Application of bactericidal composition in prevention and treatment of pepper root rot

Abstract

The invention relates to the technical field of pesticides, in particular to application of a bactericidal composition to prevention and treatment of pepper root rot, the composition comprises active components and auxiliaries, the active components are propamocarb hydrochloride and fludioxonil, and the composition has an obvious synergistic effect on prevention and treatment of pepper root rot and can be used for preventing and treating pepper root rot. The main active components have different action mechanisms, can reduce the generation of drug resistance of pathogenic bacteria, is beneficial to prolonging the service life of the pesticide active components, and has the advantages of low dosage, good control effect, safety to crops and small environmental pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and particularly to the use of a bactericidal composition in controlling pepper root rot, specifically to the use of a bactericidal composition containing propamocarb hydrochloride and fludioxonil in controlling pepper root rot. Background Art

[0002] Pepper root rot is a disease caused by Fusarium solani ( Fusarium solani ), etc., which mainly harms the root and stem parts and vascular bundles of peppers, resulting in poor growth and development of plants, and even plant death in severe cases. The pathogen exists in the diseased tissues or the remains of diseased plants left in the soil in the form of mycelium and chlamydospores, and can survive in the soil for 5 to 6 years or even longer. The pathogen is transmitted through rainwater or irrigation water and invades from the wound of the plant to start the disease. The diseased part will continuously produce new conidia, causing the disease to spread over a large area. This disease is a soil-borne disease, which is distributed throughout China. The incidence rate is relatively low, but it can reach 30 - 50% in severe cases, significantly affecting the quality and yield of peppers and causing certain economic losses. Therefore, fully understanding the incidence law of pepper root rot, selecting the right time and preventing it in due time are crucial for increasing the yield of peppers.

[0003] With the rapid growth of China's pesticide production, the amount of pesticide used has increased significantly, and the phenomena of enhanced pathogen resistance and reduced pesticide efficacy have become increasingly prominent. In addition, users spray multiple times in pursuit of high pesticide efficacy and high yields, resulting in continuously increasing dosage, huge waste, environmental pollution, affecting human health, and disrupting the balance of the ecosystem. Summary of the Invention

[0004] The purpose of the present invention is to provide a bactericidal composition having a synergistic effect on pepper root rot. The active components of the bactericidal composition include propamocarb hydrochloride and fludioxonil. This composition has an obvious synergistic effect on pepper root rot. The main active components have different action mechanisms, which can reduce the generation of pathogen resistance, is conducive to extending the service life of the pesticide active components. At the same time, alkyl polyglycoside can be further added as a synergistic adjuvant. Using alkyl polyglycoside is more environmentally friendly, has the advantages of low dosage and good control effect, is safe for crops, and causes little environmental pollution.

[0005] Fludioxonil, the common English name is Fludioxonil, CAS No. 131341 - 86 - 1, molecular weight 248.18, molecular formula C 12H6F2N2O2, with the chemical name 4-(2,2-difluoro-1,3-benzodioxol-4-yl)pyrrole-3-carbonitrile. Its mechanism of action is to inhibit the protein activating enzyme PK–III (kinase PK–III) that plays a signaling role in the osmotic induction transmission process, thereby leading to an increase in the concentration of non-phosphorylated regulatory protein, and further causing abnormal secretion of the osmotic-sensitive mitogen-activated protease, ultimately resulting in the death of the pathogen. Due to its unique mechanism of action, it has no cross-resistance with existing fungicides and is a very promising class of non-systemic phenylpyrrole fungicides. Its structural formula is as follows: .

[0006] The bacteriostatic mechanism of fludioxonil is to inhibit the growth of fungal mycelium by inhibiting the transfer related to glucose phosphorylation, ultimately leading to the death of the pathogen. Its mechanism of action is unique and it has no cross-resistance with existing fungicides. It is a contact fungicide. It is used for foliar treatment of wheat, barley, corn, peas, rapeseed, rice, vegetables, grapes, lawns, and ornamental crops to control diseases caused by pathogens such as Gerlachia nivalis, Tilletia caries, and Rhizoctonia solani, and has a special effect on gray mold; it is used for seed treatment of cereals and non-cereals to control seed-borne and soil-borne pathogens, such as Alternaria, Ascochyta, Aspergillus, Gerlachia, Helminthosporium, Rhizoctonia, and Penicillium.

[0007] Propamocarb hydrochloride, with the common English name Propamocarb hydrochloride, CAS No. 25606-41-1, molecular weight 224.73, and molecular formula C9H 20 N2O2·HCl, with the chemical name N-(3-(dimethylamino)propyl)propylcarbamate hydrochloride. Propamocarb hydrochloride belongs to the carbamate fungicides and has good local systemic action. Its mechanism of action is to inhibit the synthesis of phosphoric acid and fatty acids in the cell membrane components of the pathogen, prevent its normal function, and inhibit the growth and spread of hyphae and the formation and germination of sporangia. Propamocarb hydrochloride is a broad-spectrum fungicide and has a preventive effect on diseases caused by fungi such as Pythium, Bremia, Peronospora, Phytophthora, Pseudoperonospora, and Pythium, and has a stimulating growth effect on plants. Propamocarb hydrochloride can be rapidly mineralized in water without polluting groundwater and can be photolyzed under the action of microorganisms in a short time, belonging to an environmentally friendly fungicide with ecological environmental safety. Its structural formula is as follows: .

[0008] Fludioxonil inhibits the growth of fungal mycelium, and cymoxanil hydrochloride destroys the cell membrane structure of the pathogen, preventing the growth of the pathogen's mycelium and the germination of the pathogen's spores, thus cutting off the reproduction chain of the pathogen. Fusarium solani exists in the form of mycelium and chlamydospores on diseased residues, can survive in the soil for several years, and produce new conidia for large-scale spread. The combination of the two can act on the pathogen through different pathways to prevent its growth and spread. The mixture of cymoxanil hydrochloride and fludioxonil can delay the resistance of the pathogen.

[0009] Through experiments, it was found that after the combination of fludioxonil, cymoxanil hydrochloride and alkyl polyglycoside, the dosage of fludioxonil and cymoxanil hydrochloride can be further reduced, the cost can be reduced, and the drug effect is better.

[0010] Alkyl polyglycoside (APG) is synthesized from glucose and fatty alcohol. Glycosides with more than or equal to 2 sugar units in complex glycoside compounds are collectively called alkyl polysaccharide glycosides. It has low surface tension, no cloud point, strong wetting ability, strong detergency, rich and delicate foam, strong compatibility, non-toxic, harmless, no irritation to the skin, rapid and complete biodegradation, significant thickening effect of the product, easy to dilute, no gel phenomenon, and is easy to use. As a green surfactant, alkyl polyglycoside shows significant advantages in many fields due to its unique molecular structure and the renewable nature of its synthetic raw materials: 1) Environmental protection and safety, fast biodegradation. In the natural environment (such as soil, water), alkyl polyglycoside can be quickly decomposed into CO2 and water by microorganisms, and the degradation rate is over 90%, far exceeding that of traditional chemical surfactants (such as fatty alcohol polyoxyethylene ether AEO).

[0011] 2) Low toxicity and mildness. It has extremely low irritation to human skin and is suitable for washing and care products, sensitive skin skin care products and high-end medical cleaning products; its toxicity to aquatic organisms such as fish is also significantly lower than that of benzene derivatives.

[0012] 3) No harmful residues. It does not contain harmful ingredients such as phosphorus and fluorescent agents, and complies with the EU EC1907 / 2006 regulation and the "zero burden" environmental protection concept.

[0013] 4) Multifunctional synergy, with multiple functions such as emulsification, dispersion, foaming, and thickening. It can reduce the dosage of other additives in the formula and simplify the production process. It has strong hard water resistance and can still play a stable role in the environment of high calcium and magnesium ions (hard water) without the need to compound chelating agents, reducing production costs.

[0014] Currently, the control agents on the market are carbendazim, hymexazol, microbial inoculants, etc. The mechanism of action of carbendazim is to interfere with the mitosis process of pathogenic bacteria, especially the formation of the spindle, thereby hindering cell division and ultimately leading to the death of the bacteria. Through continuous exploration and research, the inventor of this application found that the compounding of propamocarb hydrochloride and fludioxonil has a very significant synergistic effect in controlling pepper root rot. The present invention introduces two agents with different mechanisms of action to provide a new method for its control, thereby reducing the resistance of root rot bacteria to a specific agent. Using alkyl polyglycoside as a synergistic adjuvant can further improve its control effect and reduce the dosage of the bactericidal composition.

[0015] The present invention provides the use of a bactericidal composition in controlling pepper root rot. The composition includes an active ingredient and an adjuvant, and the active ingredient is propamocarb hydrochloride and fludioxonil.

[0016] The bactericidal composition containing propamocarb hydrochloride and fludioxonil provided by the present invention can reduce the dosage of pesticides, lower costs, have a more efficient bactericidal effect, be rapidly biodegradable, and cause little environmental pollution.

[0017] As a preferred embodiment, the weight ratio of propamocarb hydrochloride to fludioxonil is 1:5 - 5:1; more preferably 1 - 5:1, and even more preferably 2 - 5:1.

[0018] As a preferred embodiment, by mass, the content of the active ingredient is 1 - 50%. More preferably, the content of the active ingredient is 20 - 40%.

[0019] As a preferred embodiment, the adjuvant includes a synergistic adjuvant, and the synergistic adjuvant is alkyl polyglycoside.

[0020] Alkyl polyglycoside has good wetting and penetration properties, is insensitive to high-concentration electrolytes, is biodegradable, does not pollute crops and land, and has excellent hygroscopicity, etc. Moreover, different from traditional non-ionic surfactants, it has no inverse phase cloud point. Adding alkyl polyglycoside to the binary system of propamocarb hydrochloride and fludioxonil can effectively reduce the surface tension of the liquid medicine, delay the evaporation of the water in the liquid medicine, maintain the hydrated dissolved state of the pesticide for a long time, help improve the absorption speed and absorption rate of the pesticide by the plant leaf surface, and has a significant synergistic effect on the pesticide composition system.

[0021] As a preferred embodiment, the mass ratio of propamocarb hydrochloride to alkyl polyglycoside is 1:0.04 - 3. More preferably 1:0.1 - 1.

[0022] The present invention finds that the alkyl polyglycoside has a good effect when the weight ratio with the propamocarb hydrochloride and fludioxonil composition is within the above range, and the synergistic effect is not obvious after exceeding the above ratio range.

[0023] As a preferred embodiment, the auxiliary agent is selected from one or more of fillers, wetting agents, emulsifiers, dispersants, thickeners, antifreeze agents, defoamers, and solvents.

[0024] As a preferred embodiment, the filler is selected from one or more of bentonite, silica white, glucose, starch, diatomite, clay, kaolin, calcium carbonate, sodium chloride, potassium chloride, sodium sulfate, attapulgite, and modified attapulgite.

[0025] The solvent is selected from one or more of water, ethanol, ethylene glycol, glycerol, isopropyl alcohol, n-butanol, amyl alcohol, acetone, toluene, xylene, chlorobenzene, methanol, methyl sulfoxide, dimethylformamide, pyrrolidone, cyclohexanone, alkylene carbonate, diesel oil, solvent naphtha, vegetable oil, vegetable oil derivatives, and mineral oil.

[0026] The wetting agent is selected from one or more of dodecyl sulfate, dodecylbenzenesulfonate, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, phenolsulfonate formaldehyde condensate, polysulfonate, polyoxyethylene alkyl ether sulfate, polyvinyl alcohol, polythiol, polycarboxylate, glycerol, pyridine, Nekal, tea seed powder, soap pod powder, sapindus powder, and silkworm excrement.

[0027] The emulsifier is selected from one or more of alkylphenol formaldehyde resin polyoxyethylene ether, phenethylphenol polyoxyethylene ether, phenethylphenol polyoxypropylene ether polyoxyethylene ether, diphenylethyl biphenol polyoxyethylene ether, lauryl alcohol polyoxyethylene ether, rosin acid polyoxyethylenedithiophosphate, castor oil ethylene oxide adduct and its derivatives, triethanolamine oleate, and diglycerol fatty acid ester.

[0028] The dispersant is selected from one or more of lignin sulfonate, sodium lauryl polyoxyethylene ether sulfate, alkylnaphthalene formaldehyde condensate sulfonate, alkyl polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, sodium methylene bisnaphthalenesulfonate, polycarboxylate, alkylnaphthalene sulfonic acid condensate sodium salt, alkylphenol polyoxyethylene ether, polyacrylic acid, phosphate, and EO-PO block or graft copolymer.

[0029] The thickener is selected from one or more of ammonium chloride, lauryl alcohol, myristyl alcohol, sodium polyacrylate, coconut oil diethanolamide, cetyl alcohol polyoxyethylene ether, xanthan gum, organic bentonite, arabic gum, sodium alginate, magnesium aluminum silicate, and carboxymethyl cellulose.

[0030] The defoamer is selected from one or more of aluminum oxide, silicon oxide, silicate, sulfonate, polydimethylsiloxane, C10-C20 saturated fatty acid compounds, and C8-C10 fatty alcohols.

[0031] The antifreeze agent is selected from one or more of ethylene glycol and glycerol.

[0032] The dosage form of the bactericidal composition is one of a suspension concentrate and a wettable powder.

[0033] The compound bactericidal composition provided by the present invention can produce the following beneficial effects: 1. The pesticide synergistic composition of the present invention has an obvious synergistic effect on pepper root rot.

[0034] 2. The main active components in the pesticide synergistic composition of the present invention have different action mechanisms. When compounded and used, the generation of pathogen drug resistance can be reduced, and a synergistic effect is produced.

[0035] 3. The present invention further adds alkyl polyglycoside as a synergistic adjuvant, which can further enhance the bactericidal effects of the main bactericidal active components, propamocarb hydrochloride and fludioxonil, is beneficial to extending the service life of the pesticide active components. At the same time, the use of alkyl polyglycoside is more environmentally friendly.

[0036] 4. Propamocarb hydrochloride and fludioxonil have different action mechanisms and different action sites, and the compound shows synergism. This compound composition has no obvious synergistic effect on Colletotrichum capsici, shows an additive effect on Phytophthora infestans, and has an obvious synergistic effect on pepper root rot pathogens.

[0037] 5. The pesticide synergistic composition of the present invention has a low dosage, good control effect, and is safe for crops. Detailed implementation mode

[0038] The following further illustrates the present invention in conjunction with examples. For the experimental methods without specific conditions in the following examples, they are usually in accordance with the well-known means in the art.

[0039] For the instruments, reagents, materials, etc. involved in the following examples, unless otherwise specified, they are all conventional instruments, reagents, materials, etc. existing in the prior art and can be obtained through regular commercial channels. For the experimental methods, detection methods, etc. involved in the following examples, unless otherwise specified, they are all conventional experimental methods, detection methods, etc. existing in the prior art.

[0040] The following will detail the propamocarb hydrochloride and fludioxonil bactericidal composition, the proportional range with synergistic effect, the control object, and specific compounding examples, wherein the active ingredients are all calculated based on their active components.

[0041] Example 1 This example provides a suspension concentrate of propamocarb hydrochloride and fludioxonil (the mass fractions of propamocarb hydrochloride and fludioxonil are 5% + 25% respectively), and its weight formulation ratio is as follows: 97% propamocarb hydrochloride (active component) 5% 98% fludioxonil (active component) 25% Alkyl polyglycoside (synergistic adjuvant) 2.5% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (defoamer) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0042] The preparation method is to mix the above active components, synergistic adjuvant, dispersant, wetting agent, thickener, defoamer, antifreeze and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make the particle size D90 below 5 microns. Mix evenly and stir with a JB300-SH type stirrer at a speed of 600 rpm for 2 minutes, and filter through a filter cloth to obtain it.

[0043] Example 2 This example provides a propamocarb hydrochloride, fludioxonil suspension (the mass fractions of the two are 15% + 5% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active component) 15% 98% Fludioxonil (active component) 5% Alkyl polyglycoside (synergistic adjuvant) 3% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (defoamer) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0044] The preparation method is to mix the above active components, synergistic adjuvant, dispersant, wetting agent, thickener, defoamer, antifreeze and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make the particle size D90 below 5 microns. Mix evenly and stir with a JB300-SH type stirrer at a speed of 600 rpm for 2 minutes, and filter through a filter cloth to obtain it.

[0045] Example 3 This example provides a propamocarb hydrochloride, fludioxonil glycoside suspension (the mass fractions are 20% + 10% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active component) 20% 98% Fludioxonil (active ingredient) 10% Alkyl polyglycoside (synergistic adjuvant) 5% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) q.s. to 100%.

[0046] The preparation method is to mix the above active ingredient, synergistic adjuvant, dispersant, wetting agent, thickener, antifoaming agent, antifreeze and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make the particle size D90 below 5 microns. Mix evenly and stir with a JB300-SH type stirrer at 600 rpm for 2 minutes, and filter through a filter cloth to obtain.

[0047] Example 4 This example provides a propamocarb hydrochloride and fludioxonil suspension concentrate (mass fractions are 24% + 6% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 24% 98% Fludioxonil (active ingredient) 6% Alkyl polyglycoside (synergistic adjuvant) 8% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) q.s. to 100%.

[0048] The preparation method is to mix the above active ingredient, synergistic adjuvant, dispersant, wetting agent, thickener, antifoaming agent, antifreeze and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make the particle size D90 below 5 microns. Mix evenly and stir with a JB300-SH type stirrer at 600 rpm for 2 minutes, and filter through a filter cloth to obtain.

[0049] Example 5 This example provides a propamocarb hydrochloride and fludioxonil suspension concentrate (mass fractions of propamocarb hydrochloride and fludioxonil are 5% + 25% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 5% 98% Fludioxonil (active ingredient) 25% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0050] The preparation method is to mix the above active ingredients, dispersant, wetting agent, thickener, antifoaming agent, antifreeze with water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make the particle size D90 below 5 microns. Mix evenly and use a JB300-SH type stirrer to stir at a speed of 600 rpm for 2 minutes, and filter through a filter cloth to obtain it.

[0051] Example 6 This example provides a propamocarb hydrochloride and fludioxonil suspension (mass fractions are 20% + 10% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 20% 98% Fludioxonil (active ingredient) 10% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0052] The preparation method is to mix the above active ingredients, dispersant, wetting agent, thickener, antifoaming agent, antifreeze with water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make the particle size D90 below 5 microns. Mix evenly and use a JB300-SH type stirrer to stir at a speed of 600 rpm for 2 minutes, and filter through a filter cloth to obtain it.

[0053] Example 7 This example provides a propamocarb hydrochloride and fludioxonil suspension (mass fractions are 25% + 5% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 25% 98% Fludioxonil (active ingredient) 5% Alkyl polyglycoside (synergistic adjuvant) 4% Sodium lignosulfonate (dispersant) 4% Naphthalenesulfonic acid-formaldehyde condensate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Glycerol (antifreezing agent) 3% Xanthan gum (thickener) 0.08% Water (solvent) make up to 100%.

[0054] The preparation method is to mix the above active ingredient, synergistic adjuvant, dispersant, wetting agent, thickener, antifoaming agent, antifreezing agent and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make its particle size D90 below 5 microns. Mix evenly and use a JB300-SH type mixer to stir at 600 rpm for 2 minutes, and filter through a filter cloth to obtain.

[0055] Example 8 This example provides a propamocarb hydrochloride and fludioxonil suspension concentrate (mass fractions are 24% + 6% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 24% 98% Fludioxonil (active ingredient) 6% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreezing agent) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0056] The preparation method is to mix the above active ingredient, dispersant, wetting agent, thickener, antifoaming agent, antifreezing agent and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make its particle size D90 below 5 microns. Mix evenly and use a JB300-SH type mixer to stir at 600 rpm for 2 minutes, and filter through a filter cloth to obtain.

[0057] Example 9 This example provides a wettable powder of propamocarb hydrochloride and fludioxonil (mass fractions of propamocarb hydrochloride and fludioxonil are 14% + 2% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 14% 98% Fludioxonil (active ingredient) 2% Sodium lignosulfonate (dispersant) 5% Sodium methylenebis(naphthalenesulfonate) (dispersant) 3% Silica white (filler) 30% Sodium dodecyl sulfate (wetting agent) 1% Kaolin clay (filler) to make up 100%.

[0058] The preparation method is as follows: The active ingredient, dispersant, wetting agent, and filler are mixed in proportion by a double - helix conical mixer at a speed of 60 rpm for 2 minutes, then subjected to air - flow shearing and pulverizing by a JZDBL100 type air - flow pulverizer (3 m 3 / min) for 5 minutes, and then mixed by a stirrer (rotation speed 100 rpm) for 3 minutes to obtain the product.

[0059] Example 10 This example provides a wettable powder of propamocarb hydrochloride and fludioxonil (mass fractions are 10% + 10% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 10% 98% Fludioxonil (active ingredient) 10% Alkyl polyglycoside (synergistic adjuvant) 2% Sodium lignosulfonate (dispersant) 5% Sodium methylenebis(naphthalenesulfonate) (dispersant) 3% Silica white (filler) 30% Sodium dodecyl sulfate (wetting agent) 1% Kaolin clay (filler) to make up 100%.

[0060] The preparation method is as follows: The active ingredient, synergistic adjuvant, dispersant, wetting agent, and filler are mixed in proportion by a double - helix conical mixer at a speed of 60 rpm for 2 minutes, then subjected to air - flow shearing and pulverizing by a JZDBL100 type air - flow pulverizer (3 m 3 / min) for 5 minutes, and then mixed by a stirrer (rotation speed 100 rpm) for 3 minutes to obtain the product.

[0061] Example 11 This example provides a wettable powder of propamocarb hydrochloride and fludioxonil (mass fractions are 10% + 10% respectively), and its weight formulation ratio is as follows: 97% Propamocarb hydrochloride (active ingredient) 10% 98% Fludioxonil (active ingredient) 10% Sodium lignosulfonate (dispersant) 5% Sodium methylenebis(naphthalenesulfonate) (dispersant) 3% Silica white (filler) 30% Sodium dodecyl sulfate (wetting agent) 1% Kaolin (filler) make up to 100%.

[0062] The preparation method is as follows: The active components, dispersant, wetting agent, and filler are mixed in proportion by a double - helix conical mixer at a speed of 60 rpm for 2 minutes, then sheared and pulverized by a JZDBL100 type air - stream pulverizer (3m 3 / min) for 5 minutes, and then mixed by a stirrer (speed 100 rpm) for 3 minutes to obtain the product.

[0063] Comparative Example 1 A propamocarb hydrochloride and fludioxonil suspension (the mass fractions of propamocarb hydrochloride and fludioxonil are 5% + 30% respectively), and its weight formula ratio is as follows: 97% propamocarb hydrochloride (active component) 5% 98% fludioxonil (active component) 30% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0064] Its preparation method is to mix the above - mentioned active components, dispersant, wetting agent, thickener, antifoaming agent, antifreeze with water, then carry out high - speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make its particle size D90 less than 5 microns. After mixing evenly, use a JB300 - SH type stirrer to stir at a speed of 600 rpm for 2 minutes, and filter through a filter cloth to obtain the product.

[0065] Comparative Example 2 A propamocarb hydrochloride and fludioxonil suspension (the mass fractions of propamocarb hydrochloride and fludioxonil are 20% + 10% respectively), and its weight formula ratio is as follows: 97% propamocarb hydrochloride (active component) 20% 98% fludioxonil (active component) 10% Alkyl polyglycoside (synergistic adjuvant) 1% Sodium lignosulfonate (dispersant) 5% Polyoxyethylene alkyl ether sulfate (wetting agent) 3% Magnesium aluminum silicate (thickener) 2% Polydimethylsiloxane (antifoaming agent) 0.5% Ethylene glycol (antifreeze) 3% Xanthan gum (thickener) 0.05% Water (solvent) make up to 100%.

[0066] The preparation method is to mix the above active ingredients, synergistic adjuvants, dispersants, wetting agents, thickeners, defoamers, antifreeze agents and water, then carry out high-speed shearing (1000 rpm, 5 minutes), and then use a sand mill for sanding to make its particle size D90 below 5 microns. Mix evenly and stir with a JB300-SH type stirrer at a speed of 600 rpm for 2 minutes, and filter through a filter cloth to obtain the product.

[0067] Indoor activity determination 1.1 Experiment 1: Indoor toxicity determination test of the combination of propamocarb hydrochloride and fludioxonil against Fusarium solani f. sp. radicis-lycopersici.

[0068] 1.2 Test basis: The test refers to the Agricultural Industry Standard of the People's Republic of China NY / T 1156.2 - 2006 "Guidelines for Pesticide Bioassay in the Laboratory - Part 2: Test of Inhibiting the Mycelial Growth of Pathogenic Fungi - Petri Dish Method".

[0069] 1.3 The test materials are as follows: Test target: Fusarium solani ( Fusarium solani ), provided by the Heilongjiang Academy of Agricultural Sciences.

[0070] Instrument and equipment: High-pressure steam sterilizer, laminar flow hood, constant temperature incubator, electrothermal blast drying oven, ten-thousandth electronic balance, pipette, alcohol lamp, 50 mL beaker, volumetric flask, 100 mL conical flask, petri dish (9 cm), puncher (0.6 cm), inoculator, ruler, etc.

[0071] Cultivation conditions of the test target: Transfer the Fusarium solani preserved at 4°C indoors to PDA (Potato Dextrose Agar Medium), place it in a 25°C incubator and culture it in the dark for one week to activate it for standby.

[0072] All reagents used are general commercially available products unless otherwise specified.

[0073] 98% fludioxonil technical, provided by Shanghai Herbstar Co., Ltd.; Alkyl polyglycoside, provided by Shanghai Macklin Biochemical Co., Ltd. It should be noted that in the following experiments, the mass of alkyl polyglycoside refers to the mass of alkyl polyglycoside itself, rather than the mass of its solution; 97% propamocarb hydrochloride technical, provided by Qingdao Runong Chemical Co., Ltd. Other reagents: Acetone (analytical pure), Tween 80 (chemical pure).

[0074] 1.4 Test method Preparation of mother liquor of medicament: Dissolve 98% fluxapyroxad technical and 97% propamocarb hydrochloride technical with acetone respectively to prepare high-concentration mother liquor (10 mg / L). Then, prepare 9 groups of mixed solutions by mixing propamocarb hydrochloride and fluxapyroxad according to the mass ratios of 1:10, 1:8, 1:5, 1:2, 1:1, 2:1, 5:1, 8:1 and 10:1. Next, dilute the above single agents and mixed agents into 5 series of mass concentrations with 0.1% (mass concentration) Tween 80 aqueous solution, and on this basis, screen out the better ratio of propamocarb hydrochloride and fluxapyroxad. On the basis of preliminary tests, dilute propamocarb hydrochloride into 5 series of mass-volume concentrations of 8.1, 2.7, 0.9, 0.3, 0.1 mg / L with Tween 80 aqueous solution, dilute fluxapyroxad into 5 series of mass-volume concentrations of 0.81, 0.27, 0.09, 0.03, 0.01 mg / L, and dilute 9 groups of mixed solutions of propamocarb hydrochloride and fluxapyroxad into 6 series of mass-volume concentrations of 2.43, 0.81, 0.27, 0.09, 0.03, 0.01 mg / L (the sum concentration of propamocarb hydrochloride and fluxapyroxad).

[0075] Experiment repetition: For each concentration of the test medicament, use 4 petri dishes, with 1 petri dish for each repetition, and a total of 4 repetitions. Use 0.1% (mass concentration) Tween 80 aqueous solution without medicament as the blank control.

[0076] Medicament treatment: Under aseptic operation conditions, add 49 g of pre-melted sterilized PDA medium into a sterile conical flask. Sequentially pipette 1 mL of the medicament solution from low concentration to high concentration and add it into the above conical flask, and shake well. Then, pour an equal amount into 4 petri dishes to make drug-containing plates with corresponding concentrations.

[0077] Inoculation: For the cultured pathogenic bacteria, under aseptic conditions, use a sterilized punch with a diameter of 6 mm to cut a mycelial cake from the edge of the colony, and use an inoculator to inoculate the mycelial cake in the center of the drug-containing plate, with the mycelial surface facing up. Cover the petri dish lid and place it in an incubator at 25°C for cultivation. After 96 h of inoculation and cultivation, use a vernier caliper to measure the colony diameter in millimeters (mm). Measure the diameter of each colony vertically once with the cross method and take the average value.

[0078] According to the test investigation results, calculate the mycelial growth inhibition rate of each treatment concentration on the test target bacteria according to the following formula, with the unit of percentage (%), and retain two decimal places for the calculation results.

[0079] D = D1 - D2 In the formula: D is the colony growth diameter; D1 is the colony diameter; D2 is the mycelial cake diameter.

[0080] R = (D0 - DT) / D0 × 100% Where: R is the mycelial growth inhibition rate; D0 is the growth diameter of the colony in the blank control; DT is the growth diameter of the colony treated with the agent.

[0081] Regression analysis was performed on the logarithmic values of the concentrations of each agent and the corresponding mycelial growth inhibition rate values to calculate the EC of each agent 50 ; According to the Sun Yunpei method, the co-toxicity coefficient (CTC) of the mixture was calculated. When the co-toxicity coefficient (CTC) of the compound preparation ≥ 120, it showed a synergistic effect; when CTC ≤ 80, it showed an antagonistic effect; when 80 < CTC < 120, it showed an additive effect. The combined action type of the mixture was evaluated, and the results are shown in Table 1.

[0082] Table 1 Indoor bioassay results of the compound mixture of propamocarb hydrochloride and fludioxonil against Phytophthora capsici The test results showed that, as shown in Table 1, there were differences in the action mechanisms of propamocarb hydrochloride and fludioxonil. The combined use was beneficial to overcome or delay the development of pathogen resistance and improve the control effect. Both of them had good control effects on Phytophthora capsici. Propamocarb hydrochloride and fludioxonil showed a synergistic effect in the range of 1:5 - 5:1, and the highest activity was obtained when the mass ratio of propamocarb hydrochloride to fludioxonil was 2:1, with a co-toxicity coefficient of 194.55.

[0083] Field efficacy test Field efficacy test of the bactericidal composition of propamocarb hydrochloride, fludioxonil and alkyl polyglycoside against Phytophthora capsici

[0084] Control object: Phytophthora capsici

[0085] Test crop: Capsicum annuum (Ladi No. 1)

[0086] Test site: Dawang Village, Dianzi Town, Boxing County, Binzhou City, Shandong Province. The plot was selected as an area where Phytophthora capsici was prevalent. The soil type was brown loam, the soil fertility was medium, the irrigation facilities in the test field were good, and the cultivation conditions (soil type, water and fertilizer management, planting density and growth period) of the test plots were uniform and in line with local scientific agricultural practices (GAP).

[0087] Dosage of the agent: The tested agents and dosages are shown in Table 2 below (each ratio is by mass): Table 2 Tested agents and dosages in the examples Test method: Plot arrangement: The plot treatments of the test agents, control agents and blank control were arranged in a randomized block design, and protective rows were set around the plots; Plot area and repetition: 30m 2 , with 4 repetitions; Pesticide application method: Chili peppers are planted in the field on April 20th, with a planting density of 3000 plants per mu, a plant spacing of 35 cm, and a row spacing of 60 cm. The experiment starts on June 5th. At this time, the chili peppers are in the flowering and fruit-setting stage. Before pesticide application, the base number of root rot is investigated. A 15L knapsack electric sprayer is used to spray the stems and leaves of the chili peppers, with a water consumption of 300L / hm 2 , and the granule is applied by broadcasting.

[0088] According to the experimental investigation and the disease index investigation, based on the disease symptoms of the chili pepper roots and plants, the severity is classified as shown in Table 3 below: Table 3 Classification of the severity of chili pepper root rot and its symptom description Randomly investigate the root and plant disease conditions of 10 chili pepper plants in each plot, calculate the incidence rate and disease index of chili pepper root rot, and record the classification according to the disease severity in Table 3.

[0089] Disease index DI = ×100% Control effect = ×100%

[0090] The test results are shown in Table 4 (each ratio is by mass): Table 4 Control effect of the tested pesticides on chili pepper root rot It can be seen from the field efficacy test results in Table 4 that under the effective ingredient application rate in Table 2, the bactericidal composition prepared by the present invention has a good control effect on chili pepper root rot.

[0091] The control effects of the propamocarb hydrochloride·fludioxonil compositions in Example 2, Example 3, Example 4, Example 6, Example 7, and Example 8 on chili pepper root rot are all above 90%. Other examples also show obvious synergistic effects, showing significant advantages in control effect compared with the propamocarb hydrochloride single agent and the fludioxonil single agent. Among them, the suspension agent in Example 3 has the best control effect on chili pepper root rot, up to 94.49%; in Comparative Example 1, the ratio of propamocarb hydrochloride to fludioxonil is 1:6. At this ratio, a simple additive effect is shown, without obvious synergism. It can be seen that propamocarb hydrochloride and fludioxonil have a significant synergistic effect on controlling chili pepper root rot in the range of 1:5 - 5:1, which is of great significance for reducing pesticide dosage and increasing efficiency in controlling chili pepper root rot.

[0092] In addition, during the preparation of the control experiment, we found that when alkyl polyglycoside was used as a synergistic adjuvant, it had an obvious promoting effect on the control of pepper root rot by the combination of propamocarb hydrochloride and fludioxonil. The difference between the preparations of Example 3 and Example 6 was only that a certain amount of alkyl polyglycoside was added in Example 3, but the absolute value difference in the control efficacy between the two was 3.58%. It can be seen that alkyl polyglycoside has a significant effect on promoting the absorption or dispersion of the active ingredient on the surface of peppers. However, according to the experimental results, when the amount of alkyl polyglycoside added was too small (less than 0.1 times the weight of propamocarb hydrochloride), the synergistic effect was no longer significant.

[0093] In summary, through indoor toxicity determination and field efficacy tests, the propamocarb hydrochloride and fludioxonil of the present invention have better control efficacy within a certain proportion range than when used alone, showing good control effect on root rot, indicating the specific synergistic effect of this combination on pepper root rot. After adding alkyl polyglycoside, the control efficacy is significantly improved. The bactericidal composition or its preparation obtained by the compounding of the present invention has a significant control efficacy, and the effects are better than those of single agents. The above compounded preparation can effectively control the damage of pepper root rot, is safe for peppers without causing phytotoxicity, and has no adverse effects on other organisms. The above tests show that the obtained bactericidal composition or preparation has a bactericidal synergistic effect, with low dosage, reducing the dosage of single agents, delaying the resistance of pathogenic bacteria, and being safe for crops.

[0094] The above embodiments are only exemplary embodiments adopted to illustrate the principle of the invention. However, the present invention is not limited thereto. Those skilled in the art can make various improvements and changes without departing from the essence of the present invention, and these improvements and changes also belong to the protection scope of the present invention.

Claims

1. Use of a fungicide composition in preventing and treating pepper root rot, the composition comprising an active component and an adjuvant, wherein the active components are propamocarb hydrochloride and fludioxonil.

2. The use of the fungicidal composition as claimed in claim 1 in preventing and treating pepper root rot, characterized in that: The weight ratio of propamocarb hydrochloride to fludioxonil is 1:5-5:

1.

3. The use of the fungicidal composition as claimed in claim 1 in preventing and treating pepper root rot, characterized in that: The content of the active component is 1-50% by mass.

4. The use of the fungicidal composition as claimed in claim 1 in preventing and treating pepper root rot, characterized in that: The weight ratio of propamocarb hydrochloride to fludioxonil is 1-5:

1.

5. Use of the fungicidal composition according to any one of claims 1 to 4 in preventing and treating pepper root rot, characterized in that: The auxiliary agent includes a synergist, and the synergist is an alkyl glycoside.

6. Use of the fungicidal composition according to claim 5 in preventing and treating pepper root rot, characterized in that: The mass ratio of propamocarb hydrochloride to alkyl glycoside is 1:0.04-3.

7. Use of the fungicidal composition according to claim 5 in preventing and treating pepper root rot, characterized in that: The mass ratio of propamocarb hydrochloride to alkyl glycoside is 1:0.1-1.

8. Use of the fungicidal composition according to any one of claims 1 to 4 in preventing and treating pepper root rot, characterized in that: The auxiliary agent is selected from one or more of fillers, wetting agents, emulsifiers, dispersants, thickeners, antifreeze agents, defoamers, and solvents.

9. Use of the fungicidal composition according to claim 8 in preventing and treating pepper root rot, characterized in that: The filler is selected from one or more of bentonite, white carbon black, glucose, starch, diatomaceous earth, clay, kaolin, calcium carbonate, sodium chloride, potassium chloride, sodium sulfate, attapulgite, and modified attapulgite; The solvent is selected from one or more of water, ethanol, ethylene glycol, glycerol, isopropanol, n-butanol, amyl alcohol, acetone, toluene, xylene, chlorobenzene, methanol, methyl sulfoxide, dimethylformamide, pyrrolidone, cyclohexanone, alkylene carbonate, diesel, solvent oil, vegetable oil, vegetable oil derivatives and mineral oil; The wetting agent is selected from one or more of dodecyl sulfate, dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, phenol sulfonate formaldehyde condensate, polysulfonate, polyoxyethylene alkyl ether sulfate, polyvinyl alcohol, polythiol, polycarboxylate, glycerol, pyridine, pull open powder, tea dregs powder, saponin powder, soapberry powder, and silkworm excrement; The emulsifier is selected from one or more of alkylphenol formaldehyde resin polyoxyethylene ether, phenethylphenol polyoxyethylene ether, phenethylphenol polyoxyethylene ether polyoxypropylene ether, diphenylethyl biphenol polyoxyethylene ether, lauryl alcohol polyoxyethylene ether, rosin acid polyoxyethyl dithiophosphate, castor oil ethylene oxide adduct and its derivatives, triethanolamine oleic acid soap, diglycerol and fatty acid ester; The dispersant is selected from one or more of lignin sulfonate, sodium lauryl alcohol polyoxyethylene ether sulfate, alkyl naphthalene formaldehyde condensate sulfonate, alkyl polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, polyoxyethylene polyoxypropylene ether block copolymer, sodium methylene bisnaphthalene sulfonate, polycarboxylate, alkyl naphthalene sulfonic acid condensate sodium salt, alkylphenol polyoxyethylene ether, polyacrylic acid, phosphate, EO-PO block or graft copolymer; The thickener is selected from one or more of ammonium chloride, lauryl alcohol, myristyl alcohol, sodium polyacrylate, coconut diethanolamide, cetyl alcohol polyoxyethylene ether, xanthan gum, organic bentonite, gum arabic, sodium alginate, magnesium aluminum silicate and carboxymethyl cellulose; The defoaming agent is selected from one or more of aluminum oxide, silicon oxide, silicate, sulfonate, polydimethylsiloxane, C10-C20 saturated fatty acid compounds, and C8-C10 fatty alcohol; The antifreeze agent is selected from one or more of ethylene glycol and glycerol.

10. Use of the fungicidal composition according to any one of claims 1 to 3 in preventing and treating pepper root rot, characterized in that: The dosage form of the bactericidal composition is one of a suspension and a wettable powder.

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