A composition for efficiently preventing and controlling plant fungal diseases and nematode diseases

Abstract

The present application belongs to the technical field of pesticides, and particularly relates to a composition for efficiently preventing and controlling plant fungal diseases and nematode diseases. The effective components of the synergistic composition are composed of double acrylmycin, flufenoxystrobin and fluopicolide. After the three components of double acrylmycin, flufenoxystrobin and fluopicolide are compounded, the composition has good bacteriostatic activity and nematocidal activity, which has important significance for effectively preventing and controlling wheat foot rot, potato late blight and tomato root knot nematode disease in current agricultural production. In addition, the composition can prolong the service life of the three fungicides of double acrylmycin, flufenoxystrobin and fluopicolide, effectively delay the occurrence and development speed of crop diseases to the three components, and achieve the goal of 'one spray, multiple effects' for crop diseases.

Description

Technical Field

[0001] This invention belongs to the field of pesticide technology, specifically to a composition for the efficient control of plant fungal diseases and nematode diseases. Background Technology

[0002] Utilizing resistance genes to mediate crop disease resistance in breeding is an effective disease control measure, and my country has made significant progress in this area. However, due to the complexity of plant pathogens in my country's agricultural sector, superior disease-resistant crop varieties are rarely used in production. Consequently, current agricultural disease control still relies primarily on the application of chemical fungicides. While chemical fungicides are the main means of controlling crop diseases, the complexity of plant pathogens in my country and the limited target of fungicides make it difficult to achieve the goal of "simultaneous prevention and treatment" of multiple crop diseases, such as fungal and nematode diseases, with a single fungicide.

[0003] Bistyrax is a novel carboxylic acid amide fungicide developed by Syngenta Crop Protection. Its mechanism of action involves inhibiting phosphate synthesis. It exhibits high activity against spore germination and effectively inhibits mycelial growth and spore formation. It also demonstrates excellent field control efficacy against most foliar and fruit diseases caused by oomycetes. Currently, bistyrax is officially registered in my country for the control of oomycete diseases affecting vegetables (or fruit trees and fruits) such as peppers, tomatoes, potatoes, grapes, and watermelons. However, due to its single target, the use of bistyrax alone to control plant diseases can easily lead to pathogen resistance, resulting in poor efficacy.

[0004] Fluopyram is a novel succinate dehydrogenase inhibitor fungicide developed by Syngenta Crop Protection. It acts on succinate dehydrogenase and its mixture with difenoconazole was registered in China in 2020 for the control of wheat scab and rapeseed sclerotinia rot. Studies have shown that fluopyram and its compound formulations are effective in controlling leaf spot, powdery mildew, gray mold, and various fungal diseases caused by Fusarium on wheat, rice, citrus, and apples. Due to its excellent field efficacy, low environmental risk, relatively strong systemic activity, long-lasting effect, good stability, and low likelihood of cross-resistance, it has become a substitute or alternative fungicide for benzimidazoles, triazoles, and methoxyacrylates. However, because of its single target, prolonged use of fluopyram alone for plant disease control can easily lead to the development of resistance in pathogens.

[0005] Fluopyram is a novel pyridylethylbenzamide-based broad-spectrum, systemic fungicide and nematicide developed by Bayer Crop Science in 2003. It was registered in my country in 2012 for the control of gray mold, powdery mildew, sclerotinia rot, and brown rot on various crops, including grapes, pears, stone fruits, vegetables, and field crops. It also shows excellent control efficacy against root-knot nematodes in cucumbers, tomatoes, and bananas. Fluopyram is generally believed to act on complex II of the mitochondrial respiratory electron transport chain, inhibiting the activity of its target, succinate dehydrogenase, thereby blocking electron transport and interfering with respiration. This results in the inability to provide energy to the body's tissues, ultimately killing the target or inhibiting its growth and development. Studies have shown that fluopyram is not only effective in controlling plant nematode diseases such as tomato root-knot nematode and sweet potato stem nematode, but also has excellent control effects against gray mold, powdery mildew, and sclerotinia rot. At the same time, because it targets only one plant disease, pathogens are prone to developing resistance to it when fluopyram is used for a long time and in a single application to control plant diseases.

[0006] Through indoor experiments, the inventors discovered that when dimethomorph, fluopyram, and fluopyram are combined in a certain mass ratio, they exhibit good antibacterial activity against Fusarium pseudograminearum and Phytophthora infestans, while also showing good insecticidal activity against Meloidogyne incognita. This achieves the goal of "multiple effects with one spray" against crop diseases.

[0007] Currently, there are no reports of a combination of dimethomorph, fluopyram, and fluopyram.

[0008] 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

[0009] The purpose of this invention is to provide a composition for the efficient control of plant fungal and nematode diseases, which has good antibacterial activity against Fusarium graminearum and good insecticidal activity against southern root-knot nematodes, achieving the goal of "one spray for multiple effects" against crop diseases.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] The first objective of this invention is to provide a synergistic composition whose active ingredients consist of diacetylaminophen, fluopyram, and fluopyram.

[0012] Preferably, the mass ratio of dimethomorph, fluopyram, and fluopyram is 7:3:1-9.

[0013] Preferably, the mass ratio of dimethomorph, fluopyram, and fluopyram is 7:3:7.

[0014] A second objective of this invention is to provide the application of the aforementioned synergistic composition in the control of plant fungal diseases.

[0015] A third objective of this invention is to provide the application of the aforementioned synergistic composition in the control of plant nematode diseases.

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

[0017] (1) The present invention combines dimethomorph, fluopyram and fluopyram, which exhibits good antibacterial and insecticidal activity. This is of great significance for the effective control of wheat stem base rot, potato late blight and tomato root-knot nematode disease in current agricultural production.

[0018] (2) The composition of the present invention can extend the service life of the three fungicides, namely, dimethomorph, fluopyram and fluopyram, and can effectively delay the occurrence and development of resistance to these three fungicides in crop diseases, thus achieving the goal of "one spray for multiple effects" in the prevention and control of crop diseases. Detailed Implementation

[0019] The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the descriptions in the embodiments are for illustrative purposes only and should not, and will not, limit the invention as detailed in the claims.

[0020] Example 1

[0021] 1. Test strain

[0022] Fusarium pseudograminearum

[0023] Phytophthora infestans

[0024] 2. Culture medium

[0025] PDA medium: 200g potato, 20g glucose, 15g agar, 1000mL distilled water, natural pH.

[0026] Rye culture medium: 60g rye, 20g sucrose, 17g agar, 1000mL distilled water, natural pH.

[0027] 3. Test reagents

[0028] 93% dimethomorph technical grade, 98% fluopyram technical grade, and 96% fluopyram technical grade are all commercially available.

[0029] The test reagent was first dissolved in dimethyl sulfoxide, and then diluted with 0.1% Tween-80 aqueous solution to prepare a single-agent stock solution. Multiple ratios were set up, and five mass concentration gradients were set for each single agent and ratio mixture according to the proportional method.

[0030] 4. Test methods

[0031] The mycelial growth rate method was used. 9 mL of pre-melted culture medium was added to a sterile Erlenmeyer flask. PDA medium was used for *Fusarium graminearum*, and rye medium was used for *Phytophthora infestans*. Then, 1 mL of the drug solution was quantitatively pipetted sequentially from low to high concentration and added to the aforementioned Erlenmeyer flasks. After thorough mixing, the solution was poured into 9 cm diameter petri dishes to prepare plates containing the corresponding drug concentrations. A 0.1% Tween-80 treatment was used as a blank control, and each treatment was replicated 10 times.

[0032] Using a punch, 5mm diameter mycelial discs were cut from the edge of the colonies of the tested strains and inoculated into the center of both the drug-containing and blank control plates. The plates were then covered and incubated in a constant temperature incubator. The culture conditions for *Fusarium graminearum* were 25℃, with a light:dark ratio of 12h:12h; the culture conditions for *Phytophthora infestans* were 18℃, in darkness. When the colony diameter of the blank control reached 2 / 3 of the plate diameter, the colony diameter was measured using the cross-sectional method, and the inhibition rate of mycelial growth by different treatments was calculated.

[0033]

[0034] 5. Data Analysis: Statistical analysis was performed using DPS software. Linear regression was conducted with the logarithm of the fungicide concentration as x and the corresponding mycelial growth inhibition rate probability value as y to derive the virulence regression equation and the EC50 of the fungicide against the target pathogen. 50 The value was calculated, and the cotoxicity coefficient (CTC) was calculated according to Sun Yunpei's method.

[0035] 6. Measurement Results

[0036] The synergistic effect of the drug was evaluated based on 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 1-2.

[0037] Table 1. Activity of the combination of dimethomorph, fluopyram, and fluopyram against Fusarium graminearum.

[0038] Drug Name and Proportion EC50 (mg / L) ATI TTI CTC Diyrylamide (A) 153.266 100.000 -- -- Fluopyram (B) 0.027 567651.852 -- -- Fluopyram (C) 0.451 33983.592 -- -- A7: B3: C1 11.374 1347.512 157967.195 0.853 A7: B3: C2 8.764 1748.813 147635.228 1.185 A7:B3:C3 10.368 1478.260 138892.795 1.064 A7: B3: C4 3.756 4080.564 131399.280 3.105 A7: B3: C5 1.387 11050.180 124904.901 8.847 A7: B3: C6 0.535 28647.850 119222.319 24.029 A7:B3:C7 0.013 1178969.231 114208.276 1032.298 A7: B3: C8 0.354 43295.480 109751.350 39.449 A7: B3: C9 0.439 34912.528 105763.573 33.010

[0039] As shown in Table 1, when the mass ratio of dimethomorph, fluopyram and fluopyram were combined, the co-toxicity coefficient against Fusarium wilt pathogen of wheat stem rot was greater than 120, indicating a synergistic effect. The co-toxicity coefficient reached 1032.298, showing a significant synergistic effect.

[0040] Table 2. Activity of the combination of dimethomorph, fluopyram, and fluopyram against pathogenic Phytophthora.

[0041] Drug Name and Proportion EC50 (mg / L) ATI TTI CTC Diyrylamide (A) 0.064 100.000 -- -- Fluopyram (B) 163.462 0.039 -- -- Fluopyram (C) 139.243 0.046 -- -- A7: B3: C1 17.287 0.370 63.651 0.582 A7: B3: C2 11.924 0.537 58.351 0.920 A7:B3:C3 8.517 0.751 53.866 1.395 A7: B3: C4 10.853 0.590 50.022 1.179 A7: B3: C5 2.834 2.258 46.690 4.837 A7: B3: C6 0.117 54.701 43.775 124.960 A7:B3:C7 0.103 62.136 41.202 150.807 A7: B3: C8 0.238 26.891 38.916 69.100 A7: B3: C9 0.579 11.054 36.870 29.980

[0042] As shown in Table 2, the co-toxicity coefficients of dimethomorph, fluopyram, and fluopyram, when combined in mass ratios of 7:3:6 and 7:3:7, against the pathogen of potato late blight are greater than 120, indicating a synergistic effect.

[0043] Example 2

[0044] 1. Test pest: Southern root-knot nematode (Meloidogyne incognita)

[0045] 2. Test reagents

[0046] Same as Example 1

[0047] 3. Test methods (Refer to "NT / Y 1833.1-2009 Guidelines for Indoor Bioassay of Pesticides - Nematicides - Part 1: Inhibition of Plant Pathogenic Nematodes - Immersion Method")

[0048] Eggs of root-knot nematodes were collected from the roots of tomato plants, washed with water, and placed on moist filter paper in a petri dish. They were incubated at 25°C to obtain second-instar larvae of the same age. The cultured root-knot nematodes were washed with water, filtered, centrifuged at 1000 r / min for 2 min, the supernatant was discarded, water was added, and centrifuged again. Finally, the root-knot nematodes were resuspended in water to 200 nematodes / mL for later use.

[0049] Using a pipette, add 3 mL of the drug solution sequentially from low to high concentration into each test tube. Then, add 3 mL of the prepared nematode suspension to the test tube, ensuring that the drug solution and nematode suspension are mixed evenly. Use a pipette to transfer a certain volume of the above mixture into the wells of a 24-well biochemical test plate, cover, and incubate at 25°C for 24 hours. Simultaneously, a 0.1% Tween-80 treatment is set up as a blank control.

[0050] Take 1 mL of the mixture from each treatment and observe the mortality of nematodes under a dissecting microscope. Each replicate should include at least 100 nematodes. Record the number of main nematodes and the number of dead nematodes. The criterion for nematode mortality is: the nematode is rigid and cannot bend or move when touched with a hairpin or bamboo needle. Calculate the mortality rate and corrected mortality rate for each treatment based on the survey data.

[0051]

[0052] In the above formula: P -- mortality rate, in %; K -- number of dead insects; N -- total number of insects treated.

[0053]

[0054] In the above formula: P1 -- corrected mortality rate, in %; P t --Treatment mortality rate, in %; P0--Control mortality rate, in %.

[0055] 4. Data Analysis: DPS software was used for statistical analysis of the data. Linear regression was performed with the logarithm of the fungicide concentration as x and the corresponding corrected mortality probability as y to derive the toxicity regression equation and the LC50 of the fungicide's toxicity to the target. 50 The value was calculated, and the cotoxicity coefficient (CTC) was calculated according to Sun Yunpei's method.

[0056] 5. Measurement Results

[0057] The synergistic effect of the drug was evaluated based on 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 3.

[0058] Table 3. Activity of the combination of dimethomorph, fluopyram, and fluopyram against southern root-knot nematodes.

[0059] Drug Name and Proportion LC50 (mg / L) ATI TTI CTC Diyrylamide (A) 208.763 100.000 -- -- Fluopyram (B) 191.576 108.971 -- -- Fluopyram (C) 1.692 12338.239 -- -- A7: B3: C1 65.732 317.597 1215.014 26.139 A7: B3: C2 83.764 249.228 2141.949 11.636 A7:B3:C3 51.654 404.157 2926.279 13.811 A7: B3: C4 29.751 701.701 3598.562 19.499 A7: B3: C5 18.385 1135.507 4181.207 27.157 A7: B3: C6 7.352 2839.540 4691.022 60.531 A7:B3:C7 3.129 6671.876 5140.858 129.781 A7: B3: C8 5.438 3838.967 5540.712 69.287 A7: B3: C9 3.957 5275.790 5898.477 89.443

[0060] As shown in Table 3, when the compound of dimethomorph, fluopyram and fluopyram in a mass ratio of 7:3:7, the co-toxicity coefficient against southern root-knot nematodes is greater than 120, indicating a synergistic effect.

[0061] In summary, the combination of dimethomorph, fluopyram, and fluopyram exhibits good antibacterial and nematicidal activity, which is of great significance for the effective control of plant pathogenic fungal diseases, oomycete diseases, and nematode diseases such as wheat stem base rot, potato late blight, and tomato root-knot nematode disease in current agricultural production.

[0062] The exemplary embodiments have been 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 exemplary embodiments of the invention, as well as various alternatives and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A synergistic composition, characterized in that, Its active ingredients consist of diyrylamide, fluopyram, and fluopyram, with a mass ratio of 7:3:

7.

2. The application of the synergistic composition according to claim 1 in the control of plant fungal diseases, characterized in that, The plant fungal disease is caused by Fusarium pseudograminearum (… Fusarium pseudograminearum ), pathogenic fungus ( Phytophthora infestans )cause.

3. The application of the synergistic composition according to claim 1 in the control of plant nematode diseases, characterized in that, The plant nematode disease is caused by the southern root-knot nematode ( Meloidogyne incognita )cause.

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