A preparation for preventing rubber tree diseases and a method for preparing the same

Abstract

This invention discloses a formulation for preventing rubber tree diseases and its preparation method. The formulation comprises the following components in parts by weight: 10-15 parts chitosan, 1-2 parts citric acid, 3-5 parts mixed oil, 6-8 parts sodium nitrophenolate, 2-3 parts triadimefon, 3-5 parts sodium dodecyl sulfate, and 5-6 parts reinforcing agent. The mixed oil comprises glycerol and paraffin oil, and the reinforcing agent comprises calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate. The prepared coating agent forms a waterproof membrane on the rubber tree's tapped surface, reducing stripe canker disease, increasing growth nutrients on the tapped surface, promoting rapid growth of regenerated bark, and providing frost protection.

Description

Technical Field

[0001] This invention relates to the technical field of agricultural and forestry protection, and in particular to a preparation for preventing diseases of rubber trees and its preparation method. Background Technology

[0002] The characteristics of cold waves in Hainan are low temperatures, little sunshine, and prolonged periods of overcast and rainy weather. This prolonged period of low temperatures and overcast skies causes numerous wounds on the trunks of rubber trees, making them susceptible to tap-surface canker. This manifests as striped or patchy lesions on the tapped surface, with necrosis of the surface layer, accompanied by latex exudation or the oozing of a yellowish-brown liquid. Under low humidity conditions, a white mold layer grows on the affected area. On older tapped surfaces or the original bark, the bark bulges, cracks, and oozes latex. Removing the outer bark reveals dark brown lesions, primarily caused by various fungi, including *Phytophthora brownii*. After being damaged by the cold, the necrosis of the bark hinders latex production after tapping, preventing the rubber trees from producing latex. The most basic preventative measure against cold damage is protecting the tapped surface, preventing cold air and rainwater from directly penetrating it, effectively preventing tap-surface diseases in rubber trees.

[0003] Traditional protective techniques involve coating the cut surface with petroleum jelly and asphalt, which offers poor antifreeze effects and requires repeated coating, making it extremely inconvenient. Chitosan is a natural polymer material with excellent film-forming properties, but its application as a protective agent for rubber tree cut surfaces has received little research. Furthermore, chitosan development has long focused on acetic acid dissolution systems. In acetic acid systems, the dissolved mass fraction of chitosan is relatively low, and excessively high solubility makes the chitosan solution very viscous, preventing the dissolution of more chitosan and hindering the utilization of many of its excellent properties. Therefore, it is necessary to research and improve the solubility of chitosan and apply it to techniques such as frost protection for rubber tree cut surfaces, which is of great significance for the ecological protection of rubber trees. Summary of the Invention

[0004] In view of this, the present invention provides a formulation for preventing rubber tree diseases and a method for preparing the same. The formulation is used to apply a sealing film to the trunk and cut wounds of rubber trees to reduce damage from cold damage, reduce fungal infection damage, and reduce stripe canker.

[0005] The technical means adopted in this invention are as follows: a preparation for preventing diseases of rubber trees, the preparation comprising the following components in parts by weight: 10-15 parts chitosan, 1-2 parts citric acid, 3-5 parts mixed oil, 6-8 parts sodium nitrophenolate, 2-3 parts triadimefon, 3-5 parts sodium dodecyl sulfate, and 5-6 parts reinforcing agent; the mixed oil comprises the following components: glycerol and paraffin oil, and the reinforcing agent comprises the following components: calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate.

[0006] Furthermore, the mass ratio of calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin and potassium persulfate is 4-6:1-2:3-5:2-4:1-3.

[0007] Furthermore, the mass ratio of glycerin to paraffin oil is 3 to 4:2.

[0008] Furthermore, the formulation comprises the following components in parts by weight: 13 parts chitosan, 1 part citric acid, 4 parts mixed oil, 7 parts sodium nitrophenolate, 2 parts triazolone, 4 parts sodium dodecyl sulfate, and 6 parts reinforcing agent.

[0009] This invention also provides a method for preparing an agent to prevent rubber tree diseases, comprising the following steps:

[0010] S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use.

[0011] S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir until well mixed.

[0012] S3. Dissolve calcium chloride in water and add it to the emulsion in step S2. Mix well and let stand at a constant temperature.

[0013] S4. Add the dissolved gelatin and glutaraldehyde to another part of the chitosan solution and mix well. Finally, add the remaining components and homogenize and emulsify to obtain the coating agent.

[0014] Furthermore, in step S3, the emulsion is allowed to stand at a constant temperature of 40–45°C for 10–20 minutes.

[0015] Furthermore, in step S2, the stirring and mixing rate is 800–1000 r / min, and the stirring time is 15–20 min.

[0016] Furthermore, in step S4, the homogenization rate is 15000–20000 r / min, the homogenization temperature is 40–50℃, and the homogenization time is 45–60 min.

[0017] The beneficial effects of this invention are as follows: The formulation for preventing rubber tree diseases provided by this invention forms a water-impermeable membrane after being coated onto the rubber tree's tapping surface, reducing stripe canker disease, increasing growth nutrients to the tapping surface, promoting rapid growth of regenerated bark, and providing frost and cold protection. Chitosan molecules contain a large number of hydrophilic and hydrophobic groups. In acidic systems such as citric acid and dilute acetic acid, chitosan dissolves. Different acids dissolve chitosan, increasing the viscosity of the film and protonating the amino groups. Chitosan is also water-soluble, becoming an amphoteric molecule that can adsorb at the oil-water interface, helping to improve emulsification activity. The intermolecular forces between the mixed oil and sodium dodecyl sulfate at the dispersion interface are enhanced, increasing the film strength. Sodium nitrophenolate and triadimefon have a promoting effect on the rubber tree tapping surface. Because chitosan contains a large number of hydrophilic groups, to prevent material loss and decreased stability due to swelling in acidic solutions, reinforcing agents are used to improve the film-forming properties of the emulsion. The coordination of calcium ions with chitosan and hydroxyl groups in water enhances the emulsion's antifreeze properties and tensile strength. The addition of calcium chloride improves the emulsion's tensile properties, giving it high strength and antifreeze properties. The preparation method involves preparing the components into a coating agent with good mechanical properties. After the emulsion is compounded with calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate in a certain mass ratio, the chitosan film-forming material dissolves to form a three-dimensional network structure, improving adhesion. When coated on a cut surface, it will not disintegrate, increasing the film's tensile strength, decreasing water permeability, and enhancing structural stability. Detailed Implementation

[0018] The principles and features of the present invention are described below. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0019] Example 1

[0020] A formulation for preventing diseases of rubber trees, the formulation comprising the following components in the following mass ratios: 10 parts chitosan, 1 part citric acid, 3 parts mixed oil, 6 parts sodium nitrophenolate, 2 parts triadimefon, 3 parts sodium dodecyl sulfate, and 5 parts reinforcing agent; the mixed oil comprising glycerol and paraffin oil in a mass ratio of 3:2, and the reinforcing agent comprising calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate in a mass ratio of 5:1:3:2:1.

[0021] The preparation method of the formulation includes the following steps:

[0022] S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use.

[0023] S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir at a mixing rate of 800 r / min for 15 min.

[0024] S3. Dissolve calcium chloride in water and add it to the emulsion in step S2. Mix well and let stand at a constant temperature of 40°C for 10 minutes.

[0025] S4. Add the dissolved gelatin and glutaraldehyde to another part of the chitosan solution and mix well. Finally, add the remaining components and homogenize and emulsify. The homogenization rate is 15000 r / min, the homogenization temperature is 40℃, and the homogenization time is 45 min to obtain the coating agent.

[0026] Example 2

[0027] A formulation for preventing diseases of rubber trees, the formulation comprising the following components in the following mass ratios: 15 parts chitosan, 2 parts citric acid, 5 parts mixed oil, 8 parts sodium nitrophenolate, 3 parts triadimefon, 5 parts sodium dodecyl sulfate, and 6 parts reinforcing agent; the mixed oil comprising glycerol and paraffin oil in a mass ratio of 4:2, and the reinforcing agent comprising calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate in a mass ratio of 10:2:6:4:3.

[0028] The preparation method of the formulation includes the following steps:

[0029] S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use.

[0030] S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir at a rate of 1000 r / min for 20 min.

[0031] S3. Dissolve calcium chloride in water and add it to the emulsion in step S2. Mix well and let stand at a constant temperature of 45°C for 20 minutes.

[0032] S4. Add the dissolved gelatin and glutaraldehyde to another part of the chitosan solution and mix well. Finally, add the remaining components and homogenize and emulsify. The homogenization rate is 20000 r / min, the homogenization temperature is 50℃, and the homogenization time is 60 min to obtain the coating agent.

[0033] Example 3

[0034] A formulation for preventing diseases of rubber trees, the formulation comprising the following components in the following mass ratios: 13 parts chitosan, 1 part citric acid, 4 parts mixed oil, 7 parts sodium nitrophenolate, 2 parts triadimefon, 4 parts sodium dodecyl sulfate, and 6 parts reinforcing agent; the mixed oil comprising glycerol and paraffin oil in a mass ratio of 4:2, and the reinforcing agent comprising calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate in a mass ratio of 8:2:5:3:2.

[0035] The preparation method of the formulation includes the following steps:

[0036] S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use.

[0037] S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir at a mixing rate of 900 r / min for 18 min.

[0038] S3. Dissolve calcium chloride in water and add it to the emulsion in step S2. Mix well and let stand at a constant temperature of 42°C for 20 minutes.

[0039] S4. Add the dissolved gelatin and glutaraldehyde to another part of the chitosan solution and mix well. Finally, add the remaining components and homogenize and emulsify. The homogenization rate is 18000 r / min, the homogenization temperature is 45℃, and the homogenization time is 50 min to obtain the coating agent.

[0040] Effect test

[0041] Comparative Example 1: The difference between this comparative example and Example 3 is that the formulation comprises the following components in the following mass ratio: 15 parts chitosan, 1 part citric acid, 4 parts mixed oil, 7 parts sodium nitrophenolate, 2 parts triazolone, and 5 parts sodium dodecyl sulfate; the mixed oil comprises glycerol and paraffin oil in the following mass ratio of 4:2.

[0042] Comparative Example 2: The difference between this comparative example and Example 3 is that the reinforcing agent includes calcium chloride, gelatin, and glutaraldehyde in a mass ratio of 8:5:5.

[0043] Comparative Example 3: The difference between this comparative example and Example 3 is that the reinforcing agent comprises calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin and potassium persulfate in the following mass ratio of 8:3:2:3:2.

[0044] Comparative Example 4: The difference between this comparative example and Example 3 is that the preparation method of the formulation includes the following steps:

[0045] S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use.

[0046] S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir at a mixing rate of 900 r / min for 18 min.

[0047] S3. Add calcium chloride, gelatin, and glutaraldehyde to another portion of the chitosan solution and mix well. Finally, add the remaining components and homogenize and emulsify. The homogenization rate is 18000 r / min, the homogenization temperature is 45℃, and the homogenization time is 50 min to obtain the coating agent.

[0048] Comparative Example 5: The difference between this comparative example and Example 3 is that the preparation method of the formulation includes the following steps:

[0049] S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use.

[0050] S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir at a rate of 1200 r / min for 25 min.

[0051] S3. Dissolve calcium chloride in water and add it to the emulsion in step S2 and mix well.

[0052] S4. Homogenize and emulsify the remaining components and another part of the chitosan solution at a low speed of 5000 r / min, a homogenization temperature of 30℃, and a homogenization time of 60 min to obtain the coating agent.

[0053] 1. Mechanical property analysis of coating agents

[0054] Measure 15 ml of the coating emulsion prepared in the above examples and comparative examples, apply it evenly to a 10 cm × 10 cm glass plate, allow it to dry naturally, observe it every 10 minutes and record the drying time. After drying, soak it in sodium hydroxide solution for 35 minutes, rinse it, peel off the film and let it air dry for later use. The thickness was measured using a 001-X type spiral micrometer; the tensile strength and elongation at break of the film were determined according to national standard GB / 4456284; the water resistance grade of the cut-face coating film was determined according to national standard GB / T 1733-1993, the method for determining the water resistance of paint films. Five films were taken from each group of samples, and the average value was recorded in Table 1 below:

[0055]

[0056] Compared to the comparative example, the coating agent in the examples has a shorter film-forming time and increased tensile strength and elongation at break. The coating agent of the present invention is beneficial for increasing the mechanical properties of the coating. The coating agent prepared by the proportions of the components exhibits good adhesion to the rubber tree cut surface, waterproofing, cold protection, and non-disintegration on the cut surface. The film-forming properties of the chitosan emulsion are enhanced by the reinforcing agent, achieving antifreeze properties and tensile strength. The addition of the reinforcing agent improves the tensile properties of the emulsion, giving it high-strength antifreeze properties. Compared to Comparative Example 1 without the reinforcing agent, its mechanical properties are inferior to those of the examples. The emulsion of the present invention, after being compounded with calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate, forms a larger three-dimensional network structure, improving adhesion and preventing disintegration when coated on the cut surface. The tensile strength of the film increases, water permeability decreases, and structural stability is enhanced.

[0057] 2. Study on the antibacterial effect of coating agent on Phytophthora brown rot on the cut surface of citrus.

[0058] The antibacterial effect of the coating agent on the cut surface was determined according to the national standard QB / T2591-2003 using the plate colony counting method. The inoculated fungus was *Phytophthora brown rot*. The suspension of *Phytophthora brown rot* spores was diluted to 10... 6 CFU / mL was used as the bacterial suspension for the test. The cross-section coating agents from the examples and comparative examples were applied to the culture medium and placed in an incubator. After drying and film formation, the bacterial suspension was inoculated. The inoculation volume was 0.2 mL of diluted bacterial suspension. After incubation at 36°C for 45 h, the colony count was compared with that of the blank control plate. The antibacterial rate was calculated using the dilution separation plate colony counting method: Antibacterial rate % = (N0 - N1) / N0 × 100%. Where: N0 is the colony count under blank conditions, and N1 is the colony count of the test sample. The antibacterial rate data are recorded in Table 2 below:

[0059] Example 1 99.80 Example 2 99.85 Example 3 99.93 Comparative Example 1 96.17 Comparative Example 2 96.43 Comparative Example 3 97.82 Comparative Example 4 98.85 Comparative Example 5 99.62

[0060] As shown in the table above, the cutting surface coating agent of this embodiment has a significant antibacterial ability against Phytophthora brown rot of citrus, reaching up to 99.93%. Its antibacterial rate is higher than that of the comparative example. The active ingredients added in this embodiment isolate the coating agent from cold air, reduce the disease of cutting surface ulcers, and greatly improve the antibacterial effect.

[0061] 3. Study on the cold-proof effect of coating agent on rubber tree tap surface sealing

[0062] Rubber trees of the same variety and under the same conditions were selected as experimental subjects to study the bark breakage and latex exudation on the tapped surface. Twenty newly tapped rubber trees were coated with a tapping surface sealant on the tapping line and the freshly tapped surface. Another 20 trees were coated with Vaseline, and 20 trees served as a blank control group. After the tapped surfaces were coated with the sealant from the examples and comparative studies, observations and treatments were conducted during winter. The extent of bark breakage and latex exudation on the tapped surface was then recorded after winter. Grade 1 breakage was defined as the breakage area not exceeding 1 / 2 of the tapped surface; Grade 2 breakage was defined as the breakage area exceeding 1 / 2 but not exceeding the tapped surface; and Grade 3 breakage was defined as the breakage area exceeding the tapped surface. The effects of different sealant coatings on the bark breakage of rubber trees are recorded in Table 3 below.

[0063]

[0064] In the example, the number of rubber trees treated with the coating agent without bark peeling was up to 20. The coating agent formed by the compounding of various components of this invention has good film-forming and water-resistant properties. It can form a protective film on the rubber tree's cut surface, which is cold-proof and antibacterial. It effectively blocks external conditions from damaging the cut surface and is not easily washed away by rainwater. It can protect the rubber tree's cut surface to safely overwinter and inhibit or kill pathogenic fungi, preventing the rubber tree's cut surface from being infected with diseases such as stripe canker.

[0065] In summary, this invention provides a formulation for preventing rubber tree diseases and its preparation method. When the formulation is applied to the cut surface of the rubber tree, it forms a waterproof membrane, reducing stripe canker disease, increasing growth nutrients to the cut surface, promoting rapid regeneration of the bark, and providing frost and cold protection. The film-forming properties of the emulsion are enhanced by a reinforcing agent. The coordination of calcium ions with protonated amino groups and hydroxyl groups in water improves the emulsion's freeze resistance and tensile strength. The addition of calcium chloride improves the emulsion's tensile properties, giving it high-strength freeze resistance. When the emulsion is compounded with calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate, chitosan forms a three-dimensional network structure, increasing adhesion and preventing disintegration when coated on the cut surface. This increases the film's tensile strength, reduces water permeability, and enhances structural stability.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A preparation for preventing diseases of rubber trees, characterized in that, The formulation comprises the following components in parts by weight: 10-15 parts chitosan, 1-2 parts citric acid, 3-5 parts mixed oil, 6-8 parts sodium nitrophenolate, 2-3 parts triadimefon, 3-5 parts sodium dodecyl sulfate, and 5-6 parts reinforcing agent; the mixed oil is glycerol and paraffin oil in a mass ratio of 3-4:2, and the reinforcing agent is calcium chloride, gelatin, glutaraldehyde, β-cyclodextrin, and potassium persulfate in a mass ratio of 4-6:1-2:3-5:2-4:1-3. The preparation method of the formulation includes the following steps: S1. Chitosan is dissolved in dilute acetic acid to prepare a chitosan solution, which is then divided into two parts for later use. S2. Add the mixed oil, citric acid and sodium dodecyl sulfate to a portion of the chitosan solution from step S1 and stir until well mixed. The stirring speed is 800~1000 r / min and the stirring time is 15~20 min. S3. Dissolve calcium chloride in water and add it to the emulsion in step S2. Mix well and let stand at a constant temperature of 40-45℃ for 10-20 minutes. S4. Add the dissolved gelatin and glutaraldehyde to another part of the chitosan solution and mix well. Finally, add the remaining components and homogenize and emulsify. The homogenization rate is 15000~20000 r / min, the homogenization temperature is 40~50℃, and the homogenization time is 45~60 min to obtain the coating agent.

2. The preparation for preventing rubber tree diseases according to claim 1, characterized in that, The formulation comprises the following components in parts by weight: 13 parts chitosan, 1 part citric acid, 4 parts mixed oil, 7 parts sodium nitrophenolate, 2 parts triazolone, 4 parts sodium dodecyl sulfate, and 6 parts reinforcing agent.

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