Bactericidal composition for preventing and treating asparagus stem blight and preparation method thereof

Abstract

The invention relates to the technical field of agricultural biological prevention and treatment, in particular to a bactericidal composition for preventing and treating asparagus stem blight and a preparation method thereof. The composition is prepared from the following components in parts by mass: 1 to 20 parts of fluopyram, 1 to 20 parts of phenazino-1-carboxylic acid, 0.1 to 1 part of an organic silicon surfactant, 5 to 30 parts of an auxiliary agent and 29 to 92.9 parts of water. The fluopyram and the phenazino-1-carboxylic acid are compounded according to a specific proportion, and the action mechanisms of the fluopyram and the phenazino-1-carboxylic acid are complementary, so that the control effect on the asparagus stem blight is remarkably improved; meanwhile, the introduced organosilicon surfactant can reduce the surface tension of the liquid medicine, enhance the adhesion and spreading capability on the thick wax layer of asparagus and improve the utilization rate of effective components; through compounding of the biological-source phenazino-1-carboxylic acid and the chemical agent fluopyram, the problem of drug resistance enhancement caused by long-term use of a single chemical agent can be avoided, and the drug use frequency and dosage are reduced; and the introduction of biological source components reduces the risk of environmental residue, and gives consideration to both prevention and treatment effects and ecological safety.

Description

Technical Field

[0001] This invention relates to the field of agricultural biological control technology, and in particular to a bactericidal composition for controlling asparagus stem blight and its preparation method. Background Technology

[0002] Asparagus, an economic crop known as the "King of Vegetables" in the international market, is rich in amino acids, proteins, vitamins, and trace elements such as selenium and molybdenum. It is not only highly nutritious but also possesses pharmacological effects such as regulating metabolism and enhancing immunity. However, asparagus stem blight, a devastating disease caused by *Pseudomonas asparagus*, severely restricts the development of the asparagus industry. Widely distributed and highly damaging, this disease is often referred to as "asparagus cancer." In the early stages, small milky-white spots appear on the stem, which then expand into spindle-shaped or elliptical brown lesions with a sunken center and the formation of conidiophores. Ultimately, this leads to the inhibition of the stem base and leaves, causing the entire plant to die rapidly. Mild cases result in sporadic plant death and reduced yield, while severe cases can lead to complete crop failure and huge losses for growers.

[0003] Currently, the control of asparagus stem blight still relies mainly on chemical fungicides, with commonly used agents including difenoconazole and pyraclostrobin. However, the long-term use of these chemical agents alone has led to the continuous enhancement of pathogen resistance and a gradual decline in efficacy. In addition, the extensive use of chemical agents also poses environmental residue risks, affecting ecological balance and agricultural product safety. Although bio-based fungicides and some compound combinations have been attempted for control, the efficacy of single bio-based agents is unstable and difficult to cope with severe disease outbreaks; existing compound combinations generally suffer from problems such as large fluctuations in efficacy and short duration of effect, either due to insufficient component synergy or a lack of optimization for efficacy persistence. Summary of the Invention

[0004] The purpose of this invention is to address the problems of insufficient efficacy and instability in the prevention and control of asparagus stem blight in existing technologies, and to provide a fungicidal composition for the prevention and control of asparagus stem blight and its preparation method. By combining fluopyram with shenzimidic acid for synergistic effect, combining organosilicon surfactants to improve adhesion, and optimizing the preparation process to ensure stability, a highly efficient and long-lasting control of asparagus stem blight can be achieved.

[0005] To achieve the above objectives, the present invention provides a fungicide composition for preventing and controlling asparagus stem blight, comprising the following components in parts by weight: Fluopyram 1-20 parts, Shenqinmycin 1-20 parts, organosilicon surfactant 0.1-1 part, additives 5-30 parts and water 29-92.9 parts.

[0006] Preferably, the mass ratio of fluopyram to shenzimidic acid is 5:1.

[0007] Preferably, the organosilicon surfactant includes polyether-modified trisiloxane.

[0008] Preferably, the additives include at least one of dispersants, wetting agents, thickeners, and antifreeze agents.

[0009] Preferably, the dispersant includes at least one of sodium lignosulfonate and polycarboxylate.

[0010] Preferably, the wetting agent includes alkylnaphthalene sulfonate.

[0011] Preferably, the thickener includes xanthan gum.

[0012] Preferably, the antifreeze agent includes propylene glycol.

[0013] The present invention also provides a method for preparing the fungicidal composition for preventing and controlling asparagus stem blight, comprising the following steps: The components are mixed to obtain a bactericidal composition for preventing and controlling asparagus stem blight.

[0014] Preferably, after mixing the components, the process further includes adding a pH adjuster to adjust the pH value to 6.5-7.0.

[0015] The beneficial effects of this invention are as follows: 1. This invention provides a fungicidal composition for controlling asparagus stem blight, comprising the following components in parts by weight: 1-20 parts fluopyram, 1-20 parts shenqinmycin, 0.1-1 parts organosilicon surfactant, 5-30 parts adjuvant, and 29-92.9 parts water. This invention significantly enhances the control effect against asparagus stem blight by compounding fluopyram and shenqinmycin in a specific ratio. Their mechanisms of action are complementary (the former inhibits mitochondrial respiration in pathogens, while the latter induces disease resistance in plants). Simultaneously, the introduced organosilicon surfactant reduces the surface tension of the solution, enhances adhesion and spreading ability on the thick waxy layer of asparagus, and improves the utilization rate of the active ingredient. The combination of bio-derived shenqinmycin and the chemical agent fluopyram avoids the problem of increased resistance caused by long-term use of a single chemical agent, which helps extend the lifespan of the agent and reduce the frequency and dosage of application. Furthermore, the introduction of the bio-derived component reduces the amount of chemical agent used, and the active ingredient is easily degraded, reducing the risk of environmental residues and balancing control efficacy with ecological safety. Furthermore, the composition is simple and synergistically stable, enabling it to address both the prevention of mild cases and the control of the spread of severe cases.

[0016] 2. By adjusting the pH (6.5-7.0) and optimizing the preparation process, the decomposition of active ingredients is effectively avoided, and the storage stability of the formulation is improved. Detailed Implementation

[0017] This invention provides a bactericidal composition for preventing and controlling asparagus stem blight, comprising the following components in parts by weight: Fluopyram 1-20 parts, Shenqinmycin 1-20 parts, organosilicon surfactant 0.1-1 part, additives 5-30 parts and water 29-92.9 parts.

[0018] The CAS number for fluopyram is 658066-35-4.

[0019] In some embodiments of the present invention, the mass ratio of fluopyram to shenzimidic acid is 5:1.

[0020] In some embodiments of the present invention, the organosilicon surfactant includes polyether-modified trisiloxane.

[0021] The CAS number for polyether-modified trisiloxane is 27306-78-1.

[0022] In some embodiments of the present invention, the additives include at least one of dispersants, wetting agents, thickeners, and antifreeze agents.

[0023] In some embodiments of the present invention, the dispersant includes at least one of sodium lignosulfonate and polycarboxylate.

[0024] In some embodiments of the present invention, the wetting agent includes alkylnaphthalene sulfonate.

[0025] In some embodiments of the present invention, the thickener includes xanthan gum.

[0026] In some embodiments of the present invention, the antifreeze includes propylene glycol.

[0027] The present invention also provides a method for preparing the fungicidal composition for preventing and controlling asparagus stem blight, comprising the following steps: The components are mixed to obtain a bactericidal composition for preventing and controlling asparagus stem blight.

[0028] In some embodiments of the present invention, after mixing the components, the step of adding a pH adjuster to adjust the pH value to 6.5-7.0 is further included.

[0029] In some embodiments of the present invention, the preparation method of the bactericidal composition for preventing and controlling asparagus stem blight specifically includes the following steps: S1. Mix fluopyram, shenzimidic acid, dispersant, and wetting agent to obtain a first mixture; S2. Mix the first mixture with the first portion of water, and shear disperse at 1500-2500 rpm for 20-40 min. After shear dispersion, grind the mixture until the particle size D90 ≤ 5 μm to obtain the second mixture. S3. Mix the second mixture, thickener, antifreeze, silicone surfactant, and remaining water. Add a pH adjuster to adjust the pH to 6.5-7.0. Monitor the pH. If pH < 6.5, add 0.1-0.5% (w / w) triethanolamine solution to adjust the pH to 6.5-7.0. If pH > 7.0, add 0.3-1.0% (w / w) citric acid solution to adjust the pH to 6.5-7.0. No adjustment is needed if the pH is between 6.5 and 7.0. S4. After adjustment, stir for 10 minutes, retest, and repeat the steps in S3 of adding pH adjuster to adjust the pH value to 6.5-7.0 to stabilize the pH of the system at 6.5-7.0.

[0030] In some embodiments of the present invention, the mass ratio of the first portion of water to the remaining water is 6-8:2-4.

[0031] The present invention will be further described below with reference to embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0032] Example 1 This embodiment provides a bactericidal composition for preventing and controlling asparagus stem blight, comprising the following components in parts by weight: 10 parts fluopyram, 2 parts shenzimidic acid, 0.5 parts polyether-modified trisiloxane, 5 parts sodium lignosulfonate, 3 parts alkyl naphthalene sulfonate, 0.2 parts xanthan gum, 3 parts propylene glycol, and 76.3 parts water.

[0033] This embodiment also provides a method for preparing a bactericidal composition for preventing and controlling asparagus stem blight, comprising the following steps: Fluopyram, shenzimidic acid, sodium lignosulfonate, and alkylnaphthalene sulfonate were mixed to obtain a first mixture. The first mixture was then mixed with a first portion of water and sheared at 2000 rpm for 30 min. After shearing dispersion, the mixture was milled to a particle size D90 of 3.2 μm to obtain a second mixture. The second mixture, xanthan gum, propylene glycol, polyether-modified trisiloxane, and remaining water were mixed (the mass ratio of the first portion of water to the remaining water was 7:3). A pH adjuster was added to adjust the pH to 6.5-7.0. The pH value was then measured. When pH < 6.5, add 0.3% triethanolamine solution to adjust the pH to 6.5-7.0; when pH > 7.0, add 0.6% citric acid solution to adjust the pH to 6.5-7.0; when pH is between 6.5 and 7.0, no adjustment is needed; after adjustment, stir for 10 minutes, retest, and repeat the step of adding pH adjuster to adjust the pH to 6.5-7.0 until the pH of the system is stable at 6.5-7.0, thus obtaining the bactericidal composition for controlling asparagus stem blight.

[0034] Example 2 This embodiment provides a bactericidal composition for preventing and controlling asparagus stem blight, comprising the following components in parts by weight: 5 parts fluopyram, 15 parts shenzimidic acid, 0.8 parts polyether-modified trisiloxane, 8 parts sodium lignosulfonate, 3 parts alkyl naphthalene sulfonate, 0.2 parts xanthan gum, 3 parts propylene glycol, and 65 parts water.

[0035] This embodiment also provides a method for preparing a bactericidal composition for preventing and controlling asparagus stem blight, which is the same as in Example 1.

[0036] Example 3 This embodiment provides a bactericidal composition for preventing and controlling asparagus stem blight, comprising the following components in parts by weight: 1 part fluopyram, 1 part shenzimidic acid, 0.1 part polyether-modified trisiloxane, 5 parts sodium lignosulfonate, 3 parts alkyl naphthalene sulfonate, 0.2 parts xanthan gum, 3 parts propylene glycol and 86.7 parts water.

[0037] This embodiment also provides a method for preparing a bactericidal composition for preventing and controlling asparagus stem blight, which is the same as in Example 1.

[0038] Comparative Example 1 This comparative example provides a fungicidal composition for controlling asparagus stem blight, comprising the following components in parts by weight: The ingredients are: 12 parts of shenqinmycin, 0.5 parts of polyether-modified trisiloxane, 5 parts of sodium lignosulfonate, 3 parts of alkyl naphthalene sulfonate, 0.2 parts of xanthan gum, 3 parts of propylene glycol, and 76.3 parts of water.

[0039] This comparative example also provides a method for preparing a fungicidal composition for controlling asparagus stem blight, comprising the following steps: Shenqinmycin, sodium lignosulfonate, and alkylnaphthalene sulfonate were mixed to obtain a first mixture. The first mixture was then mixed with a first portion of water and sheared at 2000 rpm for 30 min. After shearing dispersion, the mixture was milled to a particle size D90 of 3.2 μm to obtain a second mixture. The second mixture, xanthan gum, propylene glycol, polyether-modified trisiloxane, and remaining water were mixed (the mass ratio of the first portion of water to the remaining water was 7:3). A pH adjuster was added to adjust the pH to 6.5-7.0. The pH was then measured. When pH < 6.5, add 0.3% triethanolamine solution to adjust the pH to 6.5-7.0; when pH > 7.0, add 0.6% citric acid solution to adjust the pH to 6.5-7.0; when pH is between 6.5 and 7.0, no adjustment is needed; after adjustment, stir for 10 minutes, retest, and repeat the step of adding pH adjuster to adjust the pH to 6.5-7.0 until the pH of the system is stable at 6.5-7.0, thus obtaining the bactericidal composition for controlling asparagus stem blight.

[0040] Comparative Example 2 This comparative example provides a fungicidal composition for controlling asparagus stem blight, comprising the following components in parts by weight: The mixture contains 12 parts fluopyram, 0.5 parts polyether-modified trisiloxane, 5 parts sodium lignosulfonate, 3 parts alkyl naphthalene sulfonate, 0.2 parts xanthan gum, 3 parts propylene glycol, and 76.3 parts water.

[0041] This comparative example also provides a method for preparing a fungicidal composition for controlling asparagus stem blight, comprising the following steps: Fluopyram, sodium lignosulfonate, and alkylnaphthalene sulfonate were mixed to obtain a first mixture. The first mixture was then mixed with a first portion of water and sheared at 2000 rpm for 30 min. After shearing dispersion, the mixture was milled to a particle size D90 of 3.2 μm to obtain a second mixture. The second mixture, xanthan gum, propylene glycol, polyether-modified trisiloxane, and remaining water were mixed (the mass ratio of the first portion of water to the remaining water was 7:3). A pH adjuster was added to adjust the pH to 6.5-7.0. The pH was then measured. When pH < 6.5, add 0.3% triethanolamine solution to adjust the pH to 6.5-7.0; when pH > 7.0, add 0.6% citric acid solution to adjust the pH to 6.5-7.0; when pH is between 6.5 and 7.0, no adjustment is needed; after adjustment, stir for 10 minutes, retest, and repeat the step of adding pH adjuster to adjust the pH to 6.5-7.0 until the pH of the system is stable at 6.5-7.0, thus obtaining the bactericidal composition for controlling asparagus stem blight.

[0042] Comparative Example 3 This comparative example provides a fungicidal composition for controlling asparagus stem blight, comprising the following components in parts by weight: 10 parts fluopyram, 2 parts shenzimidic acid, 5 parts sodium lignosulfonate, 3 parts alkyl naphthalene sulfonate, 0.2 parts xanthan gum, 3 parts propylene glycol, and 76.8 parts water.

[0043] This embodiment also provides a method for preparing a bactericidal composition for preventing and controlling asparagus stem blight, comprising the following steps: Fluopyram, shenzimidic acid, sodium lignosulfonate, and alkylnaphthalene sulfonate were mixed to obtain a first mixture. The first mixture was then mixed with a first portion of water and sheared at 2000 rpm for 30 min. After shearing dispersion, the mixture was milled to a particle size D90 of 3.2 μm to obtain a second mixture. The second mixture, xanthan gum, propylene glycol, and remaining water were mixed (the mass ratio of the first portion of water to the remaining water was 7:3). A pH adjuster was added to adjust the pH to 6.5-7.0. The pH was then measured. When the pH < 0.0, the pH was adjusted accordingly. At pH 6.5, add 0.3% triethanolamine solution to adjust the pH to 6.5-7.0; when pH > 7.0, add 0.6% citric acid solution to adjust the pH to 6.5-7.0; when pH is between 6.5 and 7.0, no adjustment is needed; after adjustment, stir for 10 minutes, retest, and repeat the step of adding pH adjuster to adjust the pH to 6.5-7.0 until the pH of the system is stable at 6.5-7.0, thus obtaining the bactericidal composition for controlling asparagus stem blight.

[0044] Experimental Example 1 The efficacy of the fungicidal compositions for controlling asparagus stem blight in Examples 1-3 and Comparative Examples 1-3 was tested at an asparagus base in Weifang (soil type: sandy loam, pH: 6.8, organic matter content: 1.2%; asparagus variety: UC157, stem lesion rate: 15% before first application, disease index: 56.1). Each fungicide composition was tested three times (average result was taken), and the area of ​​each test area was 20 m². 2(5m×4m), with a 1m isolation row in each test area to avoid cross-contamination of the agents. Each fungicide composition was diluted 1000 times and sprayed at the initial stage of disease, with a 7-day interval, for 3 consecutive applications. Disease index was investigated and efficacy calculated 10, 20, and 30 days after the last application. 20 plants were randomly sampled from each test area, and the number of diseased plants at each level was recorded. The disease index was calculated as "Disease Index = Σ(Number of diseased plants at each level × Corresponding level) / (Total number of plants × Highest level) × 100". Efficacy (%) was calculated as "(Disease index of blank control area - Disease index of treatment area) / ... The control efficacy was calculated by multiplying the disease index of the blank control area by 100. Disease severity was graded according to NY / T1464.24-2007: Grade 0: No lesions; Grade 1: ≤3 lesions per plant, maximum lesion diameter ≤5mm; Grade 2: 4-6 lesions per plant, or maximum lesion diameter 6-10mm; Grade 3: 7-10 lesions per plant, or maximum lesion diameter 11-20mm, or lesion circumference ≤1 / 3 of the stem; Grade 4: >10 lesions per plant, or maximum lesion diameter >20mm, or lesion circumference >1 / 3 of the stem, or plant death. The test results are recorded in Table 1.

[0045] Table 1 Test Results As can be seen from Table 1, the duration of efficacy of Examples 1-3 was significantly better than that of the comparative examples: 30 days after the last application, the efficacy of Example 1 was still 82.0%, while the efficacy of Comparative Examples 1-3 was less than 60%. This indicates that the synergistic effect of fluopyram and shenqinmycin, as well as the adhesion-enhancing effect of the organosilicon surfactant, jointly extended the duration of efficacy.

[0046] Therefore, the present invention employs the above-mentioned fungicidal composition and preparation method for controlling asparagus stem blight. By compounding fluopyram and shenqinmycin in a specific ratio, their mechanisms of action are complementary (the former inhibits mitochondrial respiration of pathogens, while the latter induces disease resistance in plants), thereby significantly improving the control effect on asparagus stem blight. At the same time, the introduced organosilicon surfactant can reduce the surface tension of the liquid, enhance its adhesion and spreading ability on the thick waxy layer of asparagus, and improve the utilization rate of the active ingredients.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bactericidal composition for controlling asparagus stem blight, characterized in that, The components include the following parts by mass: Fluopyram 1-20 parts, Shenqinmycin 1-20 parts, organosilicon surfactant 0.1-1 part, additives 5-30 parts and water 29-92.9 parts.

2. The bactericidal composition for controlling asparagus stem blight according to claim 1, characterized in that, The mass ratio of fluopyram to shenzimidic acid is 5:

1.

3. The bactericidal composition for controlling asparagus stem blight according to claim 1 or 2, characterized in that, Organosilicon surfactants include polyether-modified trisiloxanes.

4. The bactericidal composition for controlling asparagus stem blight according to claim 1 or 2, characterized in that, Additives include at least one of dispersants, wetting agents, thickeners, and antifreeze agents.

5. The bactericidal composition for controlling asparagus stem blight according to claim 4, characterized in that, The dispersant includes at least one of sodium lignosulfonate and polycarboxylate.

6. The bactericidal composition for controlling asparagus stem blight according to claim 4, characterized in that, Wetting agents include alkyl naphthalene sulfonates.

7. The bactericidal composition for controlling asparagus stem blight according to claim 4, characterized in that, Thickeners include xanthan gum.

8. The bactericidal composition for controlling asparagus stem blight according to claim 4, characterized in that, Antifreeze agents include propylene glycol.

9. A method for preparing the bactericidal composition for controlling asparagus stem blight according to any one of claims 1-8, characterized in that, Includes the following steps: The components are mixed to obtain a bactericidal composition for preventing and controlling asparagus stem blight.

10. The method for preparing the bactericidal composition for controlling asparagus stem blight according to claim 9, characterized in that, The process of mixing the components also includes adding a pH adjuster to adjust the pH value to 6.5-7.0.

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