Bactericidal composition for preventing and treating peanut southern blight

Abstract

The invention belongs to the technical field of prevention and treatment of peanut southern blight, and particularly relates to a bactericidal composition for preventing and treating peanut southern blight. The invention relates to a sterilization composition. The effective component of the sterilization composition is formed by compounding butylphthalide and pyraclostrobin or tebuconazole according to the mass ratio of (1-150): (150-1). After the butylphthalide and the pyraclostrobin or the tebuconazole are compounded according to a certain mass ratio, the activity of the compounded formula is not simply superposed, but shows a very good synergistic effect. Compared with single pyraclostrobin or tebuconazole, the composition has the advantages that the prevention and treatment effect on the peanut southern blight can be improved, and on the basis, the dosage of medicaments can be reduced, and the environmental pollution can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of peanut southern blight control, and specifically relates to a bactericidal composition for controlling peanut southern blight. Background Art

[0002] Peanut southern blight, also known as stem rot and southern blight. The anamorph of the peanut southern blight pathogen is Sclerotium rolfsii Sacc., and the teleomorph is Athelia rolfsii Cruzi. Peanut southern blight can infect all growth cycles of peanuts, mainly attacking the stem base, fruit stalk, pod, and root of peanuts. In the initial stage of the disease, the main stem and lateral branches of the plant turn yellow and wilt, and white silk-like mycelia grow at the stem base near the soil; in the later stage of the disease, the stem base tissue rots into a fibrous state, the leaves turn yellow and wither, and the plant withers and dies; at the same time, the white mycelia aggregate with each other to produce a large number of rapeseed-like sclerotia, and the sclerotia gradually change from white to yellowish-brown and finally turn dark brown. In recent years, affected by factors such as climate warming, high-density planting, and straw returning to the field, peanut southern blight has been increasing year by year in most peanut production areas.

[0003] Currently, chemical control is still the main method for controlling peanut southern blight. Fungicides such as hexaconazole, difenoconazole, fludioxonil, thifluzamide, propiconazole, and flutolanil have good control effects on peanut southern blight. However, due to the single action target of single-component fungicides, long-term use is likely to cause problems such as pathogen resistance, excessive pesticide residues, and environmental pollution. Compounding different fungicide components, a compound formulation with a synergistic effect can effectively overcome the problems existing in the above single-component fungicides.

[0004] Butylphthalide is one of the chemical components of Chuanxiong essential oil, CAS: 6066-49-5, molecular formula: C 12 H 14 O2, and the structural formula is as follows:

[0005]

[0006] CN114766487B discloses the application of butenylphthalide and butylphthalide in controlling crop southern blight. The toxicity of butenylphthalide and butylphthalide to the mycelial growth of Sclerotium rolfsii was measured by the mycelial growth rate method, which were 14.0 mg / L and 32.3 mg / L respectively. It can be seen that butenylphthalide and butylphthalide have good application prospects in controlling crop southern blight caused by Sclerotium rolfsii.

[0007] There is no relevant report on the compounding of butylphthalide with pyraclostrobin or tebuconazole yet.

[0008] The information disclosed in this background section is only intended to enhance the general understanding of the background of the present invention and should not be regarded as an admission or any form of implication that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0009] The object of the present invention is to provide a bactericidal composition for controlling Sclerotium rolfsii of peanuts, so as to solve the problems existing in the long-term use of single-component fungicides.

[0010] To achieve the above object, the present invention provides the following technical solutions:

[0011] A bactericidal composition, wherein the active ingredients of the bactericidal composition are compounded by butylphthalide and pyraclostrobin or tebuconazole in a mass ratio of 1 - 150:150 - 1.

[0012] Preferably, the mass ratio of butylphthalide to pyraclostrobin is 1 - 30:20 - 1.

[0013] Preferably, the mass ratio of butylphthalide to tebuconazole is 1 - 15:45 - 1.

[0014] The present invention also provides a fungicide, which is composed of auxiliary ingredients and the above-mentioned bactericidal composition.

[0015] The present invention also provides the application of the above-mentioned bactericidal composition or the above-mentioned fungicide in controlling Sclerotium rolfsii of peanuts or in preparing agents for controlling Sclerotium rolfsii of peanuts.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) After compounding butylphthalide and pyraclostrobin or tebuconazole in a certain mass ratio in the present invention, the activity of the compounded formulation is not simply additive, but shows a good synergistic effect. Compared with single pyraclostrobin or tebuconazole, it can improve the control effect on Sclerotium rolfsii of peanuts. On this basis, the dosage of the agent can be reduced, and environmental pollution can be reduced.

[0018] (2) After compounding two different bactericidal active ingredients in the present invention, it can act on different action sites of the pathogen, effectively alleviate the generation and development of pathogen drug resistance, and thus can overcome the problems existing in the long-term use of single-component fungicides to a certain extent. Detailed Embodiments

[0019] The technical solutions of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0020] Examples : Screening of Compound Preventive and Therapeutic Agents of Butylphthalide

[0021] 1. Test Strains

[0022] Sclerotia were collected from peanut fields with typical symptoms of southern blight of peanut, and were isolated, purified and verified by Koch's postulates in the laboratory. The pathogenic bacterium was confirmed as Sclerotium rolfsii Sacc. and was preserved on PDA medium.

[0023] The test strains were inoculated in the center of PDA medium and propagated and cultured for 2 d under dark conditions at 25 °C for standby.

[0024] 2. Test Agents

[0025] 98% butylphthalide technical, 97.5% pyraclostrobin technical and 96% tebuconazole technical. All the above agents are commercially available.

[0026] The test agents were completely dissolved with dimethyl sulfoxide and then diluted with 0.1% Tween-80 aqueous solution to form single-agent stock solutions. Multiple groups of ratios were set, and each single-agent stock solution and the mixed agent of the ratio were further diluted with 0.1% Tween-80 aqueous solution to set 5 mass concentration gradients.

[0027] 3. Test Methods

[0028] The mycelial growth rate method was used to determine the virulence of the single-agent stock solutions and the mixed agents of the ratios against the test strain Sclerotium rolfsii. Specifically, 1 mL of the liquid medicine was fully mixed with 9 mL of pre-melted PDA medium, and then poured into a petri dish with a diameter of 9 cm and cooled to form a drug-containing plate;. A 5-mm-diameter mycelial disc was cut from the edge of the colony of the test strain after propagation with a puncher and placed in the center of the drug-containing plate and the blank control plate. After covering the petri dish lid, it was cultured under dark conditions at 25 °C, with 5 replicates for each treatment. When the colony diameter of the blank control grew to 6 - 7 cm, the colony diameter was measured by the cross method, and the mycelial growth inhibition rate of different treatments was calculated.

[0029]

[0030] 4. Data Analysis

[0031] DPS software was used for data statistical analysis. The logarithm value of the fungicide concentration was used as x, and the probit value of the corresponding mycelial growth inhibition rate was used as y for linear regression to obtain the virulence regression equation and the EC 50 value of the agent against the target pathogen, and the co-toxicity coefficient (CTC) was calculated according to Sun Yunpei method.

[0032]

[0033] In the above formula: ATI--the measured toxicity index of the mixture; S--the EC of the standard agent 50 , with the unit of mg / L; M--the EC of the mixture 50 , with the unit of mg / L.

[0034] TTI = TI A ×P A +TI B ×P B

[0035] In the above formula: TTI--the theoretical toxicological index of the mixture; TI A --the toxicity index of agent A; P A --the percentage content of agent A in the mixture, with the unit of percentage (%); TI B --the toxicity index of agent B; P B --the percentage content of agent B in the mixture, with the unit of percentage (%).

[0036]

[0037] In the above formula: CTC--the co-toxicity coefficient; ATI--the measured toxicity index of the mixture; TTI--the theoretical toxicity index of the mixture.

[0038] 5. Determination results

[0039] The synergistic effect of the agent is evaluated according to the calculated co-toxicity coefficient (CTC). When CTC ≤ 80, it is antagonistic effect; when 80 < CTC < 120, it is additive effect; when CTC ≥ 120, it is synergistic effect. The results are shown in Table 1-2.

[0040] Table 1 Toxicity determination results of the compound of butylphthalide and pyraclostrobin against Sclerotium rolfsii of peanut

[0041] Name and ratio of medicaments EC50 (mg / L) ATI TTI CTC Butylphthalide 24.7405 100.0000 -- -- Pyraclostrobin 4.5281 546.3771 -- -- Butylphthalide 1:Pyraclostrobin 20 3.2674 757.1923 525.1210 144.1939 Butylphthalide 1:Pyraclostrobin 10 2.4505 1009.6103 505.7973 199.6077 Butylphthalide 1:Pyraclostrobin 5 4.0809 606.2511 471.9809 128.4482 Butylphthalide 1:Pyraclostrobin 1 6.3549 389.3138 323.1885 120.4603 Butylphthalide 5:Pyraclostrobin 1 8.2882 298.5027 174.3962 171.1636 Butylphthalide 10:Pyraclostrobin 1 13.7593 179.8093 140.5797 127.9056 Butylphthalide 15:Pyraclostrobin 1 15.6719 157.8654 127.8986 123.4301 Butylphthalide 30:Pyraclostrobin 1 10.5954 233.5023 114.3993 204.1117

[0042] As can be seen from Table 1, after the compounding of the active ingredients butylphthalide and pyraclostrobin, the co-toxicity coefficients against Sclerotium rolfsii of peanut are all greater than 120 in the mass ratio range of 1-30:20-1, showing a synergistic effect.

[0043] Table 2 Toxicity determination results of the compound of butylphthalide and tebuconazole against Sclerotium rolfsii of peanut

[0044] Name and ratio of medicaments EC50 (mg / L) ATI TTI CTC Butylphthalide 24.7405 100.0000 -- -- Tebuconazole 2.6539 932.2318 -- -- Butylphthalide 1:Tebuconazole 45 1.1284 2192.5292 914.1398 239.8462 Butylphthalide 1:Tebuconazole 30 0.8849 2795.8526 905.3856 308.8024 Butylphthalide 1:Tebuconazole 15 1.8569 1332.3550 880.2173 151.3666 Butylphthalide 1:Tebuconazole 10 2.0015 1236.0979 856.5744 144.3071 Butylphthalide 1:Tebuconazole 5 2.2447 1102.1740 793.5265 138.8957 Butylphthalide 1:Tebuconazole 1 3.8313 645.7469 516.1159 125.1166 Butylphthalide 5:Tebuconazole 1 7.4841 330.5742 238.7053 138.4863 Butylphthalide 10:Tebuconazole 1 8.3554 296.1019 175.6574 168.5678 Butylphthalide 15:Tebuconazole 1 5.0943 485.6506 152.0145 319.4765

[0045] As can be seen from Table 2, after the compounding of the active ingredients butylphthalide and tebuconazole, the co-toxicity coefficients against Sclerotium rolfsii of peanut are all greater than 120 in the mass ratio range of 1-15:45-1, showing a synergistic effect.

[0046] In summary, the combination of butylphthalide and pyraclostrobin or tebuconazole has a good synergistic effect. Compared with single pyraclostrobin or tebuconazole, it can improve the control effect of peanut white rot. On this basis, it can reduce the dosage of pesticides and reduce environmental pollution.

[0047] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A bactericidal composition, characterized in that, The active ingredient of the bactericidal composition is prepared by compounding butylphthalide with pyraclostrobin or tebuconazole according to a mass ratio of 1-150:150-1.

2. The bactericidal composition according to claim 1, wherein The mass ratio of butylphthalide to pyraclostrobin is 1-30:20-1.

3. The bactericidal composition according to claim 1, characterized in that, The mass ratio of butylphthalide to tebuconazole is 1-15:45-1.

4. A fungicide, characterized in that, The bactericide is composed of auxiliary ingredients and the bactericidal composition according to any one of claims 1-3.

5. Use of the bactericidal composition according to claim 1 or the bactericide according to claim 4 in controlling southern blight of peanut or in preparing a medicament for controlling southern blight of peanut.

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