A bactericidal composition for preventing and treating red brown spot disease of Macadamia integrifolia

Abstract

The present invention belongs to the technical field of pesticides, and particularly relates to a bactericidal composition for preventing and controlling red-brown spot disease of macadamia nuts. A bactericidal composition for preventing and controlling red-brown spot disease of macadamia nuts, the active ingredients of which are compounded by berberine and zhongshengmycin, fenoxanil or isopyrazam. The bactericidal composition of the present invention has a synergistic effect on inhibiting the growth of the pathogen of red-brown spot disease of macadamia nuts. Compared with a single active ingredient, it can improve the control effect on red-brown spot disease of macadamia nuts and reduce the control cost.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and particularly relates to a fungicide composition for preventing and treating macadamia nut red brown spot disease. Background Art

[0002] Macadamia nut, also known as macadamia nut, is a plant of the genus Macadamia native to Australia. It not only has high economic value, but also has good nutritional and medicinal value. It is known as the "King of Dried Fruits". Macadamia nuts are prone to many diseases and pests, with more than 30 diseases and more than 300 pests, including the macadamia red brown spot disease caused by infection with Calonectria pentaseptata. Macadamia red brown spot disease mainly harms leaves and fruits. When it harms the fruit, reddish-brown circular spots will form on the peel, eventually spreading to the entire fruit, causing the fruit to fall off. When it harms the leaves, the disease usually affects the entire tip and the entire fruit. In the early stage of the disease, there are many small reddish-brown circular spots on the leaves, and the outer circle of the small circular spots is water-soaked and yellow. In the later stage, the reddish-brown spots expand and become connected, forming large reddish-brown necrotic spots, which affects the normal growth and yield of macadamia nuts.

[0003] Chemical agents are a common method for controlling macadamia red brown spot disease. However, long-term application of a single chemical agent can lead to resistance in the pathogen. As resistance accumulates, the effectiveness of existing chemical agents decreases. Therefore, the development of new, highly effective agents for controlling macadamia red brown spot disease is crucial.

[0004] Combining different pesticide active ingredients is an effective and efficient way to develop and research new pesticides. The inventors discovered through laboratory experiments that combining berberine with zhongshengmycin, cyproconazole, or pyraclostrobin has a synergistic effect in inhibiting the growth of the pathogen causing macadamia red spot disease, providing support for the development of agents to control macadamia red spot disease. Currently, no reports on such combinations have been found.

[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 object of the present invention is to provide a fungicide composition for preventing and treating macadamia nut red brown spot disease, so as to solve the problems existing in preventing and treating the disease with a single chemical agent.

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

[0008] A fungicide composition for preventing and treating macadamia nut red brown spot disease, wherein the active ingredient is a compound of berberine, zhongshengmycin, cyproconazole or pyraclostrobin.

[0009] Preferably, the mass ratio of berberine to zhongshengmycin is 1-20:20-1.

[0010] Preferably, the mass ratio of berberine to pyraclostrobin is 1-10:30-1.

[0011] Preferably, the mass ratio of berberine to sedaxane is 1-5:15-1.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The bactericidal composition of the present invention has a synergistic effect on inhibiting the growth of the pathogen of red brown spot disease of macadamia nuts. Compared with a single active ingredient, it can improve the control effect on red brown spot disease of macadamia nuts and reduce the control cost, providing support for the development of a new and highly effective agent for controlling red brown spot disease of macadamia nuts.

[0014] (2) The bactericidal composition of the present invention can delay the development of pathogen drug resistance and can, to a certain extent, extend the service life of the agent. Detailed implementation mode

[0015] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present invention.

[0016] Example

[0017] 1. Test strains

[0018] The pathogen of red brown spot disease of macadamia nuts (Calonectria pentaseptata) was collected from diseased macadamia nut leaves, isolated in the laboratory, and stored on PDA medium.

[0019] 2. Test agents

[0020] 98% berberine technical, 99% zhongshengmycin technical, 95% pyraclostrobin technical, 92% sedaxane technical. The above agents are all commercially available.

[0021] The test agents were first dissolved in dimethyl sulfoxide and then diluted with a 0.1% Tween-80 aqueous solution to form a single-agent mother liquor. Multiple groups of ratios were set, and 5 mass concentration gradients were set for each single-agent mother liquor and the mixed agent of the ratio according to the equal ratio method.

[0022] 3. Test method

[0023] The hyphae growth rate method was used. 9 mL of pre-melted PDA medium was added to a sterile conical flask. 1 mL of drug solution was quantitatively pipetted sequentially from low to high concentration and added to each of the above conical flasks. After thorough shaking, the mixture was poured into a 9 cm diameter Petri dish to prepare drug-containing plates of the corresponding concentrations. A treatment without drug was set as a blank control, with eight replicates for each treatment. A 5 mm diameter cake was cut from the edge of the test strain colony using a hole punch. This was inoculated onto the center of the drug-containing plate and the blank control plate. The plates were covered and incubated at 25°C. When the blank control colony diameter grew to more than two-thirds of the Petri dish diameter, the colony diameter was measured using the cross-hatch method, and the mycelial growth inhibition rate of the different treatments was calculated.

[0024]

[0025] 4. Data Analysis

[0026] DPS software was used for data statistical analysis. The logarithmic value of fungicide concentration was taken as x and the corresponding probability value of mycelial growth inhibition rate was taken as y for linear regression. The virulence regression equation and the virulence EC value of the agent to the target pathogen were obtained. 50 The co-toxicity coefficient (CTC) was calculated according to the Sun Yunpei method.

[0027] 5. Measurement results

[0028] The synergistic effect of the agents was evaluated based on the calculated co-toxicity coefficient (CTC). CTC ≤ 80 indicated an antagonistic effect, 80 < CTC < 120 indicated an additive effect, and CTC ≥ 120 indicated a synergistic effect. The results are shown in Tables 1-3.

[0029] Table 1 Indoor bioactivity test of berberine and zhongshengmycin against macadamia nut red brown spot pathogen

[0030] Name and ratio of medicaments EC50 (mg / L) ATI TTI CTC Berberine 12.691 100.000 -- -- Zhongshengmycin 4.317 293.977 -- -- Berberine 1: Zhongshengmycin 20 2.403 528.132 284.740 185.478 Berberine 1: Zhongshengmycin 10 2.833 447.970 276.343 162.107 Berberine 1: Zhongshengmycin 5 4.027 315.148 261.648 120.447 Berberine 1: Zhongshengmycin 1 5.195 244.293 196.989 124.014 Berberine 5: Zhongshengmycin 1 3.514 361.155 132.330 272.921 Berberine 10: Zhongshengmycin 1 2.801 453.088 117.634 385.167 Berberine 20: Zhongshengmycin 1 6.919 183.422 109.237 167.912

[0031] As shown in Table 1, after berberine and zhongshengmycin were combined, the co-toxicity coefficient against macadamia nut red brown spot pathogen was greater than 120 in the mass ratio range of 1-20:20-1, showing a synergistic effect.

[0032] Table 2 Indoor bioactivity test of berberine and cyanobacterium against macadamia nut red brown spot pathogen

[0033] Name and ratio of medicaments EC50 (mg / L) ATI TTI CTC Berberine 12.691 100.000 -- -- Phenamacril 0.763 1663.303 -- -- Berberine 1: Phenamacril 30 0.592 2143.750 1612.874 132.915 Berberine 1: Phenamacril 20 0.341 3721.701 1588.860 234.237 Berberine 1: Phenamacril 10 0.675 1880.148 1521.184 123.598 Berberine 1: Phenamacril 5 0.710 1787.465 1402.752 127.426 Berberine 1: Phenamacril 1 1.181 1074.598 881.651 121.885 Berberine 5: Phenamacril 1 2.136 594.148 360.550 164.789 Berberine 10: Phenamacril 1 4.318 293.909 242.118 121.391

[0034] As shown in Table 2, after berberine and cyproconazole were combined, the co-toxicity coefficient against macadamia nut red brown spot pathogen was greater than 120 in the mass ratio range of 1-10:30-1, showing a synergistic effect.

[0035] Table 3 Indoor bioactivity test of berberine and pyraclostrobin against macadamia nut red brown spot pathogen

[0036]

[0037]

[0038] As can be seen from Table 3, after the compounding of berberine and pyraclostrobin, the co-toxicity coefficients against the pathogen of red-brown spot of Macadamia integrifolia are all greater than 120 in the mass ratio range of 1-10:15-1, showing a synergistic effect.

[0039] In summary, after the compounding of berberine with zhongshengmycin, cyprodinil or pyraclostrobin, it has a good synergistic effect, can improve the control effect on the red-brown spot of Macadamia integrifolia, can reduce the dosage of pesticides, and lower the control cost and pesticide residues.

[0040] The foregoing description of specific exemplary embodiments of the invention has been presented for purposes of illustration and example. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that many modifications and variations are possible in light of the above teaching. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the invention and its practical application so that those skilled in the art can implement and utilize the various different exemplary embodiments of the invention as well as various different selections and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. Use of a bactericidal composition in controlling red-brown spot disease of macadamia nuts, characterized in that, The active ingredient of the bactericidal composition is composed of berberine and Zhongshengmycin, and the mass ratio of berberine to Zhongshengmycin is 1-20:20-1.

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