Composite seaweed fertilizer and application thereof

Abstract

The present application relates to a kind of composite seaweed fertilizer and its application, belong to the technical field of agricultural chemicals.The present application is by using pyridine ester compound and seaweed fertilizer, both have synergistic effect, and the growth of cucumber and the improvement of fruit quality have significant promotion effect.The composite seaweed fertilizer of the present application can significantly improve the yield of cucumber, melon length, transverse diameter, flesh thickness and the content of protein, total sugar, fat, vitamin B2, vitamin C, iron element and calcium element.

Description

Technical Field

[0001] This invention relates to a compound seaweed fertilizer and its application, belonging to the field of agricultural chemical technology. Background Technology

[0002] Seaweed fertilizer, an organic fertilizer made from natural seaweed, contains many trace elements such as iodine, manganese, and titanium, which are rare in terrestrial plants, as well as seaweed polysaccharides. It also contains various plant-derived endogenous hormones, including auxins, cytokinins, gibberellins, abscisic acid, and ethylene. These endogenous hormones can promote plant growth and increase yield.

[0003] Cucumber is an important vegetable crop, also known as gourd or green cucumber. Its stems and branches are elongated, ridged, and covered with white, rough hairs. The tendrils are thin, and the petioles are slightly rough and covered with rough hairs. The leaves are broadly ovate-cordate, membranous, with triangular, toothed lobes. The fruit is oblong or cylindrical, yellowish-green when ripe, with a rough surface. The seeds are small, narrowly ovate, white, without edges, and nearly acute at both ends. Cucumbers have good edible and medicinal value.

[0004] As living standards improve, people's demands for the quality of vegetable products are also increasing. They not only require attractive appearance and good flavor, but also rich, balanced nutrients and high health benefits. While combining seaweed fertilizer with conventional plant growth regulators can improve plant yield and quality to some extent, the improvement is limited. Summary of the Invention

[0005] The purpose of this invention is to provide a compound seaweed fertilizer and its application to improve cucumber yield and fruit quality.

[0006] This invention provides a compound seaweed fertilizer, comprising a pyridine ester compound and seaweed fertilizer, wherein the mass of the pyridine ester compound is 1.5-2.5% of the mass of the seaweed fertilizer; the structure of the pyridine ester compound is as follows:

[0007]

[0008] Wherein, R is a C1~C3 alkylene group;

[0009] The preparation method of the seaweed fertilizer is as follows: mix and crush the algae, kelp, grapefruit peel and water to obtain a crushed liquid; then enzymatically hydrolyze the crushed liquid to obtain the seaweed fertilizer; the mass ratio of algae, kelp and grapefruit peel is 3~4:3~4:1~1.5.

[0010] Preferably, R is ethylene.

[0011] Preferably, the pyridine ester compound is prepared by reacting 2-propanolpyridine with an acyl chloride compound, wherein the acyl chloride compound is 3-chloropropionyl chloride, 4-chlorobutyryl chloride or chloroacetyl chloride, and the molar ratio of 2-propanolpyridine to the acyl chloride compound is 1:1.1~1.2.

[0012] Preferably, the mass ratio of the algae, kelp, grapefruit peel, and water is 3~4:3~4:1~1.5:10; the compound enzyme used in the enzymatic hydrolysis consists of protease, pectinase, oxidoreductase, and cellulase in a mass ratio of 20:8:15:35; the mass ratio of the lysate to the compound enzyme is 100:1; the pH during enzymatic hydrolysis is 6.5~7.5; the temperature is 35~40℃; and the time is 70~80h.

[0013] Application of a compound seaweed fertilizer as described above.

[0014] Preferably, the application includes the following steps: spraying the pyridine ester compound and the seaweed fertilizer in the compound seaweed fertilizer onto the plant leaves in the form of a diluted solution.

[0015] Preferably, the plant is a cucumber; the spraying is carried out after the cucumber seedlings have recovered from transplanting, with the seaweed fertilizer diluted solution sprayed once every 15-17g, and the amount sprayed each time being 600-700kg / hm². 2 Spray cucumber seedlings with a diluted pyridine ester compound once, 18-20 days after transplanting, at a rate of 600-700 kg / hm². 2 The seaweed fertilizer dilution is prepared by mixing seaweed fertilizer and water at a mass ratio of 1~1.5g:1.5kg, and the pyridine ester compound dilution is prepared by mixing pyridine ester compound and water at a mass ratio of 0.015g:1.5kg.

[0016] Preferably, the application is to increase cucumber yield.

[0017] Preferably, the application is to increase the length, diameter, and flesh thickness of the cucumber.

[0018] Preferably, the application is to increase the content of protein, total sugar, fat, vitamin B2, vitamin C, iron and calcium in cucumbers.

[0019] Compared to existing technologies, the beneficial effects of this invention are as follows: By combining pyridine ester compounds and seaweed fertilizer, this invention achieves a synergistic effect, significantly improving the growth and fruit quality of cucumbers. The compound seaweed fertilizer of this invention can significantly increase cucumber yield, length, diameter, flesh thickness, and the content of protein, total sugar, fat, vitamin B2, vitamin C, iron, and calcium. Attached Figure Description

[0020] Figure 1 This is the 1H NMR spectrum of the pyridine ester compound prepared in Example 1 of this invention. Detailed Implementation

[0021] The following examples are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the present invention. Example

[0022] The compound seaweed fertilizer of this embodiment includes pyridine ester compounds and seaweed fertilizer, wherein the mass of the pyridine ester compounds is 1.5% of the mass of the seaweed fertilizer. The preparation method of the seaweed fertilizer is as follows: *Leptochloa crus-galli*, kelp, grapefruit peel, and water are mixed in a mass ratio of 3:4:1:10 and then crushed to obtain a crushed liquid. Then, the crushed liquid and a compound enzyme (composed of protease, pectinase, oxidoreductase, and cellulase in a mass ratio of 20:8:15:35, all commercially available) are added to a mixing tank in a mass ratio of 100:1 for enzymatic hydrolysis. The pH during enzymatic hydrolysis is 6.5, the temperature is 35°C, and the time is 70 hours. After enzymatic hydrolysis, the seaweed fertilizer is obtained.

[0023] The preparation method of pyridine esters is as follows: 2-propanol pyridine and dichloromethane are added to a reaction vessel and stirred until homogeneous to obtain a 20% (w / w) 2-propanol pyridine solution. The temperature of the material in the reaction vessel is then adjusted to -7°C, stirring is started, and an acyl chloride compound is added dropwise to the reaction vessel. After the addition is complete, triethylamine is added to the reaction vessel, and the temperature of the material in the reaction vessel is adjusted to room temperature. The reaction is continued with stirring for 5 hours. Then, 20% (w / w) ammonia water is added to the reaction vessel, stirred for 30 minutes, allowed to stand for separation, and the organic phase is rotary evaporated to obtain a concentrated solution. The concentrated solution is then purified by column chromatography (the eluent used for column chromatography is a mixture of ethyl acetate and petroleum ether with a volume ratio of 3:7) to obtain pyridine esters; wherein the acyl chloride compound is 3-chloropropionyl chloride, and the molar ratio of 2-propanol pyridine, the acyl chloride compound, and nitrogen in the ammonia water is 1:1.1:1.4. The 1H NMR spectrum of the pyridine esters prepared in this example is shown below. Figure 1 As shown, the chemical structure is as follows:

[0024]

[0025] Example 2

[0026] The compound seaweed fertilizer of this embodiment includes pyridine ester compounds and seaweed fertilizer, wherein the mass of the pyridine ester compounds is 2.0% of the mass of the seaweed fertilizer; wherein the preparation method of the seaweed fertilizer is as follows: *Leptochloa crus-galli*, kelp, grapefruit peel, and water are mixed in a mass ratio of 4:3:1.2:10 and then crushed to obtain a crushed liquid; then the crushed liquid and a compound enzyme (the compound enzyme consists of protease, pectinase, oxidoreductase, and cellulase in a mass ratio of 20:8:15:35, all of which are commercially available products) are added to a mixing tank in a mass ratio of 100:1 for enzymatic hydrolysis. The pH during enzymatic hydrolysis is 7, the temperature is 37°C, and the time is 75 hours. After the enzymatic hydrolysis is completed, the seaweed fertilizer is obtained.

[0027] The preparation method of pyridine esters is as follows: 2-propanol pyridine and dichloromethane are added to a reaction vessel and stirred until homogeneous to obtain a 25% (w / w) 2-propanol pyridine solution. The temperature of the material in the reaction vessel is then adjusted to -4°C, stirring is started, and an acyl chloride compound is added dropwise to the reaction vessel. After the addition is complete, triethylamine is added to the reaction vessel, and the temperature of the material in the reaction vessel is adjusted to room temperature. The reaction is continued with stirring for 6 hours. Then, 20% (w / w) ammonia water is added to the reaction vessel, stirred for 40 minutes, allowed to stand for separation, and the organic phase is rotary evaporated to obtain a concentrated solution. The concentrated solution is then purified by column chromatography (the eluent used for column chromatography is a mixture of ethyl acetate and petroleum ether with a volume ratio of 3:7) to obtain pyridine esters; wherein the acyl chloride compound is 3-chloropropionyl chloride, and the molar ratio of 2-propanol pyridine, the acyl chloride compound, and nitrogen in the ammonia water is 1:1.1:1.5. The chemical structure of the pyridine esters prepared in this example is shown in the following formula:

[0028]

[0029] Example 3

[0030] The compound seaweed fertilizer of this embodiment includes pyridine ester compounds and seaweed fertilizer, wherein the mass of the pyridine ester compounds is 2.5% of the mass of the seaweed fertilizer. The preparation method of the seaweed fertilizer is as follows: *Leptochloa crus-galli*, kelp, grapefruit peel, and water are mixed in a mass ratio of 4:4:1.5:10 and then crushed to obtain a crushed liquid. Then, the crushed liquid and a compound enzyme (composed of protease, pectinase, oxidoreductase, and cellulase in a mass ratio of 20:8:15:35, all commercially available) are added to a mixing tank in a mass ratio of 100:1 for enzymatic hydrolysis. The pH during enzymatic hydrolysis is 7.5, the temperature is 40°C, and the time is 80 hours. After enzymatic hydrolysis, the seaweed fertilizer is obtained.

[0031] The preparation method of pyridine esters is as follows: 2-propanol pyridine and dichloromethane are added to a reaction vessel and stirred until homogeneous to obtain a 30% (w / w) 2-propanol pyridine solution. The temperature of the material in the reaction vessel is then adjusted to 0°C, stirring is started, and an acyl chloride compound is added dropwise to the reaction vessel. After the addition is complete, triethylamine is added to the reaction vessel, and the temperature of the material in the reaction vessel is adjusted to room temperature. The reaction is continued with stirring for 8 hours. Then, 20% (w / w) ammonia water is added to the reaction vessel, stirred for 45 minutes, allowed to stand for separation, and the organic phase is rotary evaporated to obtain a concentrated solution. The concentrated solution is then purified by column chromatography (the eluent used for column chromatography is a mixture of ethyl acetate and petroleum ether with a volume ratio of 3:7) to obtain pyridine esters; wherein the acyl chloride compound is 3-chloropropionyl chloride, and the molar ratio of 2-propanol pyridine, the acyl chloride compound, and nitrogen in the ammonia water is 1:1.2:1.5. The chemical structure of the pyridine esters prepared in this example is shown in the following formula:

[0032]

[0033] Example 4

[0034] The only difference between the compound seaweed fertilizer of this embodiment and the compound seaweed fertilizer of Example 1 is that the acyl chloride compound in the preparation method of the pyridine ester compound in this embodiment is 4-chlorobutyryl chloride. Example

[0035] The only difference between the compound seaweed fertilizer of this embodiment and the compound seaweed fertilizer of Example 1 is that the acyl chloride compound in the preparation method of the pyridine ester compound in the compound seaweed fertilizer of this embodiment is chloroacetyl chloride.

[0036] Comparative Example 1

[0037] The only difference between the compound seaweed fertilizer in this comparative example and the compound seaweed fertilizer in Example 1 is that the pyridine esters in this comparative example are replaced with amino esters.

[0038] Comparative Example 2

[0039] The only difference between the compound seaweed fertilizer in this comparative example and the compound seaweed fertilizer in Example 1 is that the acyl chloride compound in the preparation method of the pyridine ester compound in this comparative example is propionyl chloride.

[0040] Comparative Example 3

[0041] The only difference between the compound seaweed fertilizer in this comparative example and the compound seaweed fertilizer in Example 1 is that the acyl chloride compound in the preparation method of the pyridine ester compound in this comparative example is butyryl chloride.

[0042] Comparative Example 4

[0043] The only difference between the compound seaweed fertilizer in this comparative example and the compound seaweed fertilizer in Example 1 is that the preparation method of the seaweed fertilizer in this comparative example is as follows: *Leptochloa crus-galli*, kelp, and water are mixed in a mass ratio of 3.5:4.5:10 and then crushed to obtain a crushed liquid. Then, the crushed liquid and a compound enzyme (composed of protease, pectinase, oxidoreductase, and cellulase in a mass ratio of 20:8:15:35, all commercially available) are added to a mixing tank in a mass ratio of 100:1 for enzymatic hydrolysis. The pH during enzymatic hydrolysis is 6.5, the temperature is 35°C, and the time is 70 hours. After enzymatic hydrolysis, the seaweed fertilizer is obtained.

[0044] Comparative Example 5

[0045] The only difference between the compound seaweed fertilizer in this comparative example and the compound seaweed fertilizer in Example 1 is that the preparation method of the seaweed fertilizer in this comparative example is as follows: grapefruit peel and water are mixed at a mass ratio of 8:10 and then crushed to obtain a crushed liquid; then the crushed liquid and a compound enzyme (the compound enzyme is composed of protease, pectinase, oxidoreductase and cellulase in a mass ratio of 20:8:15:35, and protease, pectinase, oxidoreductase and cellulase are all commercially available products) are added to a mixing tank at a mass ratio of 100:1 for enzymatic hydrolysis. The pH during enzymatic hydrolysis is 6.5, the temperature is 35℃, and the time is 70h. After the enzymatic hydrolysis is completed, the seaweed fertilizer is obtained.

[0046] Experimental Example

[0047] This experimental example is used to evaluate the effects of the compound seaweed fertilizers of each embodiment and comparative example on cucumber yield, fruit appearance, and nutrient composition of the fruit.

[0048] The experiment was conducted in a high-yield experimental field. Soil fertility parameters were as follows: organic matter 15.11 g / kg, available nitrogen 45.83 mg / kg, available phosphorus (P2O5) 55.21 mg / kg, and available potassium (K2O) 50.46 mg / kg. The Yuexiu No. 1 cucumber variety was used. Base fertilizer was applied to the experimental field before the experiment. A total of 13 treatments were conducted, with 3 plots randomly selected from the experimental field for each treatment. Each plot had an area of ​​20 m². 2 Protection lines are set up, and each community is managed in the same way.

[0049] Treatment 1 was experimental group 1. Treatment method: Starting from the time cucumber seedlings recovered after transplanting, a diluted seaweed fertilizer solution from the compound seaweed fertilizer of Example 1 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from the compound seaweed fertilizer of Example 1 with 1.5kg of water), for a total of 3 applications, with an application rate of 600kg / hm² each time. 2The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine ester compounds from the compound seaweed fertilizer of Example 1 (the diluted solution of pyridine ester compounds is prepared by mixing 0.015g of pyridine ester compounds from the compound seaweed fertilizer of Example 1 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0050] Treatment 2 was experimental group 2. Treatment method: Starting from the time cucumber seedlings recovered after transplanting, a diluted seaweed fertilizer solution from the compound seaweed fertilizer of Example 2 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from the compound seaweed fertilizer of Example 2 with 1.5kg of water), for a total of 3 applications, with each application rate being 600kg / hm². 2 The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine ester compounds from the compound seaweed fertilizer of Example 2 (the diluted solution of pyridine ester compounds is prepared by mixing 0.015g of pyridine ester compounds from the compound seaweed fertilizer of Example 2 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0051] Treatment 3 was experimental group 3. Treatment method: Starting from the time cucumber seedlings recovered after transplanting, a diluted seaweed fertilizer solution from the compound seaweed fertilizer of Example 3 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from the compound seaweed fertilizer of Example 3 with 1.5kg of water), for a total of 3 applications, with each application rate of 600kg / hm². 2 The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine ester compounds from the compound seaweed fertilizer of Example 3 (the diluted solution of pyridine ester compounds is prepared by mixing 0.015g of pyridine ester compounds from the compound seaweed fertilizer of Example 3 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0052] Treatment 4 was experimental group 4. Treatment method: Starting from the time cucumber seedlings recovered after transplanting, a diluted seaweed fertilizer solution from the compound seaweed fertilizer of Example 4 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from the compound seaweed fertilizer of Example 4 with 1.5kg of water), for a total of 3 applications, with each application rate being 600kg / hm². 2The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine ester compounds from the compound seaweed fertilizer of Example 4 (the diluted solution of pyridine ester compounds is prepared by mixing 0.015g of pyridine ester compounds from the compound seaweed fertilizer of Example 4 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0053] Treatment 5 was experimental group 5. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from the compound seaweed fertilizer of Example 5 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of the seaweed fertilizer from Example 5 with 1.5kg of water), for a total of 3 applications, with each application rate being 600kg / hm². 2 The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine ester compounds from the compound seaweed fertilizer of Example 5 (the diluted solution of pyridine ester compounds is prepared by mixing 0.015g of pyridine ester compounds from the compound seaweed fertilizer of Example 5 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0054] Treatment 6 served as control group 1. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from the compound seaweed fertilizer of control group 1 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from control group 1 with 1.5kg of water), for a total of 3 applications, with each application rate of 600kg / hm². 2 The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of amino ester from the compound seaweed fertilizer of Comparative Example 1 (the diluted solution of amino ester is prepared by mixing 0.015g of amino ester with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0055] Treatment 7 served as control group 2. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from control group 2 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from control group 2 with 1.5kg of water), for a total of 3 applications. Each application rate was 600kg / hm². 2The application method is to spray it on the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine esters from the compound seaweed fertilizer of Comparative Example 2 (the diluted solution of pyridine esters was prepared by mixing 0.015g of pyridine esters from the compound seaweed fertilizer of Comparative Example 2 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0056] Treatment 8 served as control group 3. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from control group 3 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from control group 3 with 1.5kg of water), for a total of 3 applications. Each application rate was 600kg / hm². 2 The application method is to spray it onto the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine esters from the compound seaweed fertilizer of Comparative Example 3 (the diluted solution of pyridine esters was prepared by mixing 0.015g of pyridine esters from the compound seaweed fertilizer of Comparative Example 3 with 1.5kg of water), at a rate of 600kg / hm². 2 The application method is to spray it onto the cucumber leaves.

[0057] Treatment 9 served as control group 4. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from control group 4 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from control group 4 with 1.5kg of water), for a total of 3 applications. Each application rate was 600kg / hm². 2 The application method is to spray it on the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine esters from the compound seaweed fertilizer of Comparative Example 4 (the diluted solution of pyridine esters was prepared by mixing 0.015g of pyridine esters from the compound seaweed fertilizer of Comparative Example 4 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0058] Treatment 10 served as control group 5. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from control group 5 was applied every 15 days (the diluted seaweed fertilizer solution was prepared by mixing 1g of seaweed fertilizer from control group 5 with 1.5kg of water), for a total of 3 applications. Each application rate was 600kg / hm². 2The application method is to spray it on the cucumber leaves; and on the 20th day after the cucumber seedlings have recovered from transplanting, apply a diluted solution of pyridine esters from the compound seaweed fertilizer of Comparative Example 5 (the diluted solution of pyridine esters is prepared by mixing 0.015g of pyridine esters from the compound seaweed fertilizer of Comparative Example 5 with 1.5kg of water), at a rate of 600kg / hm. 2 The application method is to spray it onto the cucumber leaves.

[0059] Treatment 11 served as the seaweed fertilizer control group. Treatment method: Starting after cucumber seedling establishment, a diluted seaweed fertilizer solution from Example 1 (prepared by mixing 1g of seaweed fertilizer from Example 1 with 1.5kg of water) was applied every 15 days for a total of 3 applications, with each application rate being 600kg / hm². 2 The application method is to spray it onto the cucumber leaves.

[0060] Treatment 12 served as the pyridine ester compound control group. Treatment method: On the 20th day after cucumber transplanting and seedling establishment, a diluted solution of the pyridine ester compound from the compound seaweed fertilizer of Example 1 was applied once (the diluted solution was prepared by mixing 0.015g of the pyridine ester compound from the compound seaweed fertilizer of Example 1 with 1.5kg of water), at a rate of 600kg / hm². 2 The application method is to spray it onto the cucumber leaves.

[0061] Treatment 13 served as the water control group. Treatment method: Starting after cucumber seedling establishment, water was applied every 15 days for a total of 3 applications, with each application rate being 600 kg / hm². 2 The application method is to spray it onto the cucumber leaves; and apply it once with clean water on the 20th day after the cucumber seedlings have recovered from transplanting, at a rate of 600 kg / hm². 2 The application method is to spray it onto the cucumber leaves.

[0062] During the experiment, the yield, length, diameter, flesh thickness, and content of protein, total sugar, fat, vitamin B2, vitamin C, iron, and calcium in cucumbers were statistically analyzed under different treatments. Cucumber yield was defined as the yield from the start of harvest to 60 days later. Protein content was determined using the Kjeldahl method according to standard GB 5009.5-85; fat content was determined using the Soxhlet extraction method according to standard GB 5009.6-85; total sugar content was determined using the potassium permanganate titration method according to standard GB 5009.7-85; vitamin B2 content was determined using fluorescence spectrometry; vitamin C content was determined using the 2,6-dichlorophenolindophenol method; and iron and calcium content were determined using inductively coupled plasma atomic emission spectrometry.

[0063] When determining cucumber yield, the average yield of the three plots corresponding to each treatment was used as the final experimental result. When determining cucumber length, diameter, flesh thickness, and the content of protein, total sugar, fat, vitamin B2, vitamin C, iron, and calcium, ten cucumbers were randomly selected from the harvested cucumbers of each treatment for measurement, and the average value of these measurements was used as the final experimental result. The experimental results are shown in Tables 1 and 2.

[0064] Table 1. Effects of compound seaweed fertilizers in each example and comparative example on cucumber yield and fruit appearance.

[0065]

[0066] Note: Different lowercase letters in the same column indicate differences at the 5% significance level.

[0067] Table 2. Effects of compound seaweed fertilizer on nutrient composition of cucumber fruits in each example and comparative example.

[0068]

[0069] Note: Different lowercase letters in the same column indicate differences at the 5% significance level.

[0070] As shown in Tables 1 and 2, compared with using seaweed fertilizer dilution or pyridine ester compound dilution alone, the compound seaweed fertilizer of the present invention can significantly increase the yield, length, diameter, flesh thickness, and content of protein, total sugar, fat, vitamin B2, vitamin C, iron, and calcium in cucumbers. This proves that the seaweed fertilizer and the pyridine ester compound synthesized in the present invention have a synergistic effect and significantly improve the growth and fruit quality of cucumbers.

[0071] Furthermore, the comparison results of treatments 1, 4, and 5 show that when the acyl chloride compound used in the preparation of pyridine esters is replaced with 4-chlorobutyryl chloride or chloroacetyl chloride, the change in the carbon chain length on one side of the ester bond may alter the lipophilicity and hydrophilicity of the pyridine esters, affecting their function and leading to a decrease in cucumber yield and quality.

[0072] Finally, treatments 1 and 6-8 show that replacing pyridine esters with conventional amino esters or replacing the acyl chlorides used in the preparation of pyridine esters with propionyl chloride or butyryl chloride weakens the effect of pyridine esters due to the lack of chlorine, leading to a significant decrease in cucumber yield and quality. Treatments 1 and 9-10 show that seaweed organic fertilizer prepared using *Alternanthera philoxeroides*, kelp, and pomelo peel simultaneously improves cucumber yield and quality more effectively than organic fertilizer prepared using *Alternanthera philoxeroides*, kelp, or pomelo peel alone. Treatments 1 and 11-12 show that treating cucumbers with seaweed fertilizer or pyridine esters alone reduces both yield and quality, further demonstrating the synergistic effect of the seaweed fertilizer and synthesized pyridine esters in this invention, significantly enhancing cucumber growth and fruit quality.

Claims

1. A compound seaweed fertilizer, characterized in that, It includes pyridine ester compounds and seaweed fertilizer, wherein the mass of the pyridine ester compounds is 1.5-2.5% of the mass of the seaweed fertilizer; the structure of the pyridine ester compounds is as follows: ； Wherein, R is a C1~C3 alkylene group; The pyridine ester compound is prepared by reacting 2-propanolpyridine with an acyl chloride compound, wherein the acyl chloride compound is 3-chloropropionyl chloride, 4-chlorobutyryl chloride, or chloroacetyl chloride, and the molar ratio of 2-propanolpyridine to the acyl chloride compound is 1:1.1~1.2; The preparation method of the seaweed fertilizer is as follows: mix and crush the algae, kelp, grapefruit peel and water to obtain a crushed liquid; then enzymatically hydrolyze the crushed liquid to obtain the seaweed fertilizer; the mass ratio of algae, kelp and grapefruit peel is 3~4:3~4:1~1.

5.

2. The compound seaweed fertilizer as described in claim 1, characterized in that, R is ethylene.

3. The compound seaweed fertilizer as described in claim 1 or 2, characterized in that, The mass ratio of the algae, kelp, grapefruit peel, and water is 3~4:3~4:1~1.5:10; the compound enzyme used in the enzymatic hydrolysis consists of protease, pectinase, oxidoreductase, and cellulase in a mass ratio of 20:8:15:35; the mass ratio of the lysate to the compound enzyme is 100:1; the pH during enzymatic hydrolysis is 6.5~7.5; the temperature is 35~40℃; and the time is 70~80h.

4. The application of a compound seaweed fertilizer as described in any one of claims 1-3.

5. The application as described in claim 4, characterized in that, The application includes the following steps: spraying the pyridine ester compounds and seaweed fertilizer in the compound seaweed fertilizer onto the plant leaves in the form of diluted solutions.

6. The application as described in claim 5, characterized in that, The plant in question is a cucumber; the spraying is carried out after the cucumber seedlings have established themselves, with a diluted seaweed fertilizer solution sprayed every 15-17 days, at a rate of 600-700 kg / hm² each time. 2 Spray cucumber seedlings with a diluted pyridine ester compound once, 18-20 days after transplanting, at a rate of 600-700 kg / hm². 2 The seaweed fertilizer dilution is prepared by mixing seaweed fertilizer and water at a mass ratio of 1~1.5g:1.5kg, and the pyridine ester compound dilution is prepared by mixing pyridine ester compound and water at a mass ratio of 0.015g:1.5kg.

7. The application as described in claim 6, characterized in that, The application is to increase cucumber yield.

8. The application as described in claim 6, characterized in that, The application is to increase the length, diameter, and flesh thickness of cucumbers.

9. The application as described in claim 6, characterized in that, The application aims to increase the content of protein, total sugar, fat, vitamin B2, vitamin C, iron, and calcium in cucumbers.

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