A highly active fungicide for preventing and controlling field diseases

Abstract

The present invention belongs to the technical field of pesticides, and particularly relates to a highly active fungicide for controlling field diseases. A highly active fungicide for controlling field diseases, the active ingredient of which is composed of thifluzamide and parthenolide in a compound form, and the compound mass ratio is 1-200:200-1. When the active ingredients thifluzamide and parthenolide in the pesticide composition of the present invention are compounded, the co-toxicity coefficient is greater than 120 within a certain mass ratio range, showing a synergistic effect. Based on this, the pesticide composition of the present invention can effectively control sheath blight of rice, and compared with a single agent, it can improve the control effect on sheath blight of rice, is beneficial to reducing the dosage of pesticides, reducing environmental pollution caused by pesticides, and can provide support for the development of new pesticides.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and in particular relates to a high-activity fungicide for preventing and controlling field diseases. Background Art

[0002] Rice sheath blight is a fungal disease caused by Rhizoctonia solani and is one of the most important rice diseases in the world. Rice sheath blight can occur throughout the entire growth period of rice, generally from the tillering stage to the heading stage, the disease is most serious, harming the leaf sheaths and leaves, and in severe cases, it can also harm the panicle and penetrate into the stems. The disease leads to a decrease in rice fruit setting rate and 1000-grain weight, seriously affecting rice yield.

[0003] For the prevention and control of rice sheath blight, commonly used pesticides in agricultural production include jinggangmycin, triadimefon and thiamethoxam, but the long-term use of a single pesticide to prevent and control the disease greatly increases the risk of pathogen resistance, resulting in a series of problems such as declining prevention effectiveness year by year, increased pathogen resistance and ecological environmental pollution.

[0004] Mixing pesticides is one of the effective measures to delay the development of pesticide resistance in agricultural pests. Compounding different pesticides can delay the development of pesticide resistance in pests, improve the control effect, reduce the amount of pesticides used, and thus reduce the pollution of pesticides to the environment.

[0005] CN201610138008.3 discloses a method for preparing a pesticide fungicide containing parthenolide and its use, and specifically discloses that parthenolide has good efficacy against a variety of pathogens such as rice sheath blight, rapeseed sclerotinia, wheat sheath blight, corn leaf blight, rice blast, rice bacterial leaf blight and rice bacterial leaf streak, among which the EC fungicide against rice sheath blight is 50 It is 36.83mg / L.

[0006] At present, there are no reports on the combination of pyraclostrobin, enoxastrobin, pyraclostrobin or thiophanate-methyl and parthenolide. Summary of the invention

[0007] The purpose of the present invention is to provide a highly active fungicide for preventing and controlling field diseases, so as to solve the problems of reduced control effect, increased drug resistance and ecological environment pollution caused by long-term use of a single agent.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A highly active fungicide for preventing and controlling field diseases, wherein the active ingredients are prepared by compounding pyraclostrobin, enoxastrobin, oxazolidinone or thiophanate-methyl and parthenolide, and the mass ratio of the compounding is 1-200:200-1.

[0010] Preferably, the mass ratio of pyraclostrobin to parthenolide is 1:35 - 1.

[0011] Preferably, the mass ratio of enestroburin to parthenolide is 1 - 5:20 - 1.

[0012] Preferably, the mass ratio of zoxamide to parthenolide is 1 - 30:10 - 1.

[0013] Preferably, the mass ratio of thifluzamide to parthenolide is 1 - 10:45 - 1.

[0014] Preferably, the rice disease is sheath blight of rice.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] When the active ingredients pyraclostrobin, enestroburin, zoxamide or thifluzamide and parthenolide in the pesticide composition of the present invention are compounded, the co-toxicity coefficient is greater than 120 within a certain mass ratio range, showing a synergistic effect. Based on this, the pesticide composition of the present invention can effectively control sheath blight of rice, and compared with a single agent, can improve the control effect on sheath blight of rice, is beneficial to reducing the dosage of pesticides, reducing environmental pollution by pesticides, and can provide support for the development of new pesticides. Specific Embodiments

[0017] According to the following embodiments, the present invention can be better understood. However, those skilled in the art can easily understand that the content described in the embodiments is only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0018] Embodiment : Screening of Agents for Controlling Sheath Blight of Rice

[0019] 1. Test strains: Rhizoctonia solani, collected from diseased rice plants in the rice fields in the suburbs of Zhengzhou, Henan, isolated and purified in the laboratory, and stored on PDA medium. (PDA medium formula: 200 g of peeled potatoes, 20 g of sucrose, 18 g of agar, 1 L of water, natural pH)

[0020] 2. Test agents: 98% pyraclostrobin (Jiamusi Heilong Pesticide Co., Ltd.), 90% enestroburin (Shenyang Kechuang Chemical Co., Ltd.), 99% zoxamide (Tianjin Aladdin Technology Co., Ltd.), 96% thifluzamide (Zhejiang Tianfeng Bioscience Co., Ltd.), 98% parthenolide (Shanghai Aladdin Biochemical Technology Co., Ltd.).

[0021] Dissolve the test agent in dimethyl sulfoxide solvent, and then dilute it with 0.1% Tween-80 aqueous solution to prepare a single-agent stock solution. Set multiple groups of ratios, and set 5 mass concentration gradients for each single agent and the mixed agent of the ratio according to the geometric ratio method.

[0022] 3. Test method (refer to "Guidelines for Indoor Biologial Assays of Pesticides - Fungicides - Part 2: Petri Dish Method for Inhibiting the Mycelial Growth of Pathogenic Fungi")

[0023] Add 9 mL of pre-melted PDA medium into a sterile conical flask. Quantitatively pipette 1.5 mL of the liquid medicine from low concentration to high concentration in turn, and add them into the above conical flask respectively. After shaking well, pour an equal amount into 3 petri dishes with a diameter of 9 cm to make drug-containing plates with corresponding concentrations; and set a treatment containing only 0.1% Tween-80 aqueous solution as a blank control, and set 3 replicates for each treatment.

[0024] Use a punch with a diameter of 5 mm to cut out a mycelial disc at the edge of the test strain colony, and inoculate it in the center of the drug-containing plate and the blank control plate. After covering the petri dish lid, place it in an incubator at a constant temperature of 25°C. After 48 h, measure the colony growth diameter by the cross method, and calculate the inhibition rate of mycelial growth for different treatments.

[0025]

[0026] 4. Data analysis: Use DPS software for data statistical analysis. Perform linear regression with the logarithm value of the agent concentration as x and the probit value of the corresponding mycelial growth inhibition rate as y to obtain the virulence regression equation and the virulence EC 50 value of the agent against the target pathogen, and calculate the co-toxicity coefficient (CTC) according to the Sun Yunpei method.

[0027] Actual toxicity index (ATI) = (EC50 of standard agent / EC50 of test agent) × 100;

[0028] Theoretical toxicity index (TTI) = toxicity index of agent A × percentage content of A in the mixture + toxicity index of agent B × percentage content of B in the mixture;

[0029] Co-toxicity coefficient (CTC) = [actual toxicity index (ATI) of the mixture / theoretical toxicity index (TTI) of the mixture] × 100.

[0030] 5. Test results

[0031] Evaluate the synergistic effect of the agent according to the calculated co-toxicity coefficient (CTC). CTC ≤ 80 indicates antagonistic effect, 80 < CTC < 120 indicates additive effect, and CTC ≥ 120 indicates synergistic effect. The results are shown in Table 1-4.

[0032] Table 1 Toxicity determination results of the compound of pyraclostrobin and parthenolide against Rhizoctonia solani

[0033]

[0034] As can be seen from Table 1, in the mass ratio range of 1:35 - 1, the co-toxicity coefficient of the compound of pyraclostrobin and parthenolide against Rhizoctonia solani is greater than 120, showing a synergistic effect.

[0035] Table 2 Toxicity determination results of the compound of enostroburin and parthenolide against Rhizoctonia solani

[0036]

[0037] As can be seen from Table 2, in the mass ratio range of 1 - 5:20 - 1, the co-toxicity coefficient of the compound of enostroburin and parthenolide against Rhizoctonia solani is greater than 120, showing a synergistic effect.

[0038] Table 3 Toxicity determination results of the compound of zoxamide and parthenolide against Rhizoctonia solani

[0039]

[0040] As can be seen from Table 3, in the mass ratio range of 1 - 30:10 - 1, the co-toxicity coefficient of the compound of zoxamide and parthenolide against Rhizoctonia solani is greater than 120, showing a synergistic effect.

[0041] Table 4 Toxicity determination results of the compound of thifluzamide and parthenolide against Rhizoctonia solani

[0042]

[0043] As can be seen from Table 4, in the mass ratio range of 1 - 10:45 - 1, the co-toxicity coefficient of the compound of thifluzamide and parthenolide against Rhizoctonia solani is greater than 120, showing a synergistic effect.

[0044] In summary, when pyraclostrobin, enostroburin, zoxamide or thifluzamide is compounded with parthenolide, the co-toxicity coefficient is greater than 120 within a certain mass ratio range, showing a synergistic effect. Based on this, the pesticide composition of the present invention can effectively control sheath blight of rice, and compared with a single agent, it can improve the control effect on sheath blight of rice, is beneficial to reducing the dosage of pesticides, reducing environmental pollution by pesticides, and can provide support for the development of new pesticides.

[0045] The above description is only a preferred embodiment of the present invention. For those skilled in the art, without departing from the raw materials of the present invention, appropriate improvements can be made, and these improvements are also within the protection scope of the present invention.

Claims

1. A highly active fungicide for preventing and controlling field diseases, characterized in that, Its active ingredients are composed of thifluzamide and parthenolide, and the mass ratio of thifluzamide to parthenolide is 1-10:45-1.

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