Application of bactericidal composition for preventing and treating wheat rust

Abstract

The invention relates to application of a bactericidal composition to prevention and treatment of wheat rust, in particular to the bactericidal composition which comprises effective active ingredients of pyraclostrobin and cyproconazole, and is mainly characterized in that the weight ratio of pyraclostrobin to cyproconazole is 5: 1-1: 1, the composition is prepared into water dispersible granules, and the dosage of the effective active ingredients is 3-50g / hectare.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticides, and particularly relates to the use of a bactericidal composition for controlling wheat rust. The bactericidal composition is composed of pyraclostrobin, cyproconazole, a synergist, and an adjuvant. Background Art

[0002] Pyraclostrobin, with the chemical name of methyl N-[2-[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxymethyl]phenyl]-N-methoxycarbamate, has the chemical formula of C 19 H 18 ClN3O4. Pyraclostrobin is a strobilurin fungicide that inhibits mitochondrial respiration and ultimately leads to cell death, and has protective, therapeutic, and leaf penetration and conduction effects. It is mainly used to control various diseases caused by fungi on crops. Pyraclostrobin has good control effects on wheat powdery mildew and scab. In addition to its direct effect on pathogenic bacteria, pyraclostrobin can also induce physiological phenomena in many crops, especially cereals, such as increasing nitrogen absorption, thereby promoting the rapid growth of crops and increasing crop yields, so as to achieve the purpose of high crop yields.

[0003] Cyproconazole belongs to triazole fungicides. It is a sterol demethylation inhibitor and has preventive and therapeutic effects. It is effective against powdery mildew, rust, sphaerotheca, rhynchosporium, septoria, and venturia on cereal crops, coffee, sugar beet, fruit trees, and grapes. When mixed with other fungicides, it can effectively control eyespot, leaf spot, and net blotch of cereals. The effective duration for controlling wheat rust is 4 - 6 weeks, and for controlling powdery mildew is 3 - 4 weeks. It can control powdery mildew of cereals, fruit trees, and grapes, leaf spot of peanuts and sugar beet, apple scab, and peanut white rot.

[0004] Wheat rust, also known as jaundice, mainly includes stem rust, leaf rust, and stripe rust, which are diseases that occur on wheat caused by stem rust pathogen, leaf rust pathogen, and stripe rust pathogen respectively. It mainly damages wheat leaves, and can also damage leaf sheaths, stems, and ears. After wheat is infected, the grains are not plump in mild cases, and the wheat plants die and cannot head in severe cases.

[0005] The main characteristics of wheat rust are strong harmfulness and wide influence range. Once infected, it will have a serious impact on wheat growth and then reduce wheat yields. Wheat rust belongs to fungal diseases. The most frequently occurring wheat rusts currently are stem rust, leaf rust, and stripe rust. Among them, leaf rust has the highest occurrence range, incidence rate, and harmfulness among the three diseases. Generally, the yield reduction is 5 - 15%, and in severe cases, it can reach 50%.

[0006] The above inventors found through experiments that by preparing a water-dispersible granule composition from pyraclostrobin and cyproconazole with different action mechanisms in a certain proportion, the occurrence of wheat rust can be effectively prevented, the control cost can be reduced, and it is highly safe for crops. Summary of the Invention

[0007] The object of the present invention is to provide a use of a bactericidal composition for controlling wheat rust.

[0008] The technical solution of the present invention is as follows:

[0009] A use of a bactericidal composition for controlling wheat rust, wherein the effective active ingredients of the bactericidal composition are pyraclostrobin and cyproconazole, and the weight ratio of pyraclostrobin to cyproconazole is 5:1 to 1:1, preferably the weight ratio is 3:1 to 1:1, and the optimal weight ratio is 5:3;

[0010] Furthermore, the bactericidal composition contains pyraclostrobin, cyproconazole, synergist and silica white mixture, and adjuvant, and is made into a water dispersible granule;

[0011] Furthermore, the total weight of pyraclostrobin and cyproconazole in the bactericidal composition is 20% - 77%, preferably the total weight is 70%;

[0012] Furthermore, the dosage of the active ingredient of the bactericidal composition is 3 - 50 g / hectare.

[0013] Furthermore, the synergist is a mixture of polyethoxylated modified silane and polyethoxylated modified fatty alcohol or alkoxy modified polysiloxane.

[0014] Furthermore, the adjuvant is selected from one or more of a dispersant, a wetting agent, a binder, an antifoaming agent, a pH regulator, and a filler.

[0015] The dispersant is selected from one or more of alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, alkylphenol polyoxyethylene ether formaldehyde condensate phosphate, sodium methylene bisnaphthalene sulfonate, sodium or calcium lignosulfonate, melamine formaldehyde resin, alkylnaphthalene sulfonate, EO-PO block polyether, styrene phenol polyoxyethylene ether phosphate, alkylnaphthalene formaldehyde condensate sulfonate, alkylphenol polyoxyethylene ether phosphate ester, alkylphenol polyoxyethylene ether sulfonate, phenethylphenol polyoxyethylene ether phosphate ester, alkyl polyoxyethylene ether sulfonate, polyoxyethylene polyoxypropylene block copolymer, dodecyl polyoxyethylene ether phosphate ester, fatty alcohol polyoxyethylene ether phosphate ester, nonylphenol polyoxyethylene ether phosphate ester, sodium naphthalene sulfonate formaldehyde condensate block copolymer, comb-shaped polycarboxylate, and sodium polycarboxylate;

[0016] The wetting agent(s) selected from one or more of sodium dodecylbenzenesulfonate, sodium diisobutylnaphthalenesulfonate, sorbitan fatty acid ester, sodium sulfosuccinate dioctyl ester, alkylsulfosuccinate, phenethylphenol polyoxyethylene ether phosphate, alkyl sulfate, alkyl sulfonate, alkylnaphthalene sulfonate, alkylphenol formaldehyde resin polyoxyethylene ether, tribenzylethylphenol polyoxypropylene polyoxyethylene block polymer, sodium dodecyl sulfate, styrylphenol formaldehyde resin propylene oxide block polyether, castor oil polyoxyethylene ether, fatty alcohol polyoxyethylene ether, alkyl glycoside, sodium fatty alcohol polyoxyethylene ether sulfonate;

[0017] The binder(s) selected from one or more of water, starch, polyvinylpyrrolidone, polyethylene glycol, glucose, polyvinyl alcohol;

[0018] The pH regulator(s) selected from one or more of glacial acetic acid, citric acid, light calcium carbonate, potassium dihydrogen phosphate, triethanolamine;

[0019] The defoamer(s) selected from one or more of silicone, fatty alcohol, fatty acid;

[0020] The filler(s) selected from one or more of silica white, calcined kaolin, ammonium sulfate, potassium sulfate, talc powder, diatomite, starch, urea.

[0021] When the bactericidal composition is made into a water dispersible granule, it contains the following components and percentage contents: pyraclostrobin 50 - 500 g, cyproconazole 50 - 300 g, synergist 10 - 100 g, dispersant 10 - 200 g, wetting agent 10 - 100 g, binder 1 - 100 g, defoamer 0 - 30 g, pH regulator 0 - 40 g, filler up to 1000 g.

[0022] Compared with the prior art, the bactericidal composition for preventing and controlling wheat rust of the present invention has the following beneficial effects: (1) Compared with single agents, the composition has a more significant effect on preventing and controlling wheat rust and has an obvious synergistic effect; (2) The mixing of two compounds with different action mechanisms can effectively delay the generation of disease resistance, and has good safety and is safe for wheat; (3) The bactericidal composition has protective and therapeutic effects. When used before the disease occurs, it can basically prevent the occurrence of the disease. When used in the initial stage of the disease, it can effectively control the disease and has good long-term efficacy, and the long-term efficacy can reach more than 20 days; (4) It can treat multiple diseases with one drug, can effectively prevent and control fungal diseases and bacterial diseases, and effectively reduce the drug cost of farmers; (5) It has the advantages of enhancing the immunity of crops, improving the stress resistance of crops, and promoting the growth of crops. Detailed Embodiments

[0023] The following further illustrates the present invention with reference to embodiments. The percentages in the embodiments are all weight percentages, but the present invention is not limited thereto.

[0024] Application Example 1

[0025] Example 1: 40% Pyraclostrobin · Cyproconazole Water Dispersible Granules

[0026] 250 g of pyraclostrobin technical, 150 g of cyproconazole, 25 g of a mixture of polyethoxylated modified silane and polyethoxylated modified fatty alcohol, 30 g of alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, 20 g of alkyl polyoxyethylene ether sulfonate, 30 g of sodium diisobutylnaphthalenesulfonate, 35 g of sorbitan fatty acid ester, 5 g of polyvinylpyrrolidone, 3 g of citric acid, 2 g of silicone defoamer, 30 g of ammonium sulfate, and urea added to 1000 g to obtain 40% pyraclostrobin · cyproconazole water dispersible granules.

[0027] Example 2: 50% Pyraclostrobin · Cyproconazole Water Dispersible Granules

[0028] 250 g of pyraclostrobin technical, 250 g of cyproconazole, 20 g of a mixture of polyethoxylated modified silane and polyethoxylated modified fatty alcohol, 20 g of EO-PO block polyether, 25 g of styrenephenol polyoxyethylene ether phosphate, 50 g of alkyl sulfate, 8 g of polyethylene glycol, 3 g of glacial acetic acid, 3 g of fatty alcohol, 20 g of white carbon black, and starch added to 1000 g to obtain 50% pyraclostrobin · cyproconazole water dispersible granules.

[0029] Example 3: 70% Pyraclostrobin · Cyproconazole Water Dispersible Granules

[0030] 500 g of pyraclostrobin technical, 200 g of cyproconazole, 30 g of alkoxy-modified polytrioxane, 25 g of alkylphenol polyoxyethylene ether formaldehyde condensate phosphate, 35 g of methylene dinaphthalenesulfonate, 40 g of triphenylethylphenol polyoxypropylene polyoxyethylene block polymer, 3 g of polyethylene glycol, 8 g of silicone defoamer, 10 g of potassium dihydrogen phosphate, 30 g of starch, and urea added to 1000 g to obtain 50% pyraclostrobin · cyproconazole water dispersible granules.

[0031] Example 4: 30% Pyraclostrobin · Cyproconazole Water Dispersible Granules

[0032] 150 g of pyraclostrobin technical, 150 g of cyproconazole, 2 g of alkoxy-modified polytrioxane, 30 g of alkylphenol polyoxyethylene ether sulfonate, 25 g of phenylethylphenol polyoxyethylene ether phosphate, 40 g of sodium dodecylbenzenesulfonate, 5 g of fatty alcohol, 2 g of polyvinyl alcohol, 2 g of citric acid, and potassium sulfate added to 1000 g to obtain 30% pyraclostrobin · cyproconazole water dispersible granules.

[0033] Application Example 2:

[0034] Virulence Determination of the Mixture of Pyraclostrobin and Cyproconazole against Wheat Rust

[0035] According to the standard of NY / T1156.15 - 2008, the toxicity of pyraclostrobin and cyproconazole and their mixtures at ratios of 1:1, 5:3, 2:1, 3:1, and 5:1 against wheat rust pathogens was determined by the method of medicated medium. The results showed that the mixtures of pyraclostrobin and cyproconazole at the above - mentioned 5 ratios exhibited synergistic effects on wheat rust pathogens. The experimental process is as follows: 1 Experimental purpose

[0036] The toxicity of pyraclostrobin and cyproconazole and their mixtures in different ratios against wheat rust pathogens was determined indoors, and the synergistic effect was evaluated to clarify their compatibility, providing a scientific basis for the research and development of the mixture of pyraclostrobin and cyproconazole.

[0037] 2 Experimental conditions

[0038] 2.1 Test target

[0039] Wheat rust pathogens.

[0040] 2.2 Cultivation conditions

[0041] The cultivation conditions for the test target and the target after the test were a temperature of 25 ± 5°C and a relative humidity of 65 ± 5% or more.

[0042] 2.3 Instrument and equipment

[0043] Beakers, pipettes, measuring cylinders, petri dishes, volumetric flasks, autoclaves, biochemical incubators, etc.

[0044] 3 Experimental design

[0045] 3.1 Test agents

[0046] Pyraclostrobin 97% technical; Cyproconazole 98% technical.

[0047] 3.2 Design of agent concentration and solution preparation

[0048] Pyraclostrobin solution: Weigh 0.0100 g of pyraclostrobin 97% technical with a sterilized small beaker, dissolve it with 0.2 mL of DMF, add 96.8 mL of sterile water containing 0.1% Tween80 emulsifier, stir evenly to prepare a 100 mg / L stock solution, and then dilute it with sterile water containing 0.1% Tween80 emulsifier to concentrations of 20, 10, 5, 1, 0.5, and 0.1 mg / L for standby;

[0049] Cyproconazole solution: Weigh 0.0400 g of 98% cyproconazole technical with a sterilized small beaker, dissolve it with 0.2 mL of DMF, add 94.8 mL of sterile water containing 0.1% Tween 80 emulsifier, stir evenly to prepare a 400 mg / L mother liquor, and then dilute it with sterile water containing 0.1% Tween 80 emulsifier to concentrations of 20, 10, 5, 1, 0.5, and 0.1 mg / L for standby;

[0050] Each mixed solution: Mix pyraclostrobin and cyproconazole in the ratios of 1:1, 5:3, 2:1, 3:1, and 5:1, and then dilute them with sterile water containing 0.1% Tween 80 emulsifier to concentrations of 10, 5, 1, 0.5, and 0.1 mg / L for standby;

[0051] Control solution: 0.2 mL of DMF plus 99.8 mL of sterile water containing 0.1% Tween 80 emulsifier.

[0052] 4 Test methods

[0053] Refer to the bioassay standard method NY / T1156.15 - 2008, and adopt the pot method. Spray inoculate with the spore suspension. For the protective test, inoculate 24 h after the chemical treatment; for the therapeutic test, inoculate 24 h before the chemical treatment; for the disease resistance activation test, inoculate 3 d - 7 d after the chemical treatment. After inoculating the wheat seedlings, cultivate them in the dark with moisture retention for more than 12 h. The optimum temperature required during the moisture retention stage is 15°C - 20°C, and then cultivate them in a greenhouse at 18°C - 22°C with more than 12 h of light per day. Each treatment has 4 replicates. After the treatment, place them in a constant temperature biochemical incubator at 28°C for cultivation. After 7 days, measure the colony diameter and calculate the growth inhibition rate.

[0054] 5 Data investigation and statistical analysis

[0055] 5.1 Investigation method

[0056] According to the investigation data, calculate the disease index and control effect of each treatment.

[0057] 5.2 Evaluation method for synergistic effect

[0058] Evaluate the synergistic effect of the chemical mixture according to the co - toxicity coefficient method (CTC) of Sun & Johnson (1960), that is, CTC ≤ 80 is antagonistic effect, 80 < CTC < 120 is additive effect, and CTC ≥ 120 is synergistic effect.

[0059]

[0060] The theoretical toxicity index (TTI) of the mixture = the toxicity index of chemical A × the percentage of chemical A in the mixture (%) + the toxicity index of chemical B × the percentage of chemical B in the mixture (%)

[0061]

[0062] 5.3 Data statistical analysis

[0063] All experimental data were analyzed using SAS 6.12 statistical software. The inhibition rate of mycelial growth (%) was calculated based on the experimental data, and the virulence regression equation, correlation coefficient (r), and EC50 (95% confidence limit) were obtained.

[0064] 6 Result analysis and discussion

[0065] 6.1 Efficacy evaluation

[0066] The results of the virulence determination of the mixed combinations of different ratios of pyraclostrobin and cyproconazole against wheat rust are shown in Table 1. As can be seen from Table 1, the mixtures of pyraclostrobin and cyproconazole at the ratios of 1:1, 5:3, 2:1, 3:1, and 5:1 all showed synergistic effects against Puccinia triticina, with EC50 values of 0.29, 0.41, 0.60, 0.71, and 1.01 mg / L, respectively, and co-toxicity coefficients of 121.98, 166.76, 157.56, 138.87, and 124.75, respectively. Among them, the mixture at the ratio of 1:6 had a better synergistic effect.

[0067] Table 1 Results of the virulence determination of the mixture of pyraclostrobin and cyproconazole against wheat rust

[0068]

[0069] 6.2 Discussion and conclusion

[0070] The results of the in vitro bioassay showed that the mixtures of pyraclostrobin and cyproconazole at the ratios of 1:1, 5:3, 2:1, 3:1, and 5:1 all showed synergistic effects against Puccinia triticina, and the best synergistic effect was obtained with the ratio of 5:3.

[0071] Application Example 3: Field efficacy experiment of Example 1 in controlling wheat rust

[0072] The test was carried out with reference to the "Guidelines for field efficacy trials of pesticides (I) 2004 - Guidelines for field efficacy trials of fungicides in controlling cereal rust".

[0073] Test crop: Wheat

[0074] Target pest: Rust

[0075] 1 Basic information of the test

[0076] 1.1 Test name

[0077] Field efficacy test of 40% pyraclostrobin·cyproconazole water dispersible granules against wheat rust.

[0078] 1.2 Test Objectives

[0079] To clarify the control effect, applicable dosage and safety of the 40% pyraclostrobin · cyproconazole water dispersible granule provided by the applicant against wheat rust, and to provide a basis for the registration and promotion of the test agent.

[0080] 2 Environmental and Facility Cultivation Conditions

[0081] 2.1 Test Location

[0082] Shaanxi Province

[0083] 2.2 Test Target Situation

[0084] Wheat rust (Phomopsis cytosporella)

[0085] 2.3 Test Crops, Varieties and Growth Conditions

[0086] The experimental crop is wheat. It is a susceptible variety to wheat rust, and the wheat growth is good.

[0087] 3 Test Design and Arrangement

[0088] 3.1 Test Dosage and Number

[0089] Table 2 Test Design of Test Agents

[0090] Treatment number Agent Active ingredient (g / ha) Dosage of formulation (g / mu) 1 40% Pyraclostrobin · Cyproconazole Water Dispersible Granules 6 15 2 50% Pyraclostrobin · Cyproconazole Water Dispersible Granules 6 12 3 70% Pyraclostrobin · Cyproconazole Water Dispersible Granules 7 10 4 30% Pyraclostrobin Suspension Concentrate 12 40 5 40% Cyproconazole Suspension Concentrate 6 15 6 Water control —— ——

[0091] 3.2 Application Method

[0092] 3.2.1 Application Period and Method

[0093] A total of 2 applications were made. The first application was made at the early jointing stage of wheat, and the second application was made 7 days later.

[0094] 3.2.2 Application Volume

[0095] Spraying, the water consumption for application was 750 L / ha.

[0096] 3.3 Investigation Method, Time and Frequency

[0097] 3.3.1 Investigation Time and Frequency

[0098] This test was investigated 2 times. The first investigation was the investigation of the disease incidence base before application, which was in the pre-disease stage, and the disease incidence base was 0. The second investigation time was to investigate the control effect 10 days after the second application.

[0099] 3.3.2 Investigation Method

[0100] Investigate 20 plants per plot, sample 5 points in the east, west, south, north and middle directions for each plant, and investigate three leaves for each plant. Leaf grading standard:

[0101] Grade 0: No lesions;

[0102] Grade 1: The lesion area accounts for less than 5% of the total leaf area;

[0103] Grade 3: The lesion area accounts for 6% - 10% of the total leaf area;

[0104] Grade 5: The lesion area accounts for 11% - 25% of the total leaf area;

[0105] Grade 7: The lesion area accounts for 26% - 50% of the total leaf area;

[0106] Grade 9: The lesion area accounts for more than 50% of the total leaf area.

[0107] 3.3.3 Efficacy calculation method

[0108]

[0109]

[0110] Note: CK0 - Disease index of the blank control area; PT0 - Disease index of the treatment area.

[0111] 4 Results and analysis

[0112] Table 3 Test results of Examples 1 - 3 for controlling wheat rust 1

[0113]

[0114] The investigation results on the 10th day after the last application showed that the average disease indices in the treatment areas of each agent were between 1.63 - 2.22, and the average disease index in the clear water control treatment area was 8.02. The control effect of the test agents was significantly better than that of the control single agent and had excellent significance.

Claims

1. Use of a bactericidal composition for controlling wheat rust, characterized in that: The active ingredients of the bactericidal composition are pyraclostrobin and cyproconazole, and the weight ratio of pyraclostrobin to cyproconazole is 5:1 to 1:

1.

2. The use according to claim 1, characterized in that: The bactericidal composition contains pyraclostrobin, cyproconazole, synergist, silica white mixture and adjuvant, and is made into a water dispersible granule.

3. The use according to claim 1 or 2, characterized in that: The weight ratio of pyraclostrobin to cyproconazole is 3:1 to 1:

1.

4. The use according to claim 3, characterized in that: The weight ratio of pyraclostrobin to cyproconazole is 5:

3.

5. The use according to any one of claims 1 to 4, characterized in that: The total weight of pyraclostrobin and cyproconazole in the bactericidal composition is 20% to 77%.

6. The use according to claim 5, wherein: The total weight of pyraclostrobin and cyproconazole in the bactericidal composition is 50%.

7. The use according to claim 2, wherein: The adjuvant is selected from one or more of dispersant, wetting agent, binder, defoamer, pH regulator, filler.

8. The use according to any one of claims 1 to 7, characterized in that: The dosage of the active ingredient of the bactericidal composition is 3 - 50 grams per hectare.

Images