Agricultural bactericidal composition containing WML-01 and fludioxonil as well as preparation and application thereof

Abstract

The invention discloses a bactericidal composition containing WML-01 and fludioxonil, the active ingredients of the bactericidal composition comprise the WML-01 and the fludioxonil, and the mass ratio of the WML-01 to the fludioxonil is (10: 1)-(1: 10). The bactericidal composition can be used for preventing and treating rice bakanae disease, wheat stem rot, wheat scab, soybean root rot, rice blast, pepper anthracnose and sclerotinia rot of colza, can effectively solve the problems of few disease prevention and treatment agents, unstable prevention effect, high prevention and treatment cost and drug resistance in current production, and has a wide market application prospect.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and in particular to an agricultural fungicide composition containing WML-01 and fludioxonil, its formulation and application. Background Technology

[0002] Rice bakanae disease, also known as excessive growth disease, is a significant disease affecting rice production. The main pathogen is *Fusarium oxysporum* (Fusarium oxysporum). Fusarium fujikuroi Infected seeds and diseased plant debris in the field are the main primary sources of infection for rice bakanae disease. Infected grains often fail to germinate or emerge after sowing. Typically, infected seedlings are thinner and taller than healthy seedlings, with slender leaf sheaths, pale yellow leaves, and poor root development; some seedlings die before transplanting. After transplanting, the mycelium can spread throughout the entire plant under suitable conditions, stimulating excessive vegetative growth. During flowering, the pathogen spreads to the flowers, invading the glumes and endosperm, causing shriveled or deformed grains. If the pathogen invades late, although the grains may not show symptoms, the mycelium has already penetrated internally, making the seeds infected and affecting the planting of subsequent rice crops, causing significant damage. Chemical control remains the primary method for controlling rice bakanae disease. Currently, fungicides registered for the control of rice bakanae disease on the market include carbendazim, prochloraz, difenoconazole, and fludioxonil. However, the long-term, large-scale, and frequent use of chemical agents has led to pathogens gradually developing resistance to different fungicides, resulting in a significant reduction in the effectiveness of the agents. Increasing the amount of pesticides used will lead to problems such as pesticide residues, seed safety, and environmental pollution.

[0003] Wheat stem base rot, commonly known as "crown rot" or "dryland foot disease," is caused by Fusarium graminearum (…). Fusarium pseudograsses Fusarium graminearum ( ), Fusarium gramineae This is a global wheat stem base rot caused by various Fusarium fungi, including [list of fungi]. Early symptoms of wheat stem base rot include browning and rotting of young roots or coleoptiles, leading to seedling death in severe cases. The disease then spreads to the first and second stem nodes, causing the affected areas to turn dark brown or rot. The leaf sheaths at the stem base wither, and the stem turns brown and necrotic. Later, the browning at the stem base hinders the transport of water from the roots to the ear, resulting in a completely white ear. After the ear forms a "white ear," the wheat grains cannot continue to develop, significantly impacting the grain filling rate and yield. Currently, only eight pesticide products are registered for the control of this disease, including difenoconazole, tebuconazole, fludioxonil, prothioconazole, triflupyridine, and thiamethoxam. There is an urgent need for new pesticides to control this disease.

[0004] Fusarium head blight, commonly known as "wheat rot," is a global wheat disease caused by various Fusarium fungi, including Fusarium graminearum. F. graminearumFusarium head blight (FHB) is a dominant pathogen in many wheat-producing areas. It causes seedling blight, stem rot, and ear rot; in epidemic years, the disease incidence rate often exceeds 50%, resulting not only in a significant reduction in yield and deterioration in quality, but also in the presence of toxins in the diseased grains, which can cause poisoning in humans and animals. Fungicides used to control FHB in production mainly include benzimidazole fungicides, triazole fungicides, methoxyacrylate fungicides, and methoxyacrylate fungicides. The long-term and extensive use of chemical fungicides has led to increasingly prominent resistance issues to the FHB fungus.

[0005] Root rot is a common disease in plant production. The pathogen primarily damages the plant roots, causing poor plant growth, seed rot, root decay, stunting, yellowing flowers, and in severe cases, complete plant death, leading to significant yield losses. Soybean root rot is a major root disease in soybean production, with pathogens including Fusarium, Rhizoctonia solani, and Pythium. In the seedling stage, root rot affects seedling growth and can even cause seedling death, reducing the number of seedlings remaining in the field. In mature plants, root damage affects the growth and number of root nodules, resulting in poor above-ground growth, stunting, and reduced pod number and grain weight, thus lowering yield. Currently, fungicides registered for the control of soybean root rot include difenoconazole, prochloraz, fludioxonil, carbendazim, and thiram.

[0006] Rice blast, also known as rice fever, fire blast, or knocking blast, is one of the important diseases of rice. The pathogen is *Pyrrosia oryzae* (rice blast). Rice blast Rice blast (Cav.) mainly includes seedling blast, leaf blast, node blast, neck blast, and grain blast, with neck blast and node blast being the most severe, causing yield losses of 10%-30% in mild cases and 40%-50% or even total crop failure in severe cases. Fungicides used in production to control rice blast mainly include tricyclazole, carbendazim, isoprothiolane, prochloraz, pyraclostrobin, and jinggangmycin. The long-term and extensive use of chemical fungicides has led to increasingly prominent issues of herbicide resistance in rice blast.

[0007] Anthracnose is a common plant disease that primarily affects leaves, fruits, and branches, causing sunken lesions. These lesions are often covered with numerous small black dots (conidiophores), severely impacting the yield and quality of plant products. The pathogens causing anthracnose are mainly fungi of the genus *Anthracnose* (*Hylocereus*). Colletotrichum spp.) fungi, including collodion fungus ( Colletotrichum gloeosporioides Anthracnose is a representative species that can cause anthracnose in plants such as citrus, mango, pomegranate, grape, strawberry, pepper, tomato, ginger, onion, rubber, corn, sugarcane, and various flowers. Currently, the main pesticides for controlling anthracnose include fludioxonil, methoxyacrylates, and benzimidazoles. While there are many pesticide products available, the variety is relatively concentrated; products containing difenoconazole and pyraclostrobin account for over 25% of the total. This long-term, concentrated use of chemical pesticides has led to increasingly prominent problems with anthracnose resistance.

[0008] Sclerotinia stem rot is the most threatening disease to rapeseed production, and the pathogen is Sclerotinia stem rot (Sclerotinia stem rot). Sclerotinia sclerotia This disease can infect the stems, leaves, flowers, and pods of rapeseed, with the stems being the most severely affected. After infection, water-soaked, light brown lesions appear on the rapeseed stems. Later, the center of the lesions turns white, while the edges turn brown, with a clear boundary between diseased and healthy tissue. In humid conditions, white, cottony mycelium grows on the lesions, eventually leading to stem rot, breakage, and the death of the entire plant, resulting in total crop failure. Currently, there is a severe shortage of pesticides for controlling rapeseed sclerotinia rot. Most pesticides used are limited to carbendazim, iprodione, and fludioxonil, but resistance to carbendazim has become serious. There is an urgent need for new pesticide varieties to control this disease, replace carbendazim, and control the development of resistance.

[0009] Fludioxonil is a pyrrole fungicide. Its mechanism of action involves interfering with and disrupting the bio-oxidation and biosynthesis processes of pathogens, thereby inhibiting nucleic acid and protein synthesis and leading to pathogen death. It has excellent control effects on various crops, including gray mold, sclerotinia rot, damping-off, root rot, wilt, and stem blight. Fludioxonil lacks systemic activity but exhibits significant protective activity and high safety, making it widely used for seed treatment in crops. Currently, there are 305 pesticide products containing fludioxonil registered in China. Among these, 111 are used to control plant root rot, 72 to control rice bakanae disease, and 2 to control wheat scab. Combining fludioxonil with other systemic fungicides for plant disease control is a future trend.

[0010] Currently, there are few pesticides available for controlling rice bakanae disease, wheat stem rot, wheat scab, plant root rot, rice blast, plant anthracnose, and rapeseed sclerotinia stem rot. Furthermore, the long-term and extensive use of selective pesticides with single mechanisms of action has led to varying degrees of pesticide resistance in pathogens. Developing fungicides with novel mechanisms of action and introducing them to the market, and through scientific compounding, rationally combining these novel fungicides with broad-spectrum, highly effective, and protective fludioxonil, can reduce pesticide dosage, improve efficacy, and delay the development of resistance. This is of great significance for controlling disease occurrence and extending the life cycle of pesticides. Summary of the Invention

[0011] The purpose of this invention is to provide an agricultural fungicide composition containing WML-01 and fludioxonil, its formulation, and its application, in order to solve the technical problems that currently exist, such as the limited variety of fungicides for the control of rice seedling blight, wheat stem base rot, wheat scab, plant root rot, rice blast, plant anthracnose, and rapeseed sclerotinia stem rot, and the fact that pathogens have developed varying degrees of resistance due to the long-term and large-scale use of selective fungicides with single mechanisms of action.

[0012] To achieve the objectives of this invention, a first aspect of this invention is to provide an agricultural fungicide composition, wherein the active ingredients of the agricultural fungicide composition include WML-01 and fludioxonil, the mass ratio of WML-01 to fludioxonil is 10:1 to 1:10, and WML-01 is a butenolactone compound containing a thiazolidinone structure, with the structural formula shown in Formula I: .

[0013] In one optional embodiment, the mass ratio of WML-01 to fludioxonil is 10:1 to 1:1.

[0014] In one optional embodiment, the mass ratio of WML-01 to fludioxonil is 3:1 to 1:10.

[0015] A second aspect of the present invention is to provide a bactericide formulation comprising the agricultural bactericide composition.

[0016] In one optional embodiment, the bactericidal formulation is a seed coating agent, suspension, emulsion, microemulsion, emulsifiable concentrate, microcapsule suspension, nanoformulation, granules, wettable powder, or water-dispersible granules.

[0017] In one optional embodiment, the bactericide formulation further includes an adjuvant or carrier that assists the agricultural bactericide composition, wherein the adjuvant is xanthan gum, wetting agent, dispersant, defoamer, antifreeze agent, or warning color.

[0018] In one optional embodiment, the wetting agent is nonylphenol polyoxyethylene ether NP-10, alkylphenol polyoxyethylene ether OP-10, or alkyl naphthalene sulfonate EFW; the dispersant is sodium salt D-425 of alkyl naphthalene sulfonate condensate or sulfonate D-450 of alkyl naphthalene sulfonate condensate; the defoamer is n-octanol or organosilicon SAG1522; the antifreeze agent is ethylene glycol; and the warning color is basic rose essence, golden red, or sun-resistant peach red.

[0019] A third aspect of the present invention is to provide the application of a bactericidal composition or bactericidal agent in the control of plant diseases, wherein the plant disease is rice bakanae disease (…). Fusarium fujikuroi ), wheat stem rot ( Fusarium pseudograsses ), wheat scab ( Fusarium gramineae ), soybean root rot ( Fusarium spp.), rice blast ( Rice blast Anthracnose of peppers ( Colletotrichum spp.) or rapeseed sclerotinia disease ( Sclerotinia sclerotiorum ) one or more.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The agricultural fungicide composition provided by this invention, with WML-01 and fludioxonil as active ingredients, has a synergistic effect on the control of rice seedling blight, wheat stem base rot, wheat scab, plant root rot, rice blast, plant anthracnose, and rapeseed sclerotinia rot. It can effectively improve the control effect of diseases, reduce the amount of pesticides used, delay the occurrence of pesticide resistance, and increase crop yield. It is safe, effective, and economical, and has broad market application prospects. Detailed Implementation

[0021] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available products.

[0022] Agricultural fungicidal compositions and their formulations can be applied in various ways, and this invention does not impose any particular limitation. One or a combination of various application methods can be used, such as seed coating, seed soaking, spraying, root drenching, broadcasting, hole application, and furrow application. Depending on crop cultivation, formulation type, and target pests, seed coating, seed dressing, and seed soaking are preferred methods for this fungicidal agricultural composition.

[0023] Example 1: In vitro antibacterial activity of WML-01 and fludioxonil against *Bacillus bakanae*, *Bacillus thuringiensis*, *Fusarium graminearum*, *Fusarium graminearum*, *Bacillus oryzae*, *Sclerotinia sclerotiorum*, *Sclerotinia sclerotiorum*, and *Anthracnose* of peppers. 1. Test materials 1.1 Test strains Rice seedling blight pathogen ( F. fujikuroi (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0024] Soybean root rot pathogen ( F. oxysporum (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0025] Wheat stem rot fungus ( F. pseudograminearum (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0026] Fusarium head blight of wheat ( F. grasses (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0027] Rice blast fungus ( P. oryzae (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0028] Sclerotinia sclerotiorum (Sclerotinia sclerotiorum) S. sclerotiorum (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0029] Anthracnose of pepper ( C. gloeosporioides (Provided by the College of Plant Protection, China Agricultural University), identified using conventional methods.

[0030] 1.2 Test reagents WML-01 (99% technical grade), provided by the College of Science, China Agricultural University. This compound and its preparation method are disclosed in patent publication number CN 118724887 A, compound number 3-1.

[0031] Its structural formula is shown in Formula I:

[0032] Fludioxonil (98% technical grade), a product of Shangyu Yingtai Fine Chemical Co., Ltd.

[0033] The above-mentioned pesticide technical materials were prepared into 10% concentrations using dimethyl sulfoxide as a solvent. 4 The stock solution of mg / L was stored in a refrigerator at 4°C for later use.

[0034] 1.3 Test Culture Medium Potato glucose agar (PDA): 200 g potato, 18 g glucose, 12 g agar powder, 1000 mL distilled water.

[0035] 2. Test Methods The experiment was conducted according to NY / T 1156.2-2006, "Guidelines for Indoor Bioassay Testing of Pesticides - Part 2: Tests for Inhibition of Mycelial Growth of Pathogenic Fungi," using the plate method. The main procedure for the plate method is as follows: Five concentration gradients were set between 10% and 90% for the inhibition rate of the pesticide against the target bacteria. Then, using a 6mm diameter punch, mycelial cakes were collected from the same circumference near the edge of the activated target bacteria colony (ensuring the same age of the tested pathogens in the same replicate). Under aseptic conditions, the mycelial cakes were inoculated onto the center of a series of drug-containing culture plates, with the mycelial side facing down. A plate without pesticide was used as a control. All plates were incubated in the dark. Each treatment was repeated three times. The colony diameter for each concentration treatment was recorded, and the mycelial growth inhibition rate was calculated. Then, the inhibition rate was converted into a probability value (Y), and the drug concentration was converted into a logarithmic value to base 10 (X). A regression line was plotted between X and Y to obtain the virulence regression curve equation Y=a+bX for each drug against the target bacteria, as well as the correlation coefficient r and the effective inhibition concentration EC. 50 .

[0036] The combined toxicity of compound preparations was expressed using Sun Yunpei's co-toxicity coefficient method: Theoretical toxicity index of compound preparations THIRTY =∑(Toxicity index of a certain drug × Percentage of the active ingredient of the drug in the mixture).

[0037]

[0038] CTC At ≥120, it has a synergistic effect; CTC ≤ 80 indicates antagonistic effect; < 80 indicates antagonistic effect. CTC When the value is less than 120, the effect is additive.

[0039] 3. Experimental Results Table 1. In vitro antibacterial activity of WML-01 and fludioxonil against *Bakanaeda jatropha*, the pathogen of rice seedling blight.

[0040] The above results indicate that the co-toxicity coefficients of WML-01 and fludioxonil against rice bakanae diseased fungus ranged from 84.21 to 169.37 within a compound ratio of 10:1 to 1:10 (w / w), demonstrating additive and synergistic effects. Specifically, when the mass ratio of WML-01 to fludioxonil was within the range of 10:1 to 1:1, the co-toxicity coefficients were all greater than 120, exhibiting a significant synergistic effect, reaching a maximum of 169.37.

[0041] Table 2. In vitro antibacterial activity of WML-01 and fludioxonil against *Hydrocotyle spp.*, the pathogen causing wheat stem rot.

[0042] The above results indicate that when WML-01 and fludioxonil are combined at a mass ratio of 10:1 to 1:10 (w / w), the co-toxicity coefficients against wheat stem rot pathogens, determined by the co-toxicity coefficient method, range from 88.65 to 133.61, demonstrating additive and synergistic effects. Specifically, when the mass ratio of WML-01 to fludioxonil is within the range of 3:1 to 1:10, the co-toxicity coefficients are all greater than 120, exhibiting a synergistic effect.

[0043] Table 3. In vitro antibacterial activity of WML-01 and fludioxonil against Fusarium graminearum, the causal agent of wheat blight.

[0044] The above results indicate that when WML-01 and fludioxonil are combined at a mass ratio of 10:1 to 1:10 (w / w), the co-toxicity coefficients against Fusarium graminearum, the causal agent of wheat scab, range from 98.4 to 182.13, as determined by the co-toxicity coefficient method. This shows additive and synergistic effects. When the mass ratio of WML-01 to fludioxonil is in the range of 3:1 to 1:10, the co-toxicity coefficients are all greater than 120, demonstrating a synergistic effect. The synergistic effect is significant, reaching a maximum of 182.13.

[0045] Table 4. In vitro antibacterial activity of WML-01 and fludioxonil against soybean root rot pathogen.

[0046] The above results indicate that when WML-01 and fludioxonil are combined at a mass ratio of 10:1 to 1:10 (w / w), the co-toxicity coefficients against soybean root rot pathogens, determined by the co-toxicity coefficient method, range from 93.27 to 144.23, showing additive and synergistic effects. Among them, when the mass ratio of WML-01 to fludioxonil is in the range of 1:1 to 1:10, the co-toxicity coefficients are all greater than 120, showing a synergistic effect, and the synergistic effect is significant, reaching a maximum of 144.23.

[0047] Table 5. In vitro antibacterial activity of WML-01 and fludioxonil against rice blast pathogen.

[0048] The above results indicate that when WML-01 and fludioxonil are combined at a mass ratio of 10:1 to 1:10 (w / w), the co-toxicity coefficients against rice blast fungus, determined by the co-toxicity coefficient method, range from 93.79 to 132.65, showing additive and synergistic effects. Among them, when the mass ratio of WML-01 to fludioxonil is in the range of 3:1 to 1:1, the co-toxicity coefficients are all greater than 120, showing a synergistic effect.

[0049] Table 6. In vitro antibacterial activity of WML-01 and fludioxonil against Sclerotinia sclerotiorum var. sclerotiorum in rapeseed.

[0050] The above results indicate that when WML-01 and fludioxonil are combined at a mass ratio of 10:1 to 1:10 (w / w), the co-toxicity coefficients against Sclerotinia sclerotinia, the causal agent of rapeseed, range from 89.47 to 150.43, as determined by the co-toxicity coefficient method. This shows additive and synergistic effects. When the mass ratio of WML-01 to fludioxonil is in the range of 2:1 to 1:10, the co-toxicity coefficients are all greater than 120, showing a significant synergistic effect, which can reach a maximum of 150.43.

[0051] Table 7. In vitro antibacterial activity of WML-01 and fludioxonil against *Anthracnose causal agent*.

[0052] The above results indicate that when WML-01 and fludioxonil are combined at a mass ratio of 10:1 to 1:10 (w / w), the co-toxicity coefficients against *Anthracnose causal agent* of pepper are determined by the co-toxicity coefficient method, ranging from 80.24 to 191.82, showing additive and synergistic effects. Among them, when the mass ratio of WML-01 to fludioxonil is in the range of 5:1 to 1:1, the co-toxicity coefficients are all greater than 120, showing a synergistic effect, and the synergistic effect is significant, reaching a maximum of 191.82.

[0053] Example 2: Field control efficacy of WML-01 and fludioxonil combined with wheat scab. 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 30% fludioxonil suspension concentrate, product of Jiangxi Zhengbang Crop Protection Co., Ltd.

[0054] 1.2 Overview of the test site The experiment was conducted in Fengtai County, Anhui Province, in a clay loam soil with moderate fertility. The wheat variety was Huaiyumai No. 1, and the seed rate was 25 kg per mu.

[0055] 1.3 Experimental Design Table 8. Experimental protocols for seed treatment against wheat scab.

[0056] 1.4 Survey Methods and Calculations Five random sampling points were taken from each treatment area, with 100 ears of panicle at each point. The disease index and control effect were calculated based on the percentage of panicle dead area to the total panicle area.

[0057] Grading standards for Fusarium head blight: Grade 0, disease-free throughout the ear of grain; Grade 1: The area of ​​dead ears accounts for less than 1 / 4 of the total ear area; Grade 3, with withered ears covering 1 / 4 to 1 / 2 of the total ear area; Grade 5, withered ears covering 1 / 2 to 3 / 4 of the total ear area; Grade 7, with withered ears covering more than 3 / 4 of the total ear area; Methods for calculating drug efficacy: Disease index (%) = ∑(Number of diseased plants (ears) at each level × Representative value at each level) / (Total number of plants (ears) surveyed × Highest representative value) × 100 Control efficacy (%) = (Disease index after treatment in control area - Disease index after treatment in treatment area) / Disease index after treatment in control area × 100 2. Experimental Results Table 9. Control efficacy of pesticide treatments against wheat scab.

[0058] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0059] As shown in the table above, after two applications, the high-dose (200 ml) treatment of 10% WML-01·fludioxonil suspension (20 g active ingredient) achieved a control efficacy of 90.49% against wheat scab, which was significantly better than the single-dose treatment of fludioxonil (12 g active ingredient) and the single-dose treatment of WML-01 (20 g active ingredient). The low-dose (100 ml) treatment (10 g active ingredient) achieved a control efficacy of 85.41% against wheat scab, which was comparable to the single-dose treatment of WML-01 and better than the single-dose treatment of fludioxonil.

[0060] The above results indicate that the combination of WML-01 and fludioxonil, at a dosage similar to that of fludioxonil alone, exhibits excellent control efficacy against wheat scab, while requiring less field application compared to WML-01 alone.

[0061] Example 3: Field control efficacy of WML-01 and fludioxonil combined with soybean root rot 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 25g / L fludioxonil seed treatment suspension concentrate, produced by Beinong Haili (Zhuozhou) Seed Coating Agent Co., Ltd.

[0062] 1.2 Overview of the test site The experimental site was located in the Beian Modern Agricultural Demonstration Park. The soil type was black soil, with an organic matter content of 5.6% and a pH of 6.6. Sowing was carried out on May 21, 2024, using a 65cm ridge-three cultivation pattern, maintaining 320,000 plants per hectare. 48% soybean-specific fertilizer was applied at a rate of 320 kg per hectare (N:P:K = 15:23:10). Emergence occurred on June 1. Soil moisture was good. The previous crop was soybean. Irrigation relied on natural rainfall.

[0063] 1.3 Experimental Design Table 10 Experimental protocols for seed treatments against plant root rot

[0064] 1.4 Survey Methods and Calculations Soybean root rot survey Surveys were conducted twice, at 30 days and 60 days after soybean emergence. At least 30 soybean plants were randomly selected from each plot for investigation, and the total number of plants and the number of plants with diseases at each level were recorded. The incidence of root rot was investigated, and the effectiveness of control measures was calculated.

[0065] Disease classification: (area of ​​root lesions) Grade 0: Main root and fibrous roots are intact, with no disease spots and many root nodules; Grade 1: Scattered lesions on the main root, but not in clusters; lesions on the fibrous roots for several days. Grade 3: The main root shows numerous lesions, but the lesions cover less than 1 / 4 of the root area; the fibrous roots are slightly affected. Grade 5: The lesions on the main root cover an area of ​​1 / 4 to 1 / 2 of the root area. There are many fibrous roots affected, but they do not form large patches. Grade 7: The area of ​​lesions on the main root is between 1 / 2 and 1 / 4 of the root area, and the lesions on the fibrous roots are in patches, with some fibrous roots falling off; Level 9: The entire root system is surrounded by disease spots, the root is rotten, and there are almost no fibrous roots.

[0066] Methods for calculating drug efficacy: Disease index (%) = ∑(Number of diseased plants (ears) at each level × Representative value at each level) / (Total number of plants (ears) surveyed × Highest representative value) × 100 Control efficacy (%) = (Disease index after treatment in control area - Disease index after treatment in treatment area) / Disease index after treatment in control area × 100 2. Experimental Results Table 11. Control efficacy of chemical treatments against soybean root rot

[0067] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0068] As shown in the table above, the control efficacy of 200 ml of high-dose 10% WML-01·fludioxonil suspension (20 g active ingredient) and 100 ml of high-dose seed treatment (10 g active ingredient) against soybean root rot was 80.61% and 77.57%, respectively, which was significantly better than that of WML-01 single agent (20 g active ingredient) and fludioxonil single agent treatment (10 g active ingredient).

[0069] A survey conducted 60 days after emergence showed that seed treatments with 100 ml and 200 ml of 10% WML-01·fludioxonil suspension exhibited excellent control efficacy against soybean root rot, with efficacy rates of 86.01% and 91.02%, respectively, significantly superior to single treatments with WML-01 and fludioxonil.

[0070] The above results indicate that the combination of WML-01 and fludioxonil, at the same dosage as fludioxonil alone, exhibits excellent control efficacy against soybean root rot. Compared with the WML-01 single-agent treatment, the field application dosage is reduced while the control efficacy is improved.

[0071] Example 4: Field control efficacy of WML-01 and fludioxonil combined with wheat stem rot 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 25g / L fludioxonil seed treatment suspension concentrate, produced by Beinong Haili (Zhuozhou) Seed Coating Agent Co., Ltd.

[0072] 1.2 Overview of the test site The experiment was conducted in Feixiang District, Handan City, Hebei Province. The soil was clay loam with moderate fertility. The wheat variety was Woyu No. 3, and the seed rate was 20 kg per mu.

[0073] 1.3 Experimental Design Table 12 Experimental protocol for seed treatment against wheat stem rot

[0074] 1.4 Survey Methods and Calculations Stem base rot survey a) Survey on the efficacy of stem base rot control during the grain-filling stage Five random sampling points were taken from each treatment area, with 100 plants at each point. The number of diseased plants and the disease index were investigated, and the disease index and control effect were calculated.

[0075] Grading standards for stem base rot: Grade 0, the plant is not diseased; Grade 1, the stem in the ground is noticeably brown; Level 3, the first intersegment turns brown; Level 5, second interphalangeal joint turns brown; Level 7, browning symptoms appear in the third internode, but no white ears; Level 9: White ears or plant death due to disease.

[0076] Methods for calculating drug efficacy: Disease index (%) = ∑(Number of diseased plants (ears) at each level × Representative value at each level) / (Total number of plants (ears) surveyed × Highest representative value) × 100 Control efficacy (%) = (Disease index after treatment in control area - Disease index after treatment in treatment area) / Disease index after treatment in control area × 100 b) Survey of white ear rate during grain-filling period Five random sampling points were taken from each treatment area, with 100 plants at each point. The total number of ears and the number of white ears were investigated, and the control effect was calculated.

[0077] White ear rate (%) = Number of white ears / Total number of plants surveyed × 100 Control efficacy (%) = [White ear rate in control area - White ear rate in treated area] / White ear rate in control area × 100 2. Experimental Results Table 13. Control efficacy of pesticide treatments against wheat stem rot.

[0078] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0079] As shown in the table above, during the grain-filling stage, the high-dose (200 ml) seed dressing treatment with 10% WML-01·fludioxonil suspension (20 g active ingredient) achieved a control efficacy of 91.31% against wheat stem base rot, while the low-dose (100 ml) treatment (10 g active ingredient) achieved a control efficacy of 83.99%. Both were significantly superior to the single-agent seed dressing treatment with fludioxonil (10 g active ingredient) and the single-agent treatment with WML-01 (20 g active ingredient).

[0080] The results of the white ear rate survey showed that the high-dose (200 ml) treatment of 10% WML-01·fludioxonil suspension achieved a white ear control efficacy of 93.96%; the low-dose (100 ml) treatment achieved a white ear control efficacy of 87.77%. Both were significantly better than the single-agent treatments of WML-01 and fludioxonil.

[0081] The above results indicate that the combination of WML-01 and fludioxonil, at the same dosage as fludioxonil alone, exhibits excellent control efficacy against wheat stem rot. Compared with the single treatment of WML-01, the field application amount is reduced while the control efficacy is improved.

[0082] Example 5: Field control efficacy of WML-01 and fludioxonil combined with rice bakanae disease 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 25g / L fludioxonil seed treatment suspension concentrate, produced by Beinong Haili (Zhuozhou) Seed Coating Agent Co., Ltd.

[0083] 1.2 Overview of the test site The experiment was conducted in Zhaoyuan Village, Yaojiang Town, Zhuji City, Zhejiang Province. The soil was clay loam with moderate fertility. The rice variety was Zhongzao 39, and the seed rate was 5 kg per mu. Seedlings were raised and transplanted.

[0084] 1.3 Experimental Design Table 14 Experimental protocol for seed treatment against rice bakanae disease

[0085] 1.4 Survey Methods and Calculations Bakanae disease: Five random sampling points were taken from each plot in the seedbed, with each sampling point measuring 10cm*10cm. The sampling was repeated three times. The disease incidence rate was recorded, and the control efficacy was calculated.

[0086] Disease incidence rate (%) = (Number of diseased plants / Total number of plants surveyed) × 100% Control efficacy (%) = (Disease rate in the blank control area - Disease rate in the treatment area) / Disease rate in the blank control area × 100% 2. Experimental Results Table 15. Control efficacy of pesticide treatments against rice bakanae disease.

[0087] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0088] As shown in the table above, during the seedling stage, the high-dose seed treatment of 200 ml of 10% WML-01·fludioxonil suspension (20 g of active ingredient) achieved a control efficacy of 97.97% against rice bakanae disease; the seed treatment of 100 ml (10 g of active ingredient) achieved a control efficacy of 94.09% against rice bakanae disease, both of which were significantly better than the single treatment of fludioxonil (10 g of active ingredient) and the single treatment of WML-01 (20 g of active ingredient).

[0089] The above results indicate that the combination of WML-01 and fludioxonil, at the same dosage as fludioxonil alone, exhibits excellent control efficacy against rice bakanae disease. Compared with the WML-01 single-agent treatment, the field application dosage is reduced while the control efficacy is improved.

[0090] Example 6: Field control efficacy of WML-01 and fludioxonil combined with rice blast. 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 30% fludioxonil suspension concentrate, product of Jiangxi Zhengbang Crop Protection Co., Ltd.

[0091] 1.2 Overview of the test site The experiment was conducted in Chadi Township, Shanghang County, Longyan City, Fujian Province, using the rice variety Changliangyou 8.

[0092] 1.3 Experimental Design Table 16 Experimental protocols for pesticide treatments against rice blast disease

[0093] 1.4 Survey Methods and Calculations A five-point sampling method was used, with at least 20 panicles sampled at each point. Each plot consisted of 100 panicles, and the total number of panicles, the number of diseased panicles, and the disease severity were recorded. The disease index and control effectiveness were calculated.

[0094] The grading standards for rice neck blast are as follows: Level 0: No disease; Level 1: Less than 5% loss per ear (individual branches affected); Level 3: 6% to 20% loss per ear (about one-third of the branches and stalks are affected); Grade 5: 21% to 50% loss per ear (disease on the neck or main axis, grains half-empty); Level 7: 51%~70% loss per ear (neck disease, most ears are empty); Grade 9: 71% to 100% loss per ear (caused by disease at the neck of the ear, resulting in white ears).

[0095] Methods for calculating drug efficacy: Disease index (%) = ∑(Number of diseased plants (ears) at each level × Representative value at each level) / (Total number of plants (ears) surveyed × Highest representative value) × 100 Control efficacy (%) = (Disease index after treatment in control area - Disease index after treatment in treatment area) / Disease index after treatment in control area × 100 2. Experimental Results Table 17. Control efficacy of pesticide treatments against rice blast.

[0096] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0097] As shown in the table above, after two applications, the high-dose (200 ml) treatment (20 g active ingredient) and low-dose (100 ml) treatment (10 g active ingredient) of 10% WML-01·fludioxonil suspension showed control efficacy of 90.46% and 84.40% against rice blast, respectively, which were significantly better than the fludioxonil single-agent treatment (12 g active ingredient) and the WML-01 single-agent treatment (20 g active ingredient).

[0098] The above results indicate that the combination of WML-01 and fludioxonil exhibits excellent control efficacy against rice blast at a lower dosage than fludioxonil alone. Compared with the WML-01 single-agent treatment, the field application amount is significantly reduced while the control efficacy is improved.

[0099] Example 7: Field control efficacy of WML-01 and fludioxonil combined with rapeseed sclerotinia stem rot 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 30% fludioxonil suspension concentrate, product of Jiangxi Zhengbang Crop Protection Co., Ltd.

[0100] 1.2 Overview of the test site The experiment was conducted in Dafasi Town, Wuxue City, Huanggang City, Hubei Province, in a loamy soil.

[0101] The rapeseed variety Huayouza 62 was sown at a rate of 400g / mu.

[0102] 1.3 Experimental Design Table 18 Experimental Protocol for Chemical Treatment of Sclerotinia stem Cellar Disease in Rapeseed

[0103] 1.4 Survey Methods and Calculations A five-point sampling method was used, with at least 40 plants sampled at each point, and 200 plants surveyed per plot. The number of diseased plants and the disease severity were recorded for each plot. The disease index and control effect were calculated.

[0104] The grading criteria are as follows: Level 0: No disease; Grade 1: The affected area accounts for less than 5% of the surface area of ​​the main stem; Level 3: The affected area accounts for more than 5% but less than 15% of the main stem surface area; Level 5: The affected area accounts for more than 15% but less than 30% of the main stem surface area; Level 7: The affected area accounts for more than 30% but less than 50% of the main stem surface area; Level 9: The diseased area accounts for more than 50% of the surface area of ​​the main stem.

[0105] Methods for calculating drug efficacy: Disease index (%) = ∑(Number of diseased plants at each level × Representative value at each level) / (Total number of plants surveyed × Highest representative value) × 100 Control efficacy (%) = (Disease index after treatment in control area - Disease index after treatment in treatment area) / Disease index after treatment in control area × 100 2. Experimental Results Table 19. Control efficacy of chemical treatments against sclerotinia stem rot in rapeseed.

[0106] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0107] As shown in the table above, after two applications, the high-dose (150 ml) treatment of 10% WML-01·fludioxonil suspension (15 g active ingredient) achieved a control efficacy of 92.09% against Sclerotinia sclerotinia in rapeseed, significantly better than the fludioxonil single-agent treatment (12 g active ingredient) and the WML-01 single-agent treatment (20 g active ingredient). The low-dose (75 ml) treatment (7.5 g active ingredient) achieved a control efficacy of 85.20% against Sclerotinia sclerotinia in rapeseed, comparable to the fludioxonil single-agent treatment and better than the WML-01 single-agent treatment.

[0108] The above results indicate that the combination of WML-01 and fludioxonil, at a significantly lower dosage than fludioxonil alone, exhibits considerable control efficacy against sclerotinia stem rot in rapeseed. Compared to WML-01 alone, the field application amount is significantly reduced while the control efficacy is improved.

[0109] Example 8: Field control efficacy of WML-01 and fludioxonil combined with pepper anthracnose 1. Materials and Methods 1.1 Test Materials 10% WML-01 fludioxonil suspension concentrate, self-made, comprising WML-01 5%, fludioxonil 5%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 10% WML-01 suspension concentrate, self-made, comprising WML-01 10%, MorwetD-425 3%, Witconol NP-100 1%, xanthan gum 0.3%, and water balance, % is by mass percentage, prepared by sand milling process; 30% fludioxonil suspension concentrate, product of Jiangxi Zhengbang Crop Protection Co., Ltd.

[0110] 1.2 Overview of the test site The experiment was conducted in Daxin Town, Fugou County, Zhoukou City, Henan Province, in loam soil, using the chili pepper variety Mibao 19.

[0111] 1.3 Experimental Design Table 20 Experimental Protocol for Chemical Treatments Against Anthracnose in Peppers

[0112] 1.4 Survey Methods and Calculations Five samples were taken from each area, and 20 fruits were investigated at each point. The fruits were graded based on the percentage of diseased area to the total fruit area.

[0113] Grading method: Grade 0: No lesions; Grade 1: The area of ​​lesions is less than 5% of the total fruit area; Grade 3: The area of ​​lesions accounts for more than 5% but less than 10% of the total fruit area; Grade 5: The area of ​​lesions accounts for more than 10% but less than 25% of the total fruit area; Grade 7: The area of ​​lesions accounts for more than 25% but less than 50% of the total fruit area; Level 9: The area of ​​lesions accounts for more than 50% of the total fruit area, or the fruit falls off.

[0114] Methods for calculating drug efficacy: Disease index (%) = ∑(Number of diseased fruits at each level × Representative value at each level) / (Total number of fruits surveyed × Highest representative value) × 100 Control efficacy (%) = (Disease index after treatment in control area - Disease index after treatment in treatment area) / Disease index after treatment in control area × 100 2. Experimental Results Table 21. Control efficacy of chemical treatments against anthracnose in peppers.

[0115] Note: * The average of 4 repetitions; ** The significance level for the analysis of variance was p = 0.05.

[0116] As can be seen from the table above, after two applications, the control efficacy of 200 ml (20 g active ingredient) and 100 ml (10 g active ingredient) of 10% WML-01·fludioxonil suspension against pepper anthracnose was 90.58% and 86.67%, respectively, which was significantly better than the single treatment of fludioxonil (9 g active ingredient) and the single treatment of WML-01 (20 g active ingredient).

[0117] The above results indicate that the combination of WML-01 and fludioxonil, at a similar dosage to fludioxonil alone, exhibits excellent control efficacy against pepper anthracnose. Compared to WML-01 alone, it shows superior control efficacy at comparable dosages, and its control efficacy is also higher than that of WML-01 alone when the dosage is significantly reduced.

[0118] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made based on the present invention. Therefore, such modifications and improvements, which do not depart from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. An agricultural bactericidal composition, characterized in that, The active ingredients of the bactericidal composition include WML-01 and fludioxonil, wherein the mass ratio of WML-01 to fludioxonil is 10:1 to 1:10, and the structural formula of WML-01 is shown in Formula I: 。 2. The agricultural bactericidal composition according to claim 1, characterized in that, The mass ratio of WML-01 to fludioxonil is 10:1 to 1:

1.

3. The agricultural bactericidal composition according to claim 1, characterized in that, The mass ratio of WML-01 to fludioxonil is 3:1 to 1:

10.

4. A bactericidal agent, characterized in that, The bactericide comprises the agricultural bactericide composition according to any one of claims 1-3.

5. The bactericidal agent according to claim 4, characterized in that, The bactericidal formulation is available in the form of seed coating agent, suspension, emulsion, microemulsion, emulsifiable concentrate, microcapsule suspension, nanoformulation, granules, wettable powder, or water-dispersible granules.

6. The bactericidal agent according to claim 4, characterized in that, The bactericidal preparation also includes adjuvants or carriers that assist the agricultural bactericidal composition, wherein the adjuvants are xanthan gum, wetting agents, dispersants, defoamers, antifreeze agents, or warning colors.

7. The bactericidal agent according to claim 6, characterized in that, The wetting agent is nonylphenol polyoxyethylene ether, alkylphenol polyoxyethylene ether, or alkyl naphthalene sulfonate; the dispersant is sodium salt of alkyl naphthalene sulfonic acid condensate or sulfonate of alkyl naphthalene sulfonic acid condensate; the defoamer is n-octanol or organosilicon; the antifreeze agent is ethylene glycol; and the warning color is basic rose essence, golden red, or sun-resistant peach red.

8. The application of the agricultural fungicide composition according to any one of claims 1-3 or the fungicide preparation according to any one of claims 4-7 in the control of plant diseases, wherein the plant disease is rice bakanae disease. Fusarium fujikuroi , Wheat stem rot Fusarium pseudograminearum wheat scab Fusarium graminearum , soybean root rot Fusarium spp., rice blast Pyricularia oryzae Anthracnose of peppers Colletotrichum spp. or rapeseed sclerotinia stem rot Sclerotinia sclerotiorum One or more of them.

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