A fungicide composition for preventing and treating gummy stem blight of melon

Abstract

The present application belongs to the technical field of pesticides, and particularly relates to a fungicide composition for preventing and treating vine gummy stem blight. The fungicide composition for preventing and treating vine gummy stem blight is prepared by compounding thymol with monensin sodium or physcion methyl ether as effective components. The fungicide composition of the present application has different fungicidal mechanisms of thymol, monensin sodium and physcion methyl ether, and the combination of the three components can delay the accumulation and development of pathogenic fungi resistance, and effectively overcome the problems existing in the prevention and treatment of vine gummy stem blight by using single-component pesticides. In addition, the effective components of the fungicide composition of the present application have a synergistic effect on vine gummy stem blight, can improve the prevention and treatment effect on vine gummy stem blight, help to reduce the application dose of the pesticide, and effectively overcome the problems of pesticide residue exceeding the standard and environmental pollution. Furthermore, thymol, monensin sodium and physcion methyl ether in the fungicide composition of the present application are environmentally friendly and green.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically relating to a fungicide composition for controlling cucurbit vine blight. Background Technology

[0002] Cucurbit vine blight ( Stagonosporopsis cucurbitacearum Diseases can damage the leaves, stems, and fruits of cucurbits, leading to reduced yields and impacting both quantity and quality, severely hindering the healthy development of the cucurbit industry. Chemical agents play a crucial role in the control of diseases in cucurbits and other crops due to their advantages such as rapid effectiveness, precise targeting, and ease of application. However, they also have certain shortcomings. For example, long-term use of single-component agents can easily lead to the rapid development and accumulation of pesticide resistance, reducing their control efficacy. Furthermore, the excessive use of chemical agents can cause problems such as excessive pesticide residues and environmental pollution.

[0003] Thymol, also known as thymol or carvacrol, is an isomer of carvacrol and is currently widely used in fragrance production, as a preservative, medicinal fungicide, insect repellent, and antioxidant. Existing technologies also disclose the control effects of thymol on fungal diseases of crops. For example, patent CN116267945B discloses that the combination of osthol and thymol has a synergistic effect on *Trichoderma solani*, the causal agent of cucurbitacin blight, thus improving the control effect against this disease. Furthermore, patent CN116195591B discloses that the combination of thymol with prochloraz or fluoxetine has a synergistic effect on *Trichoderma solani*, thus improving the control effect against this disease.

[0004] However, there are currently no reports on the use of thymol in combination with sodium monensin or emodin methyl ether to control cucurbit vine blight.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a fungicide composition for controlling cucurbit vine blight, in order to solve the problems that long-term use of single-component agents can easily lead to the rapid development and accumulation of target resistance, resulting in reduced control efficacy. At the same time, the large-scale use of chemical agents can also cause excessive pesticide residues and environmental pollution.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A fungicide composition for controlling cucurbit vine blight, the active ingredient of which is a compound of thymol and monensin sodium or rhein methyl ether.

[0008] Furthermore, the mass ratio of thymol to monensin sodium is 1-9:18-1.

[0009] Furthermore, the mass ratio of thymol to emodin methyl ether is 1-15:1.

[0010] Compared with the prior art, the present invention has the following beneficial effects: (1) The fungicidal mechanisms of thymol and monensin sodium or rhein methyl ether in the fungicide composition of the present invention are different. Combining them helps to delay the accumulation and development of drug resistance in pathogens, and thus can effectively overcome the problems existing when using single-component agents to control cucurbit vine blight.

[0011] (2) When thymol is combined with sodium monensin or emodin methyl ether in the fungicide composition of the present invention, it has a synergistic effect on the cucurbit blight pathogen, which can improve the control effect of cucurbit blight, help reduce the dosage of the agent, and thus effectively overcome the problems of excessive pesticide residues and environmental pollution.

[0012] (3) The thymol, monensin sodium and rhein methyl ether in the bactericide composition of the present invention are environmentally friendly and green. Detailed Implementation

[0013] The technical solution of this invention patent will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0014] Example: Screening of control agents 1. Test strains Cucurbit wilt pathogen ( Stagonosporopsis cucurbitacearum ), isolate diseased plant samples from infected plants and preserve them on PDA medium.

[0015] 2. Test reagents 98% thymol technical grade, 95% monensin sodium technical grade, 98% emodin methyl ether technical grade The test reagent was dissolved in dimethyl sulfoxide and then diluted with 0.1% Tween-80 aqueous solution to prepare a high-concentration single-agent stock solution. Multiple formulations were set up, and each single-agent stock solution and formulation mixture was then diluted with 0.1% Tween-80 aqueous solution to prepare 5 mass concentration gradients.

[0016] 3. Test Methods The mycelial growth rate method was used.

[0017] The pre-melted PDA medium and drug solution were mixed evenly at a volume ratio of 9:1 and poured into 9 cm diameter petri dishes, 10 mL per dish. After cooling, the plates containing the drug were formed. A blank control without the drug was set up. Each drug concentration treatment was set up in 3 replicates, and each 3 plates constituted 1 replicate.

[0018] The tested strain of *Fusarium wilt*, the causal agent of cucurbitaceous plants, was inoculated onto PDA medium and cultured at 28°C for 7 days. Afterward, 7mm diameter mycelial discs were cut from the edge of the colonies using a punch and inoculated into the center of both the treated and blank control plates, one disc per plate. The plates were then covered and incubated at 25°C. When the diameter of the blank control colonies reached approximately 7cm, the colony diameter was measured using the cross-sectional method, and the inhibition rate of mycelial growth by different treatments was calculated.

[0019]

[0020] 4. Data Analysis Linear regression was performed with the logarithm of the fungicide concentration as x and the corresponding probability of mycelial growth inhibition as y to derive the virulence regression equation and the EC50 of the fungicide against the target pathogen. 50 The cotoxicity coefficient (CTC) was calculated using the Sun Yunpei method.

[0021]

[0022] In the above formula: ATI --The measured toxicity index of the mixture; S --EC of standard reagents 50 The unit is mg / L; M --EC mixture 50 The unit is mg / L.

[0023]

[0024] In the above formula: TTI --Theoretical toxicological index of the mixture; TI A --Toxicity index of drug A; P A --Percentage content of drug A in the mixture, expressed as percentage (%). TI B --Toxicity index of drug B; P B --The percentage content of drug B in the mixture, expressed as a percentage (%).

[0025]

[0026] In the above formula: CTC --Cotoxicity coefficient; ATI--Measured toxicity index of the mixture; TTI --Theoretical toxicity index of mixed formulations.

[0027] 5. Measurement Results The synergistic effect of the drug was evaluated based on the 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 1-2.

[0028] Table 1. Indoor bioactivity assay of thymol and monensin sodium combination against *Fusarium wilt*, the causal agent of cucurbitaceous plant vine blight. Drug Name and Proportion <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC thymol 97.3686 100.0000 -- -- Monensin sodium 19.4752 499.9620 -- -- Thymol 1: Monensin Sodium 18 16.9131 575.6993 478.9114 120.2100 Thymol 1: Monensin Sodium 12 14.5625 668.6256 469.1957 142.5046 Thymol 1: Monensin Sodium 9 12.2478 794.9885 459.9658 172.8364 Thymol 1: Monensin Sodium 3 19.7326 493.4403 399.9715 123.3689 Thymol 1: Monensin Sodium 1 24.2510 401.5034 299.9810 133.8430 Thymol 3: Monensin Sodium 1 39.1794 248.5199 199.9905 124.2658 Thymol 9: Monensin Sodium 1 46.9105 207.5625 139.9962 148.2629 Table 1 shows that thymol and monensin sodium, within a mass ratio of 1-9:18-1, have a significant effect on inhibiting the growth of *Fusarium wilt*, the pathogen of cucurbita. Stagonosporopsis cucurbitacearum The co-toxicity coefficients of mycelial growth were all greater than 120, indicating that the combination of thymol and imazalil showed a synergistic effect on the biological activity of cucurbit vine blight.

[0029] Table 2. Indoor bioactivity assay of thymol and emodin methyl ether combination against *Fusarium wilt*, the causal agent of cucurbitaceous plant vine blight. Drug Name and Proportion <![CDATA[EC 50 (mg / L)]]> ATI TTI CTC thymol 97.8436 100.0000 -- -- rhein methyl ether 12.8013 760.6149 -- -- Thymol 1: Emodin methyl ether 15 9.4585 1029.4296 719.3265 143.1102 Thymol 1: Emodin methyl ether 10 8.1384 1196.4096 700.5590 170.7793 Thymol 1: Emodin methyl ether 5 11.7581 828.0981 650.5124 127.2993 Thymol 1: Emodin methyl ether 1 14.3032 680.7470 430.3075 158.2001 Table 2 shows that thymol and emodin methyl ether, within a mass ratio of 1-15:1, have an inhibitory effect on the scab pathogen of cucurbitaceous plants (…). Stagonosporopsis cucurbitacearum The co-toxicity coefficients of mycelial growth were all greater than 120, indicating that the combination of thymol and imazalil showed a synergistic effect on the biological activity of cucurbit vine blight.

[0030] In summary, when thymol is combined with sodium monensin or emodin methyl ether in the fungicide composition of this invention, it has a synergistic effect on the cucurbit blight pathogen, which can improve the control effect on cucurbit blight, help reduce the dosage of the agent, and thus effectively overcome the problems of excessive pesticide residues and environmental pollution.

[0031] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A fungicide composition for controlling cucurbit vine blight, characterized in that, Its active ingredient is a compound of thymol and monensin sodium or emodin methyl ether.

2. The fungicide composition for controlling cucurbit vine blight according to claim 1, characterized in that, The mass ratio of thymol to monensin sodium is 1-9:18-1.

3. The fungicide composition for controlling cucurbit vine blight according to claim 1, characterized in that, The mass ratio of thymol to emodin methyl ether is 1-15:1.