Synergistic composition for preventing and controlling cycad anthracnose

Abstract

The present invention belongs to the technical field of agricultural disease prevention and control, and specifically relates to a synergistic composition for preventing and treating cycad anthracnose. A synergistic composition, the active ingredients of which are formed by a binary compound of osthole and pyraclostrobin, myclobutanil or flusilazole, and the mass ratio of the osthole to pyraclostrobin, myclobutanil or flusilazole is 1-100:100-1. When osthole is compounded with pyraclostrobin, myclobutanil or flusilazole in the synergistic composition of the present invention, it shows a synergistic effect on the cycad anthracnose pathogen within a certain mass ratio range, which can improve the prevention and control effect of cycad anthracnose, reduce the amount of pesticide used, reduce the cost of prevention and control, and alleviate environmental pollution. In addition, the mechanism of action of osthole is different from that of other ingredients, which can delay the development of pathogen resistance, reduce the risk of drug resistance, and extend the service life of the agent, which is of great significance to the comprehensive management of agricultural resistant diseases.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural disease prevention and control, and particularly relates to a synergistic composition for preventing and controlling cycad anthracnose. Background Art

[0002] Anthracnose of cycads is caused by the fungus Colletotrichum sp., and the symptoms vary depending on the plant species and the growth of the pinnae. One type is more common on older leaves, with the disease starting at the edges or tips. The lesions have inconspicuous whorls, and the edges of the lesions are wavy with a yellow halo. When the lesions extend horizontally to the entire cross-section of the pinnae, the upper part of the leaf dies, and the infected part usually does not break or fall off. In the later stages of the disease, the disease resembles a burn. Another type is more common on newly unfolded leaves, with the initial manifestation of chlorosis of the edges, followed by the appearance of water-soaked lesions. The lesions gradually spread from the edges to the veins, and the tips of the pinnae dry out first, shrinking and becoming brittle before falling off.

[0003] During cycad cultivation, spraying chemical agents such as carbendazim, propiconazole, or tebuconazole can control anthracnose in cycads. These agents act directly on the target pathogen and are quick to act. However, with the long-term use of single-ingredient chemical agents, the cycad anthracnose pathogen has developed strong resistance, resulting in a year-on-year decline in the effectiveness of existing chemical agents. This has also led to problems such as increased control costs and environmental pollution.

[0004] Compounding pesticides with different ingredients is an effective approach to addressing resistant agricultural pests and diseases. Pesticide formulation screening can effectively improve actual control efficacy, reduce dosage, lower costs, and slow the development of pesticide resistance in pests and diseases, making it an important means of integrated agricultural pest management. Indoor bioactivity tests have shown that compounding osthole with pyraclostrobin, myclobutanil, or flusilazole in a specific mass ratio has a synergistic effect against the cycad anthracnose pathogen. Currently, there are no reports on compounding osthole for cycad anthracnose.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a synergistic composition for preventing and controlling cycad anthracnose to solve the problem.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A synergistic composition, the active ingredients of which are formed by a binary compound of osthole and pyraclostrobin, myclobutanil or flusilazole, wherein the mass ratio of osthole to pyraclostrobin, myclobutanil or flusilazole is 1-100:100-1.

[0009] Preferably, the mass ratio of osthole to pyraclostrobin is 1-7:15-1.

[0010] Preferably, the mass ratio of osthole to myclobutanil is 1-20:20-1.

[0011] Preferably, the mass ratio of osthole to flusilazole is 1-35:10-1.

[0012] The present invention also provides application of the synergistic composition in preventing and controlling cycad anthracnose.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] The synergistic composition of the present invention, when combined with pyraclostrobin, myclobutanil, or flusilazole, exhibits a synergistic effect against the cycad anthracnose pathogen within a certain mass ratio range. This improves the control of cycad anthracnose, reduces pesticide usage, lowers control costs, and mitigates environmental pollution. Furthermore, osthole, which has a different mechanism of action from the other ingredients, can slow the development of drug resistance in pathogens, reduce the risk of drug resistance, and extend the lifespan of the agent, thus having important implications for the comprehensive management of agricultural resistance diseases. DETAILED DESCRIPTION

[0015] The following is a clear and complete description of the technical solution of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0016] Example :Indoor biological activity test of osthole compound

[0017] 1. Test strain: Colletotrichum sp. isolated from infected cycads and maintained on PDA medium. (PDA medium recipe: 200g peeled potatoes, 20g glucose, 18g agar, 1000mL distilled water, natural pH)

[0018] 2. Test agents

[0019] 95% osthole (Sichuan Puxi'ao Biaowu Technology Co., Ltd.), 92% pyraclostrobin technical (Syngenta Nantong Crop Protection Co., Ltd.), 96% myclobutanil (Jiangsu Good Harvest Wayne Agrochemical Co., Ltd.), 93% flusilazole technical (Shandong Xinlong Group Biotechnology Co., Ltd.)

[0020] The test agent was first dissolved in dimethyl sulfoxide and then diluted with 0.1% Tween-80 aqueous solution to prepare a single-dose stock solution. Multiple groups of proportions were set up, and each single-dose stock solution and proportioned mixture were set with 7 mass concentration gradients according to the equal ratio method.

[0021] 3. Test method (Refer to NY / T 1156.2-2006 Pesticide Indoor Bioassay Test Guidelines Fungicides Part 2: Inhibition of Pathogen Mycelial Growth Test Plate Method)

[0022] Add 9 mL of pre-thawed PDA medium to a sterile Erlenmeyer flask. Quantitatively pipette 1 mL of drug solution, starting from low to high concentration, into each of the flasks. Shake thoroughly and pour into 9 cm diameter Petri dishes to create drug-containing plates of the corresponding concentrations. A treatment without drug was used as a blank control, with eight replicates for each treatment. Use a 5 mm diameter borer to cut a bacterial cake from the edge of the test strain colony. Inoculate the cake onto the center of the drug-containing plate and the blank control plate. Cover the plate and incubate in a 25°C incubator for 4 days. Measure the colony diameter using the cross-hatch method, and calculate the inhibition rate of mycelial growth by different treatments.

[0023]

[0024] 4. Data Analysis

[0025] DPS software was used for data statistical analysis. Linear regression was performed with the logarithm of fungicide concentration as x and the corresponding probability value of mycelial growth inhibition rate as y to obtain the toxicity regression equation and the EC value of the agent. 50 The co-toxicity coefficient (CTC) was calculated according to the Sun Yunpei method, and the synergistic effect of the drug was evaluated based on the calculated co-toxicity coefficient (CTC). CTC ≤ 80 was antagonistic, 80 < CTC < 120 was additive, and CTC ≥ 120 was synergistic. The results are shown in Tables 1-3.

[0026] Table 1 Indoor bioactivity test of osthole and pyraclostrobin against Colletotrichum cycad

[0027] Drug name and ratio EC50(mg / L) ATI TTI CTC Osthole 17.0842 100.0000 -- -- pyraclostrobin 3.6715 465.3194 -- -- Osthole 1: Pyraclostrobin 15 3.1005 551.0144 442.4869 124.5267 Osthole 1: Pyraclostrobin 10 2.6911 634.8408 432.1085 146.9170 Osthole 1: Pyraclostrobin 7 3.3117 515.8740 419.6544 122.9283 Osthole 1: Pyraclostrobin 3 2.4723 691.0246 373.9895 184.7711 Osthole 1: Pyraclostrobin 1 4.7072 362.9376 282.6597 128.4009 Osthole 3: Pyraclostrobin 1 6.4629 264.3426 191.3298 138.1607 Osthole 7: Pyraclostrobin 1 8.1011 210.8874 145.6649 144.7757

[0028] As shown in Table 1, after osthole and pyraclostrobin were combined, the co-toxicity coefficients against Colletotrichum cycadii were all greater than 120 within the mass ratio range of 1-7:15-1, showing a synergistic effect.

[0029] Table 2 Indoor bioactivity test of osthole and myclobutanil against Colletotrichum cycad

[0030] Drug name and ratio EC50(mg / L) ATI TTI CTC Osthole 17.0842 100.0000 -- -- Myclobutanil 5.3884 317.0552 -- -- Osthole 1: Myclobutanil 20 4.3509 392.6590 306.7192 128.0190 Osthole 1: Myclobutanil 15 3.9424 433.3452 303.4892 142.7877 Osthole 1: Myclobutanil 10 2.1174 806.8480 297.3229 271.3710 Osthole 1: Myclobutanil 7 4.1878 407.9517 289.9233 140.7102 Osthole 1: Myclobutanil 3 1.7059 1001.4772 262.7914 381.0921 Osthole 1: Myclobutanil 1 5.0198 340.3363 208.5276 163.2092 Osthole 3: Myclobutanil 1 8.9002 191.9530 154.2638 124.4317 Osthole 7: Myclobutanil 1 10.2831 166.1386 127.1319 130.6821 Osthole 10: Myclobutanil 1 11.1992 152.5484 119.7323 127.4079 Osthole 15: Myclobutanil 1 9.8575 173.3117 113.5659 152.6089 Osthole 20: Myclobutanil 1 12.6626 134.9186 110.3360 122.2798

[0031] As shown in Table 2, after osthole and myclobutanil were mixed, the co-toxicity coefficient against Colletotrichum cycadii was greater than 120 in the mass ratio range of 1-5:15-1, showing a synergistic effect.

[0032] Table 3 Indoor bioactivity test of osthole and flusilazole complex against cycad anthracnose

[0033] Drug name and ratio EC50(mg / L) ATI TTI CTC Osthole 17.0842 100.0000 -- -- Flusilazole 1.6347 1045.0970 -- -- Osthole 1: Flusilazole 10 1.4317 1193.2807 959.1791 124.4065 Osthole 1: Flusilazole 7 0.8693 1965.2824 926.9598 212.0138 Osthole 1: Flusilazole 3 1.3213 1292.9842 808.8227 159.8600 Osthole 1: Flusilazole 1 2.4107 708.6821 572.5485 123.7768 Osthole 3: Flusilazole 1 1.6550 1032.2779 336.2742 306.9750 Osthole 7: Flusilazole 1 3.7823 451.6881 218.1371 207.0661 Osthole 10: Flusilazole 1 6.7519 253.0280 185.9179 136.0966 Osthole 15: Flusilazole 1 5.2961 322.5808 159.0686 202.7935 Osthole 20: Flusilazole 1 8.5186 200.5517 145.0046 138.3071

[0034] As shown in Table 3, after osthole and flusilazole were mixed, the co-toxicity coefficient against Colletotrichum cycadii was greater than 120 within the mass ratio range of 1-35:10-1, showing a synergistic effect.

[0035] In summary, when osthole is compounded with pyraclostrobin, myclobutanil or flusilazole in the synergistic composition of the present invention, it exhibits a synergistic effect on the cycad anthracnose pathogen within a certain mass ratio range, which can improve the control effect of cycad anthracnose, reduce the amount of pesticide used, reduce the control cost and alleviate environmental pollution.

[0036] The foregoing descriptions of specific exemplary embodiments of the present invention are for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many variations and modifications are possible in light of the foregoing teachings. The exemplary embodiments have been selected and described for the purpose of explaining the specific principles of the invention and their practical application, thereby enabling those skilled in the art to realize and utilize a variety of exemplary embodiments of the invention and various options and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A synergistic composition for use in preventing and controlling cycad anthracnose, characterized in that: The active ingredients of the synergistic composition are prepared by combining osthole and myclobutanil in a binary mixture, and the mass ratio of osthole to myclobutanil is 1-20:20-1.

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