the fruit.

[0020] The calcium dodecylbenzenesulfonate has good emulsifying and dispersing effects, helps the chitosan and collagen peptide to be better dispersed, improves the biological activity and plant absorption efficiency thereof in the soil, and helps to subsequently improve the growth of plants; the osmotic regulation and stress resistance enhancement functions of the betaine are combined with the root system promotion and natural antibacterial properties of the chitosan, as a biological stimulant, improves the growth efficiency and disease resistance of crops, improves the internal quality and external morphology of crops, increases the sugar content of fruits, and improves the color and the like; and the osmotic regulation ability of the betaine helps the collagen peptide to be better absorbed by plants, while providing anti-stress and moisturizing benefits, improves the bioavailability of the collagen peptide, so that the core material has a good effect of improving the growth of plants.

[0021] The chitosan microcapsule prepared by cooperation of the oil phase and the water phase encapsulates the active ingredients in the foliar fertilizer, protects them from degradation by environmental factors, ensures slow release on the leaf surface, improves the utilization efficiency of nutrients, controls the release of fertilizer ingredients, so that the nutrients are more accurately absorbed by crops, and the chitosan microcapsule can provide an ideal release environment.

[0022] Optionally, the mass ratio of the chitosan, the collagen peptide and the betaine is 1:0.3-0.5:0.1-0.2.

[0023] By adopting the above technical solution, the mass ratio of the chitosan, the collagen peptide and the betaine is further limited within a certain range, the obtained core material has a better effect of promoting fruit color change, the chitosan, the collagen peptide and the betaine have a synergistic effect, the coating ability of the chitosan improves the stability and bioavailability of the collagen peptide, so that the nutrient ingredients are more effectively released, the nutrients required for plant growth are provided, the osmotic regulation and stress resistance enhancement functions of the betaine are combined with the root system promotion and natural antibacterial properties of the chitosan, the ability helps the collagen peptide to be better absorbed by plants, improves the bioavailability of the collagen peptide, so that the core material has a good effect of improving the growth of plants, and further promotes the color change of fruits.

[0024] Optionally, the preparation method of the modified liquid paraffin comprises the following steps: dispersing paraffin in n-hexane, stirring at a temperature of 70-75℃ for 20-25min, adding nano-SiO2, acrylic acid and a silane coupling agent, and stirring uniformly to obtain the modified liquid paraffin.

[0025] By adopting the technical scheme, the paraffin is dissolved in n-hexane, and the nano-SiO2 is added, the nano-SiO2 can be loaded in the paraffin structure, the mechanical strength, heat resistance and wear resistance of the paraffin system are improved, the durability and waterproofness of the paraffin are improved, and then the mechanical properties of the chitosan wall material are improved, the service life of the chitosan microcapsule is prolonged, the nano-SiO2 helps to improve the plant nutrient absorption efficiency, enhance the physical stability of the fertilizer solution, promote the plant to more effectively utilize the nutrient ingredients in the foliar fertilizer, and promote the fruit color change.

[0026] The acrylic acid is mixed with the paraffin to improve the waterproofness, gloss or reduce the friction of the material surface, improve the stability of the paraffin, make the components in the paraffin system uniformly mixed, the silane coupling agent promotes the uniform dispersion of the paraffin particles, reduces the aggregation, improves the physical properties of the material, such as reducing stress cracking and enhancing flexibility, and the functional groups of the silane coupling agent can help the paraffin to better adhere to the plant surface, and then the chitosan microcapsule prepared subsequently adheres to the plant surface, thereby prolonging the release period of the drug and promoting the growth of the plant; the various components cooperate with each other, not only improve the mechanical properties of the paraffin and improve the mechanical properties of the chitosan wall material, but also promote the growth of the plant and the color change of the fruit.

[0027] Optionally, the mass ratio of the paraffin, the nano-SiO2 and the silane coupling agent is 1:0.5-0.7:0.2-0.4.

[0028] By adopting the technical scheme, the modified paraffin obtained by further limiting the mass ratio of the paraffin, the nano-SiO2 and the silane coupling agent has good mechanical properties, and the mechanical properties of the chitosan microcapsule are improved subsequently, so that the chitosan microcapsule has a long service life, and the time of the foliar fertilizer acting on the plant is prolonged, the paraffin, the nano-SiO2 and the silane coupling agent have a synergistic effect, the nano-SiO2 can be loaded in the paraffin structure, the mechanical strength, heat resistance and wear resistance of the paraffin system are improved, the silane coupling agent promotes the uniform dispersion of the paraffin particles, reduces the aggregation, improves the physical properties of the material, and promotes the growth of the plant and the color change of the fruit subsequently.

[0029] Optionally, the preparation method of the modified wheat shell comprises the following steps:

[0030] (1) crushing the wheat shell, placing it in a hydrochloric acid solution, acidifying, washing with water, filtering, and drying to obtain pretreated wheat shell;

[0031] (2) dispersing the pretreated wheat shell in step (1) in deionized water, stirring at a temperature of 80-85℃ for 10-15min, adding anthocyanin and sodium carboxymethyl cellulose, stirring for 1-2h, filtering, and drying to obtain modified wheat shell.

[0032] By employing the above technical solution, wheat hulls are pretreated with hydrochloric acid solution, resulting in a porous surface that enhances their strength. Anthocyanins can be loaded onto the surface and within the pores of the wheat hulls, working in conjunction with the hulls to improve the efficacy of foliar fertilizers, promote plant photosynthesis, enhance plant resistance to environmental stress, improve leaf absorption performance, promote the absorption and transport of other nutrients within the plant, and consequently improve fruit color. Sodium carboxymethyl cellulose has a certain degree of viscosity, increasing the adhesion between anthocyanins and wheat hulls, allowing anthocyanins to adhere to the surface of the wheat hulls and improving their stability. This facilitates their subsequent action in foliar fertilizers, ensuring that the wheat hulls adhere to the plant surface and are evenly distributed, thereby prolonging nutrient absorption time and improving nutrient utilization efficiency.

[0033] Preferably, the mass ratio of wheat hulls, anthocyanins, and sodium carboxymethyl cellulose is 1:0.4-0.6:0.1-0.3.

[0034] By adopting the above technical solution, the mass ratio of wheat hulls, anthocyanins, and sodium carboxymethyl cellulose is further limited within a certain range, which improves the strength of wheat hulls and helps them to be evenly dispersed in foliar fertilizers, thereby improving the efficacy of foliar fertilizers. Anthocyanins can be loaded on the surface and in the pores of wheat hulls, and sodium carboxymethyl cellulose enables anthocyanins to adhere to the surface of wheat hulls, improving the stability of anthocyanins. Subsequently, wheat hulls adhere to the plant surface, prolonging the nutrient absorption time and improving nutrient utilization efficiency.

[0035] Secondly, this application provides a method for preparing seaweed foliar fertilizer that promotes fruit color change.

[0036] Thirdly, this application provides a method for preparing seaweed foliar fertilizer that promotes fruit color change, and the application of the seaweed foliar fertilizer prepared in grapes, apples, and citrus.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. The components in this application work together to enhance nutrient utilization efficiency, achieve a synergistic effect of nutrients, promote rapid nutrient replenishment, promote internal metabolic processes in the fruit, ensure that the fruit obtains the necessary nutrients during ripening, help synthesize pigments such as carotenoids and anthocyanins, promote fruit color change, and the fertilizer is environmentally friendly, improves soil quality, has a small environmental burden, and meets the standards of green agriculture.

[0039] 2. The seaweed enzymatic hydrolysate in this application is rich in natural growth-promoting substances, such as plant hormones, minerals and trace elements. These components can be quickly absorbed by the leaves, providing additional nutrition to the crop, promoting healthy growth, helping the fruit to ripen healthily, and promoting fruit color change.

[0040] 3. The chitosan microcapsules in this application can encapsulate the active ingredients in foliar fertilizers. By controlling the degradation rate of the capsules, the nutrients can be released slowly, thus prolonging the fertilizer effect, reducing nutrient loss, and improving the efficiency of use. Detailed Implementation

[0041] Example of chitosan microcapsule preparation

[0042] Preparation Example 1-1

[0043] The preparation method of chitosan microcapsules includes the following steps:

[0044] (1) Mix 2 kg of petroleum ether, 10 kg of modified liquid paraffin and 1 kg of Span-80, and stir at 75°C for 30 min to obtain the oil phase;

[0045] (2) Disperse 3 kg of chitosan in 7 L of acetic acid solution with a mass fraction of 10%, add collagen peptides, 0.3 kg of calcium dodecylbenzenesulfonate and betaine, and stir evenly at 65 °C to obtain an aqueous phase;

[0046] (3) Add the aqueous phase from step (2) to the oil phase from step (1), stir at 1200 rpm, add 1 L of glutaraldehyde with a concentration of 25%, stir until uniform, solidify, filter, and dry to obtain chitosan microcapsules.

[0047] The mass ratio of chitosan, collagen peptides and betaine is 1:0.3:0.2.

[0048] The preparation method of modified liquid paraffin includes the following steps: 12 kg of paraffin is dispersed in 16 L of n-hexane, stirred at 75 °C for 25 min, nano-SiO2, 3 kg of acrylic acid and silane coupling agent (using coupling agent KH-570) are added, and stirred evenly to obtain modified liquid paraffin.

[0049] The mass ratio of paraffin, nano-SiO2, and silane coupling agent is 1:0.5:0.4.

[0050] Preparation Examples 1-2

[0051] The difference from Preparation Example 1-1 is that in step (1), the modified liquid paraffin is replaced by an equal amount of liquid paraffin.

[0052] Preparation Examples 1-3

[0053] The difference from preparation example 1-1 is that collagen peptides are not added in step (2).

[0054] Preparation Examples 1-4

[0055] The difference from preparation example 1-1 is that betaine is not added in step (2).

[0056] Preparation Examples 1-5

[0057] The difference from Preparation Example 1-1 is that the mass ratio of chitosan, collagen peptides and betaine is 1:0.5:0.1.

[0058] Preparation Examples 1-6

[0059] The difference from Preparation Example 1-1 is that the mass ratio of chitosan, collagen peptides and betaine is 1:0.1:0.6.

[0060] Preparation Examples 1-7

[0061] The difference from Preparation Example 1-1 is that nano-SiO2 is not added in the preparation method of modified liquid paraffin.

[0062] Preparation Examples 1-8

[0063] The difference from Preparation Example 1-1 is that no silane coupling agent is added in the preparation method of modified liquid paraffin.

[0064] Preparation Examples 1-9

[0065] The difference from Preparation Example 1-1 is that the mass ratio of paraffin, nano-SiO2 and silane coupling agent is 1:0.7:0.2.

[0066] Preparation Examples 1-10

[0067] The difference from Preparation Example 1-1 is that the mass ratio of paraffin, nano-SiO2 and silane coupling agent is 1:0.2:0.8.

[0068] Example of preparation of modified wheat hull

[0069] Preparation Example 2-1

[0070] The method for preparing modified wheat hulls includes the following steps:

[0071] (1) Crush 5 kg of wheat hulls, place them in 7 L of 4% hydrochloric acid solution, acidify, wash with water, filter, and dry to obtain pretreated wheat hulls;

[0072] (2) Disperse the wheat hulls pretreated in step (1) in 10L of deionized water, stir at 85℃ for 15min, add anthocyanins and sodium carboxymethyl cellulose, stir for 2h, filter, and dry to obtain modified wheat hulls.

[0073] The mass ratio of wheat hulls, anthocyanins, and sodium carboxymethyl cellulose is 1:0.4:0.3.

[0074] Preparation Example 2-2

[0075] The difference from preparation example 2-1 is that step (1) is not performed.

[0076] Preparation Examples 2-3

[0077] The difference from preparation example 2-1 is that anthocyanins are not added in step (2).

[0078] Preparation Examples 2-4

[0079] The difference from Preparation Example 2-1 is that sodium carboxymethyl cellulose is not added in step (2).

[0080] Preparation Examples 2-5

[0081] The difference from Preparation Example 2-1 is that the mass ratio of wheat husk, anthocyanins, and sodium carboxymethyl cellulose is 1:0.6:0.1.

[0082] Preparation Examples 2-6

[0083] The difference from Preparation Example 2-1 is that the mass ratio of wheat husk, anthocyanins, and sodium carboxymethyl cellulose is 1:0.1:0.6.

[0084] Example

[0085] Example 1

[0086] A method for preparing seaweed foliar fertilizer to promote fruit color change includes the following steps: mixing seaweed enzymatic hydrolysate, potassium dihydrogen phosphate, amino acids, humic acid, chitosan microcapsules, and modified wheat husks, stirring at 65°C for 2 hours, and allowing to stand to obtain seaweed foliar fertilizer.

[0087] By weight, the contents are: 30 kg of seaweed hydrolysate, 5 kg of potassium dihydrogen phosphate, 20 kg of amino acids, 3 kg of humic acid, 10 kg of chitosan microcapsules, and 5 kg of modified wheat husks.

[0088] Chitosan microcapsules were prepared using Example 1-1, and modified wheat husks were prepared using Example 2-1.

[0089] Example 2

[0090] A method for preparing a seaweed foliar fertilizer to promote fruit color change differs from Example 1 in that, by weight, it contains 40 kg of seaweed enzymatic hydrolysate, 9 kg of potassium dihydrogen phosphate, 25 kg of amino acids, 6 kg of humic acid, 15 kg of chitosan microcapsules, and 8 kg of modified wheat husks.

[0091] Example 3

[0092] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-2.

[0093] Example 4

[0094] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-3.

[0095] Example 5

[0096] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-4.

[0097] Example 6

[0098] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-5.

[0099] Example 7

[0100] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-6.

[0101] Example 8

[0102] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-7.

[0103] Example 9

[0104] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-8.

[0105] Example 10

[0106] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-9.

[0107] Example 11

[0108] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the chitosan microcapsules are prepared using Examples 1-10.

[0109] Example 12

[0110] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the modified wheat husk is prepared using Example 2-2.

[0111] Example 13

[0112] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the modified wheat husk is prepared using Examples 2-3.

[0113] Example 14

[0114] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the modified wheat husk is prepared using Examples 2-4.

[0115] Example 15

[0116] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the modified wheat husk is prepared using Examples 2-5.

[0117] Example 16

[0118] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that the modified wheat husk is prepared using Examples 2-6.

[0119] Comparative Example

[0120] Comparative Example 1

[0121] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that chitosan microcapsules are not added.

[0122] Comparative Example 2

[0123] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that an equal amount of chitosan is used instead of chitosan microcapsules.

[0124] Comparative Example 3

[0125] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that modified wheat husks are not added.

[0126] Comparative Example 4

[0127] A method for preparing a seaweed foliar fertilizer that promotes fruit color change differs from Example 1 in that an equal amount of wheat hulls is used to replace modified wheat hulls.

[0128] Performance testing

[0129] The chitosan microcapsules prepared in Examples 1-10 were subjected to performance testing.

[0130] Mechanical strength test: The microcapsules in the examples were tableted using a tablet press at a pressure of 6 MPa, and the breakage of the microcapsules was observed. The lower the breakage rate, the higher the mechanical strength of the microcapsules.

[0131] Encapsulation efficiency determination: Encapsulation efficiency refers to the ratio of the content of the core material composition encapsulated in the microcapsule to the total amount of the core material composition added during encapsulation. The higher the encapsulation efficiency, the greater the amount of core material encapsulated, and the better the effect.

[0132] Encapsulation rate = (total mass of core material composition in microcapsules - mass of core material composition on the surface of microcapsules) / total mass of core material composition in microcapsules × 100%. The test results are shown in Table 1.

[0133] Table 1 Test data for the examples and comparative examples

[0134]

[0135] The seaweed foliar fertilizers prepared in Examples 1-16 and Comparative Examples 1-4 were subjected to performance tests.

[0136] Method for determining color change rate: After the application of seaweed foliar fertilizer, select fruit trees with different treatments for a continuous 5-meter length at the time of fruit harvest, observe the color change of the fruit, record the number of fruits with uniform color change and the number of fruits with uneven color change, and calculate the color change rate; test crop: apple.

[0137] The seaweed foliar fertilizer prepared in this application is used for drip irrigation during the apple ripening period. The dilution ratio is 500 times (by weight), applied once every 7 days for a total of 2 applications, with each application being 5 kg / mu (dry weight of fertilizer), for a total application of 10 kg / mu. When the apples in the experimental field begin to be marketed, the ripening rate of the apples is measured. During the apple harvest period, the apple weight is continuously measured, and the ripening rate, average sugar content, average diameter, and rate of high-quality fruit are determined.

[0138] Apples with a diameter of 90mm or greater are classified as Grade 1, those between 85-90mm as Grade 2, those between 80-85mm as Grade 3, those between 75-80mm as Grade 4, and those between 70-75mm as Grade 5. Superior quality apples are those with a diameter of 70mm or larger. Test results are shown in Table 2.

[0139] Table 2 Test data for the examples and comparative examples

[0140]

[0141]

[0142] Based on the preparation examples and the data in Table 1, it can be seen that the chitosan microcapsules prepared in Preparation Example 1 have good mechanical properties, with a breakage rate of 2.1% and an encapsulation rate of 90.2%. This indicates that the microcapsules prepared in this application have good mechanical properties and can subsequently adhere to the plant leaf surface, ensuring slow release on the leaf surface, improving nutrient utilization efficiency, controlling the release of fertilizer components, and enabling nutrients to be absorbed more accurately by crops.

[0143] In Preparation Example 2, the modified liquid paraffin was replaced with an equal amount of liquid paraffin. As shown in Table 1, the breakage rate was 4.3% and the encapsulation rate was 81.2%, indicating that the modified liquid paraffin of this application has better mechanical properties and adhesion, which can further improve the corresponding properties of chitosan microcapsules.

[0144] Preparation Examples 3-6 and 9 had little effect on the mechanical properties of chitosan microcapsules. Preparation Examples 7-8 and 10, respectively, showed no addition of nano-SiO2 and silane coupling agent, and different mass ratios of paraffin, nano-SiO2, and silane coupling agent. It can be seen that the breakage rate and encapsulation rate decreased to varying degrees, indicating that paraffin, nano-SiO2, and silane coupling agent have a synergistic effect. Nano-SiO2 can be loaded into the paraffin structure, improving the mechanical strength, heat resistance, and wear resistance of the paraffin system. The silane coupling agent promotes the uniform dispersion of paraffin particles, reduces aggregation, and improves the physical properties of the material, thereby affecting the corresponding properties of chitosan microcapsules.

[0145] Based on the examples and the data in Table 2, it can be seen that the seaweed foliar fertilizers prepared in Examples 1-2, 6, 10, and 15 have good medicinal properties, improve fruit color change rate, and increase the rate of high-quality fruit. Among them, the color change rate of Example 1 is 98%, the relative increase in color change is 16.7%, the average sugar content is 15.9, the average diameter is 90.1 mm, and the rate of high-quality fruit is 97%. This indicates that the various components in this application work together to achieve a synergistic effect of nutrients, promote rapid nutrient replenishment, promote internal metabolic processes in the fruit, and promote fruit color change. Moreover, this fertilizer is environmentally friendly, improves soil quality, has a low environmental burden, and meets the standards of green agriculture.

[0146] In Example 3, the modified liquid paraffin was replaced with an equal amount of liquid paraffin in the preparation method of chitosan microcapsules. As shown in Table 2, the fruit color change rate, the increase in relative color change, the average sugar content, the average diameter, and the rate of high-quality fruit all decreased. This indicates that the chitosan microcapsules prepared by the modified liquid paraffin in this application have better mechanical properties, which can improve the release efficiency of chitosan microcapsules, ensure that the fruit fully absorbs nutrients, and improve the overall performance of fruit ripening.

[0147] In the preparation methods of chitosan microcapsules in Examples 4-5 and Example 7, collagen peptides and betaine were not added, and the mass ratio of chitosan, collagen peptides, and betaine was changed, respectively. As shown in Table 2, the fruit color change rate, relative increase in color change, average sugar content, average diameter, and rate of high-quality fruit all decreased to varying degrees. This indicates that the combination of betaine's osmotic regulation and stress resistance enhancement functions with chitosan's root promotion and natural antibacterial properties can help collagen peptides be better absorbed by plants, improve the bioavailability of collagen peptides, and make the core material have a better effect on improving plant growth, thereby promoting fruit color change.

[0148] In the preparation methods of modified liquid paraffin in Examples 8-9 and Example 11, nano-SiO2 and silane coupling agents were not added, and the mass ratio of paraffin, nano-SiO2 and silane coupling agent was not specified. As shown in Table 2, the fruit color change rate, relative increase in color change, average sugar content, average diameter and rate of high-quality fruit all decreased to varying degrees. This indicates that paraffin, nano-SiO2 and silane coupling agent have a synergistic effect, affecting the mechanical properties of the chitosan microcapsule wall material, and thus affecting the drug effect of chitosan microcapsules, as well as the growth of plants and the color change of fruits.

[0149] In the preparation methods of modified wheat hulls in Examples 12-14 and Example 16, step (1) was omitted, anthocyanins were not added, sodium carboxymethyl cellulose was not added, and the mass ratio of wheat hulls, anthocyanins, and sodium carboxymethyl cellulose was changed. As shown in Table 2, the fruit color change rate, relative increase in color change, average sugar content, average diameter, and rate of high-quality fruit all decreased to varying degrees. This indicates that anthocyanins can be loaded on the surface and pores of wheat hulls. Sodium carboxymethyl cellulose makes anthocyanins adhere to the surface of wheat hulls, improving the stability of anthocyanins. Subsequently, wheat hulls adhere to the plant surface, prolonging the nutrient absorption time, improving nutrient utilization efficiency, and thus improving fruit quality.

[0150] Compared with Example 1, which did not add chitosan microcapsules, Table 2 shows that the fruit color change rate, the increase in color change, the average sugar content, the average diameter, and the rate of high-quality fruit all decreased significantly. This indicates that chitosan microcapsules can encapsulate the active ingredients in foliar fertilizers and achieve slow release of nutrients by controlling the degradation rate of the capsules. This can prolong the fertilizer effect, reduce nutrient loss, improve the efficiency of use, and thus improve the overall quality of the fruit.

[0151] Comparative Example 2 replaced chitosan microcapsules with an equal amount of chitosan. As shown in Table 2, the fruit color change rate, relative increase in color change, average sugar content, average diameter, and rate of high-quality fruit all decreased significantly, but the effect was better than that of Comparative Example 1. This indicates that the chitosan microcapsules prepared in this application have better comprehensive performance, thereby improving the corresponding quality of the fruit.

[0152] In Comparative Example 3, without the addition of modified wheat hulls, Table 2 shows that the fruit color change rate, relative increase in color change, average sugar content, average diameter, and rate of high-quality fruit all decreased significantly. This indicates that modified wheat hulls, as a carrier for foliar fertilizer, improve the uniformity of foliar fertilizer application, allowing it to better adhere to the leaf surface, prolonging the contact time of nutrients, improving absorption efficiency, and thus improving the corresponding quality of the fruit.

[0153] Comparative Example 4 involved replacing the modified wheat hulls with an equal amount of wheat hulls. As shown in Table 2, the fruit color change rate, relative increase in color change, average sugar content, average diameter, and rate of high-quality fruit all decreased significantly. This indicates that the modified wheat hulls in this application have superior adhesion properties, thereby improving the corresponding properties of seaweed foliar fertilizer and subsequently improving the quality of the fruit.

[0154] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a seaweed foliar fertilizer that promotes fruit color change, characterized in that, The process includes the following steps: mixing seaweed enzymatic hydrolysate, potassium dihydrogen phosphate, amino acids, humic acid, chitosan microcapsules, and modified wheat husks, stirring at 60-65℃ for 1-2 hours, and allowing to stand to obtain seaweed foliar fertilizer. The method for preparing the chitosan microcapsules includes the following steps: (1) Mix petroleum ether, modified liquid paraffin and Span-80, and stir at 70-75℃ for 25-30 min to obtain the oil phase; (2) Chitosan was dispersed in acetic acid solution, and collagen peptides, calcium dodecylbenzenesulfonate and betaine were added. The mixture was stirred evenly at 60-65℃ to obtain an aqueous phase. (3) Add the aqueous phase from step (2) to the oil phase from step (1), stir at a speed of 1000-1200 rpm, add glutaraldehyde at a concentration of 25%, stir evenly, solidify, filter, and dry to obtain chitosan microcapsules. The method for preparing the modified liquid paraffin includes the following steps: dispersing paraffin in n-hexane, stirring at 70-75℃ for 20-25 min, adding nano-SiO2, acrylic acid and silane coupling agent, stirring evenly to obtain modified liquid paraffin; The method for preparing the modified wheat hull includes the following steps: (1) Crush the wheat hulls, place them in hydrochloric acid solution, acidify, wash with water, filter, and dry to obtain pretreated wheat hulls; (2) Disperse the wheat hulls pretreated in step (1) in deionized water, stir at 80-85℃ for 10-15 min, add anthocyanins and sodium carboxymethyl cellulose, stir for 1-2 h, filter, dry, and obtain modified wheat hulls.

2. The method for preparing a seaweed foliar fertilizer to promote fruit color change according to claim 1, characterized in that, By weight, the composition is as follows: 30-40 parts seaweed hydrolysate, 5-9 parts potassium dihydrogen phosphate, 20-25 parts amino acids, 3-6 parts humic acid, 10-15 parts chitosan microcapsules, and 5-8 parts modified wheat husk.

3. The method for preparing a seaweed foliar fertilizer to promote fruit color change according to claim 1, characterized in that, The mass ratio of chitosan, collagen peptides and betaine is 1:0.3-0.5:0.1-0.

2.

4. The method for preparing a seaweed foliar fertilizer to promote fruit color change according to claim 1, characterized in that, The mass ratio of the paraffin wax, nano-SiO2, and silane coupling agent is 1:0.5-0.7:0.2-0.

4.

5. The method for preparing a seaweed foliar fertilizer to promote fruit color change according to claim 1, characterized in that, The mass ratio of wheat hulls, anthocyanins, and sodium carboxymethyl cellulose is 1:0.4-0.6:0.1-0.

3.

6. The seaweed foliar fertilizer prepared according to any one of claims 1-5, which is a method for preparing seaweed foliar fertilizer to promote fruit color change.

7. The application of the seaweed foliar fertilizer prepared according to any one of claims 1-5 in grapes, apples, and citrus.

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