Bactericidal composition for preventing and treating corn ear rot and application thereof

Abstract

The invention relates to a bactericidal composition for preventing and treating corn ear rot and application of the bactericidal composition, and belongs to the technical field of pesticide compounding. The sterilization composition is prepared from the meconazole and the metconazole, and the weight ratio of the meconazole to the meconazole is (1: 2) to (2: 1). The bactericidal composition has the characteristics of high efficiency, low toxicity, low residue, long lasting period, safety to crops and environmental friendliness; the compound has a remarkable inhibition effect on corn ear rot and pathogenic microorganisms thereof, can remarkably reduce the pollution level of FBs toxins in grains, and has a relatively good prevention and treatment effect in the field; furthermore, the bactericidal composition can effectively delay the generation of drug resistance of pathogenic bacteria and reduce the input amount of pesticides, and has remarkable economic benefits and social benefits.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide compounding, and in particular to a bactericidal composition for preventing and controlling corn ear rot and application thereof. Background Art

[0002] Corn (Zeamays L.), as one of the important crops, is widely planted around the world. It is an important food, feed and industrial raw material in the world today. The improvement of its yield and quality is of vital importance to agricultural development. In recent years, with the increase in corn planting area and the continuous introduction of various corn varieties that can be used as both food and feed, corn varieties have been constantly replaced, and the straw return technology has been continuously promoted, making the impact of diseases on corn yield increasingly serious.

[0003] Maize ear rot (Fusarium Maize Ear Rot, FER) is a serious fungal disease that occurs in the late stage of maize growth. It not only reduces maize yield, but also causes fungal toxin pollution, seriously affects maize quality, and even threatens human and animal health. Fusarium verticillioide is the main pathogen of maize ear rot. At present, the prevention and control strategies of maize ear rot are still very limited. The prevention and control of this disease in production mainly focuses on planting disease-resistant varieties and applying chemical agents. However, no maize genotype with absolute resistance to Fusarium verticillioide has been found worldwide. Furthermore, although spraying chemical fungicides can significantly reduce the incidence and toxin pollution of maize ear rot, no special fungicide for the prevention and control of maize ear rot has been found. Therefore, there is an urgent need to develop a low-toxic and efficient fungicide for the prevention and control of Fusarium verticillioide infection to effectively and sustainably control the occurrence of maize ear rot. Summary of the invention

[0004] The purpose of the present invention is to provide a fungicide composition for preventing and controlling corn ear rot and its application, to make up for the deficiencies of the prior art and solve the problem that corn ear rot occurs seriously but there is no special fungicide.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a fungicide composition for preventing and controlling corn ear rot. The fungicide composition comprises cypermethrin and metconazole, and the weight ratio of cypermethrin to metconazole is (1:2) to (2:1).

[0007] The invention also provides application of the bactericidal composition in preparing a bactericide.

[0008] The present invention also provides a bactericide containing the bactericide composition, wherein the bactericide comprises the bactericide composition and an auxiliary agent.

[0009] Preferably, the weight percentage of the bactericidal composition in the bactericide is 20% to 50%.

[0010] Preferably, the fungicide is in the form of emulsifiable concentrate, wettable powder, suspension, aqueous emulsion, microemulsion or water-dispersible granules.

[0011] Preferably, the auxiliary agent includes one or a mixture of emulsifiers, wetting agents, stabilizers, dispersants, thickeners, defoamers, antifreeze agents, fillers, and media.

[0012] The present invention also provides the use of the bactericidal composition or the bactericide in inhibiting the growth of microorganisms.

[0013] Preferably, the microorganism comprises Fusarium verticillium.

[0014] The present invention also provides application of the bactericidal composition or the bactericide in preventing and treating corn ear rot.

[0015] The beneficial effects of the present invention are:

[0016] (1) The fungicidal composition of the present invention, cypermethrin and metconazole, has a significant synergistic effect after being mixed, which improves the control effect and is also helpful in overcoming and delaying the development of drug resistance of the disease.

[0017] (2) The fungicide composition prepared by mixing clofodinate and metconazole in the present invention can significantly inhibit the occurrence of diseases, reduce the FBs toxin content in corn kernels at harvest time and increase corn yield, and has a significant effect in preventing and controlling corn ear rot.

[0018] (3) The compounding of the composition of the present invention reduces the dosage of the pesticide, thereby reducing the cost and reducing the pollution to the environment. It has good safety and meets the safety requirements of pesticide preparations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The field control effect of clofoconazole, metconazole and their combination on corn ear rot. DETAILED DESCRIPTION

[0020] The present invention provides a fungicide composition for preventing and controlling corn ear rot. The fungicide composition comprises cypermethrin and metconazole. The weight ratio of cypermethrin to metconazole is preferably (1:2) to (2:1), and more preferably 1:2.

[0021] The invention also provides application of the bactericidal composition in preparing a bactericide.

[0022] The present invention also provides a bactericide containing the bactericide composition, wherein the bactericide comprises the bactericide composition and an auxiliary agent.

[0023] In the present invention, the weight percentage of the bactericidal composition in the bactericide is preferably 20% to 50%, more preferably 30% to 45%, and even more preferably 40%.

[0024] In the present invention, the fungicide is in the form of emulsifiable concentrate, wettable powder, suspension, aqueous emulsion, microemulsion or water-dispersible granules.

[0025] In the present invention, the auxiliary agent includes one or a mixture of emulsifiers, wetting agents, stabilizers, dispersants, thickeners, defoamers, antifreeze agents, fillers, fillers and media;

[0026] The dispersant is selected from polycarboxylates, alkylphenol polyoxyethylene ethers, lignin sulfonates, methyl ether condensate sulfates, naphthalenesulfonic acid formaldehyde condensate sodium salts, alkyl sulfonate calcium salts, alkylphenol polyoxyethylene ethers, glycerol fatty acid ester polyoxyethylene ethers, fatty acid polyoxyethylene esters, or a mixture of any of the above;

[0027] The antifreeze agent is selected from one or more of ethylene glycol, glycerol, and propylene glycol;

[0028] The thickener is selected from one or more of xanthan gum, carboxymethyl cellulose, magnesium aluminum silicate, carboxyethyl cellulose, methyl cellulose, and polyvinyl alcohol;

[0029] The defoaming agent is selected from one or more of silicone oil, C8-10 fatty alcohol, silicone compound, C10-20 saturated fatty acid compound.

[0030] The present invention also provides the use of the bactericidal composition or the bactericide in inhibiting the growth of microorganisms.

[0031] In the present invention, the microorganism includes Fusarium verticillium.

[0032] The fungicide composition or the fungicide described in the present invention is used in preventing and treating corn ear rot.

[0033] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0034] The mass parts of each component in the cypermethrin suspension described in the embodiment are: 1-30 parts of cypermethrin; 5-30 parts of polycarboxylate (dispersant); 1-8 parts of ethylene glycol (antifreeze); 0.1-10 parts of xanthan gum (thickener); 0.1-10 parts of silicone oil (defoamer); 50-200 parts of water. First, all the materials are mixed, mixed evenly by high-speed shearing, and ground in a sand mill for 2-3 hours to make the particle size of the particles below 5 μm, and then the cypermethrin suspension can be prepared.

[0035] The mass parts of each component in the metconazole suspension described in the embodiment are: 1-30 parts of metconazole; 5-30 parts of alkylphenol polyoxyethylene ether (dispersant); 1-8 parts of propylene glycol (antifreeze agent); 0.1-10 parts of magnesium aluminum silicate (thickener); 0.1-10 parts of silicone compound (defoaming agent); 50-200 parts of water. First, all the materials are mixed, mixed evenly by high-speed shearing, and ground in a sand mill for 2-3 hours to make the particle size of the particles below 5μm, and then the metconazole suspension can be prepared.

[0036] The concentration of cypermethrin described in the embodiment is 1 μg / mL, and the preparation method is to dissolve 98.86% cypermethrin original powder purchased from Dr. Ehrenstorfer in acetone to prepare a single-dose mother solution with a concentration of 1 μg / mL cypermethrin.

[0037] The concentration of metconazole described in the embodiment is 1 μg / mL, and the preparation method is to dissolve 97% metconazole original powder purchased from Wuhan Xinru Chemical Co., Ltd. in acetone to prepare a single-dose mother solution of metconazole with a concentration of 1 μg / mL.

[0038] Example 1 Indoor toxicity determination of clofoconazole, metconazole and their mixtures against corn ear rot pathogen.

[0039] (1) Test reagents

[0040] According to the results of the preliminary test, on the basis of the above-mentioned single-dose mother solution, appropriate amounts of the two original drugs were prepared into three different ratios of mixtures, and then diluted with acetone to prepare six series of mass concentration solutions for use. The dilution of clofoconazole was 0, 0.01, 0.05, 0.1, 0.5 and 1 μg / mL; the dilution of metconazole was 0, 0.01, 0.05, 0.1, 0.5 and 1 μg / mL; the three different ratios of clofoconazole and metconazole (the weight ratio of the active ingredients was 1:1, 1:2 and 2:1) were diluted to 0, 0.01, 0.05, 0.1, 0.5 and 1 μg / mL respectively.

[0041] (2) Test materials

[0042] Representative strains of Fusarium verticillioides SD19-3 and JS20-15 were collected, isolated and identified from diseased corn ears by the Institute of Agricultural Product Quality, Safety and Nutrition of Jiangsu Academy of Agricultural Sciences and stored in the laboratory for future use. The strains were stored on potato sucrose agar (PDA) slants (4°C). After being transferred once on PDA medium plates in the laboratory, they were pre-cultured at 25°C for 3 days, and a 5 mm diameter cake was taken from the edge of the colony and inoculated into PDA medium. The corn ear rot pathogen was cultured at a temperature of 25°C and a photoperiod of L:D=12:12h (L is the light time, D is the dark time).

[0043] (3) Test methods

[0044] The tested cypermethrin, metconazole, and cypermethrin combined with metconazole were added to sterile potato dextrose agar (PDA) in a gradient manner to prepare a series of drug-containing culture media with concentrations of 0, 0.01, 0.05, 0.1, 0.5 and 1 μg / mL. Two single agents and three combined agents were respectively prepared into six different concentrations of drug-containing culture media, and each concentration treatment was repeated three times. The indoor biological activity of cypermethrin, metconazole and their combined agents against corn ear rot pathogen was determined by the mycelial growth rate method. Under sterile conditions, when the diameter of the activated corn ear rot bacteria reached 6 cm, holes were punched along the edge of the colony to obtain bacterial cakes with a diameter of 5 mm, which were inoculated onto PDA plates containing different gradient concentrations of the drug and cultured in an incubator at 25 °C for 72 h. When the control colony grew to 4 / 5 of the culture dish, the diameter of each colony was measured by the cross method, the average was taken and the growth inhibition rate was calculated. The calculation method is shown in Formula 1.

[0045] (4) Calculation formula

[0046] The growth inhibition rate was regressed against the logarithmic value of the concentration of the agent using the IBM SPSS Statistics 25 software program to calculate the fungicide concentration that resulted in a 50% inhibition rate of mycelial growth (EC 50 ), the calculation method is shown in Formula 2.

[0047]

[0048] The combined toxicity of the compound agent against Fusarium verticillium was evaluated according to the Wadley method, and the synergistic ratio (SR) was calculated. The calculation method is shown in Formula 3. The effect of the compound agent was analyzed according to the SR value, that is, SR < 0.5 represents antagonism, 0.5 ≤ SR ≤ 1.5 represents additive effect, and SR > 1.5 represents synergistic effect.

[0049]

[0050]

[0051] Note: In the formula, A and B are the compound agent components clofoconazole and metconazole respectively; a and b are the content proportions of clofoconazole and metconazole in the compound agent respectively.

[0052] (5) Test results

[0053] Table 1 Sensitivity of Fusarium verticillium to fluazifop-conazole and metconazole alone and in combination

[0054]

[0055] Note: In the table, A represents a single agent of fluconazole; B represents a single agent of metconazole; M1 represents a mixture of fluconazole: metconazole = 1:1; M2 represents a mixture of fluconazole: metconazole = 1:2; M3 represents a mixture of fluconazole: metconazole = 2:1.

[0056] The Wadley method was used to evaluate the combined toxicity of three combinations of clofoconazole and metconazole against Fusarium verticillium. As shown in Table 1, the experimental EC values ​​of the three combinations were 50 The values ​​were all less than 0.02 μg / mL, showing a strong toxic effect on Fusarium sphaerocephala; among them, when clofoconazole·metconazole (1:1), the average SR was 0.89, and the two fungicides had an additive effect; when clofoconazole·metconazole (2:1), the average SR was 1.58, and the two fungicides had a synergistic effect; when clofoconazole·metconazole (1:2), the average SR was 2.00, and the two fungicides had a synergistic effect, and the synergistic effect was the best among the three combinations, so it will be further used in field experiments to determine the field effect of the combination.

[0057] Example 2: Field control effects of cyfluthrin, metconazole and their mixtures on corn ear rot.

[0058] (1) Test materials

[0059] Corn, variety Deka 1210, was provided by the College of Plant Protection, Anhui Agricultural University.

[0060] Agents: 40% prothioconazole + tebuconazole suspension concentrate (prothioconazole + tebuconazole 40% SC) was provided by Jiangsu Liyang Zhongnan Chemical Co., Ltd. as a control agent for field control experiments; 20% clofoconazole SC, 20% metconazole SC and 20% clofoconazole + metconazole SC were independently developed by the Institute of Agricultural Product Quality, Safety and Nutrition of Jiangsu Academy of Agricultural Sciences and used in field agent control experiments; the agent contents are all mass percentages.

[0061] (2) Test methods

[0062] A field efficacy experiment was conducted in Nanjing, Jiangsu Province in 2022. The corn variety used in the field experiment was Deka 1210, and the planting density was 240 plants / hm2. 2 The experiment set up the following 6 treatments (all with active ingredient dosage): 20% clofoconazole SC 150, 225 and 300 g / hm 2 , 20% chlorfenapyr·metconazole (1:2) SC 150g / hm 2 , 40% prothioconazole·tebuconazole (1:1) SC 300g / hm 2 The same volume of water was used as a blank control. Each treatment was repeated 3 times, and the plot area was 16m 2 , arranged in random blocks. The ear of corn was sprayed manually during the tasseling period, and the spraying was performed once. After the corn matured, samples were taken from five diagonal points in each plot, and 10 ears were randomly harvested at each point, with a total of 50 ears in each plot. The disease situation was investigated, and the disease was graded according to the percentage of dead ear area to the total area of ​​investigated ears. The number of diseased ears and the total number of ears at each level were recorded from 0 (no obvious symptoms) to 9 (complete necrosis and damage), and the disease index (calculation method is shown in formula 4) and relative control effect (calculation method is shown in formula 5) were calculated. The investigated corn ears were naturally dried, threshed and mixed, and the thousand-grain weight was measured to calculate the yield increase rate; then the corn kernels were ground into powder, and the samples were pre-treated for toxin extraction using the QuEChERS method. 5g of corn powder was weighed into a 50mL centrifuge tube, 20mL of 80% acetonitrile (containing 0.1% formic acid) was added, and after oscillation extraction at 2500rpm for 30min, a corn toxin extraction salt bag (4g MgSO 4 , 1g NaCl, 1g Na 3 Citrate, 0.5gNa 2 HCitrate), 2500rpm shaking extraction for 2min, 10000rpm centrifugation for 5min, aspirate 2mL of supernatant, blow dry with nitrogen blower, re-dissolve with 50% acetonitrile (containing 0.01% formic acid), filter through 0.22μm organic phase membrane, and detect fumonisin B in the sample by HPLC-MS / MS 1 , B 2 and B 3 (FBs) toxin content.

[0063] (3) Survey methods for the occurrence of corn ear rot

[0064] Five points were selected diagonally near the middle of the experimental plot, and 10 ears were randomly harvested at each point, with a total of 50 ears in each plot. The number of diseased ears at each level of corn ear rot was recorded to calculate the disease index and relative control effect of corn ear rot. The experimental data were analyzed using Microsoft Excel 2010 and IBM SPSSStatistics 25 software. Method for classifying the disease level of corn ear rot:

[0065] Level 0: The whole ear is disease-free;

[0066] Level 1: The diseased area accounts for 0-1% of the whole ear area;

[0067] Level 3: The diseased area accounts for 2-10% of the whole ear area;

[0068] Level 5: The diseased area accounts for 11-25% of the whole ear area;

[0069] Level 7: The diseased area accounts for 26-50% of the whole ear area;

[0070] Level 9: The diseased area accounts for 51% to 100% of the total ear area.

[0071]

[0072]

[0073] (4) HPLC-MS / MS Detection Method for Fumonisins in Corn Kernels

[0074] Instrument conditions: Liquid phase conditions: Chromatographic column: AgilentXDB C18 (3.5μm, 2.1×150mm), flow rate 0.4mL / min; injection volume: 3μL; column temperature: 40℃; gradient elution conditions: aqueous phase A: 0.1% formic acid water, organic phase B: pure methanol; [0~0.5)min: 10% B; [0.5~2.0)min: 50% B; [2.0~4.0)min: 60% B; [4.0~5.0)min: 95% B; [5.0~8.0)min: 95% B; [8.0~8.1)min: 10% B; [8.1~10)min: 10% B. Mass spectrometry conditions: ionization mode: electrospray ion source (ESI+); scanning mode: multiple reaction monitoring mode (MRM); ion source temperature 600°C; nebulizer gas 55psi; auxiliary gas 60psi; curtain gas 30psi; spray voltage: 5500V; collision chamber ejection voltage: 10V; the mass spectrometry condition parameters of fumonisin are shown in Table 2.

[0075] Table 2 Main mass spectrometry parameters of fumonisins

[0076]

[0077] (5) Test results

[0078] The results of the field test showed that compared with the blank control group, spraying of clofoconazole alone and in combination during the tasseling period of corn significantly reduced the incidence of corn ear rot and increased corn yield ( Figure 1 A) Among them, 20% chlorfenapyr SC effective content 150, 225 and 300g / hm 2 The control effects of the treatment groups were 21.63%, 29.44% and 48.94% respectively. The effective content of 20% cypermethrin·metconazole (1:2) SC was 150g / hm 2 The control efficacy of the treatment group was 44.49%, while the effective content of the control agent 40% prothioconazole·tebuconazole (1:1) SC was 300g / hm 2 The control effect of the treatment group was 24.35% ( Figure 1 B). At the same time, 150, 225 and 300g / hm 2 After treatment with cypermethrin, corn yield increased by 7.16%, 15.56%, and 26.54%, respectively; after treatment with cypermethrin and metconazole, corn yield increased by 18.34%, and after treatment with prothioconazole and tebuconazole, corn yield increased by 9.70%. Figure 1 C).

[0079] In addition, compared with the treatment with prothioconazole and tebuconazole (the inhibition rate was 34.10% in 2022), 150, 225 and 300 g / hm 2 The FBs content in corn kernels was reduced by 46.19%, 52.35%, and 64.47% respectively when treated with 150 g / hm2 of cyfluthrin and metconazole. 2 Treatment reduced the FBs content in corn kernels by 54.62% ( Figure 1 D).

[0080] Note: Figure 1 CK is a blank control; T1 is a 20% chlorfenapyr suspension, with an effective content of 150 g / hm2 2 ; T2 is 20% chlorfenapyr suspension, effective content 225g / hm 2 ; T3 is 20% chlorfenapyr suspension, effective content 300g / hm 2 ; T4 is a 20% suspension of fluazifop-butyl and metconazole (1:2), with an effective content of 150g / hm 2 ; T5 is a 40% prothioconazole·tebuconazole (1:1) suspension, with an effective content of 300g / hm 2 Different lowercase letters after the data in the same group indicate significant differences at the P < 0.05 level as tested by Duncan's new multiple range method.

[0081] Field experiments were conducted to analyze the control effects of clofoconazole alone and in combination on corn ear rot and FBs contamination. Spraying treatments with three effective concentrations of clofoconazole alone and in combination significantly reduced the incidence of corn ear rot, and the control effects were significantly higher than those with an effective concentration of 300 g / hm2. 2 The commonly used fungicide prothioconazole·tebuconazole is safe for corn within the dosage range (no obvious phytotoxicity was observed when observing corn growth with the naked eye); the control effect of the compound agent is better than that of a single agent, thus verifying its synergistic effect. The corn yield and toxin inhibition rate treated with clofoconazole were higher than those treated with prothioconazole·tebuconazole. Therefore, the field experiment results show that, considering the control effect and dosage, 20% clofoconazole·metconazole (1:2) SC 150g / hm 2 It can be used as a fungicide to prevent and control corn ear rot.

[0082] As can be seen from the above embodiments, the present invention provides a fungicide composition for preventing and controlling corn ear rot and its application. The present invention uses clofoconazole and metconazole in combination, which has a significant control effect on corn ear rot, significantly reduces the contamination of FBs toxins in corn kernels, and can greatly reduce the dosage of traditional triazole fungicides under the same control effect, overcome or delay the drug resistance of pests, and has the advantages of safety, environmental protection, and reduced environmental pollution.

[0083] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fungicidal composition for preventing and controlling corn ear rot, characterized in that: The fungicide composition comprises cypermethrin and metconazole, and the weight ratio of cypermethrin to metconazole is (1:2) to (2:1).

2. Use of the bactericidal composition according to claim 1 in the preparation of a bactericide.

3. A bactericide containing the bactericidal composition according to claim 1, characterized in that: The bactericide comprises the bactericidal composition according to claim 1 and an auxiliary agent.

4. The bactericide according to claim 3, characterized in that The weight percentage of the bactericidal composition in the bactericide is 20% to 50%.

5. The bactericide according to claim 4, characterized in that The dosage form of the fungicide is emulsifiable concentrate, wettable powder, suspension, aqueous emulsion, microemulsion or water-dispersible granule.

6. The fungicide according to claim 5, characterized in that The auxiliary agent includes one or a mixture of emulsifier, wetting agent, stabilizer, dispersant, thickener, defoamer, antifreeze agent, filler, filler and medium.

7. Use of the bactericidal composition according to claim 1 or the bactericide according to any one of claims 3 to 6 in inhibiting the growth of microorganisms.

8. The use according to claim 7, characterized in that: The microorganisms include Fusarium verticillium.

9. Use of the fungicide composition according to claim 1 or the fungicide according to any one of claims 3 to 6 in preventing and controlling corn ear rot.

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