Biological pesticide for preventing and treating oil olive anthracnose

Abstract

The present application belongs to the technical field of biological pesticides, and particularly relates to a kind of biological pesticides for preventing and treating oil olive anthracnose.A kind of biological pesticides for preventing and treating oil olive anthracnose, its effective component is compounded by Trichoderma harzianum and polyoxin, berberine or difenachonazole, wherein the Trichoderma harzianum is 200 billion cfu / g of Trichoderma harzianum DS-10 mother drug.The Trichoderma harzianum of the present application is compounded with polyoxin, berberine or difenachonazole, and the co-toxicity coefficient of the compound to oil olive anthracnose is greater than 120, which shows synergistic effect, can improve the prevention and treatment effect on oil olive anthracnose, reduce the use amount of pesticide and reduce the prevention and treatment cost.

Description

Technical Field

[0001] This invention belongs to the field of biological pesticide technology, specifically relating to a biological pesticide for the prevention and control of avocado anthracnose. Background Technology

[0002] Colletotrichum gloeosporioides penz. infects avocados, causing anthracnose, a fungal disease. Anthracnose damages the flowers, fruits, leaves, and branches of the plant, with fruits being the most severely affected, impacting yield. While chemical pesticides can effectively control anthracnose during avocado cultivation, long-term reliance on single-use pesticides has led to increased pathogen resistance and a rising risk of pesticide resistance. Furthermore, high doses of pesticides can result in excessive pesticide residues in the fruit, posing a health risk. Therefore, developing green, safe, and efficient pesticides is essential.

[0003] Trichoderma harzianum is a microbial fungicide that antagonizes various plant pathogens through multiple mechanisms, including nutrient competition, hyperparasitism, and cell wall degrading enzymes, thus providing both protective and curative effects. Trichoderma harzianum not only effectively inhibits pathogen growth but also produces compounds that stimulate plant growth and induce plant defense responses. It improves the soil root microenvironment, enhances plant vigor and disease resistance, and ultimately increases crop yield and profitability.

[0004] Combining different fungicidal components is one of the effective and convenient ways to control drug-resistant diseases and develop new agents. Currently, there are no reports of combining *Trichoderma harzianum* with polyoxin, berberine, or difenoconazole. Summary of the Invention

[0005] The purpose of this invention is to provide a biological pesticide for controlling avocado anthracnose, which can improve the control effect of avocado anthracnose, reduce the risk of pesticide resistance, and is environmentally friendly, green and safe.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A biological pesticide for controlling avocado anthracnose, the active ingredient of which is a compound of Trichoderma harzianum, polyoxin, berberine or difenoconazole, wherein the Trichoderma harzianum is the DS-10 mother drug of Trichoderma harzianum with a concentration of 20 billion CFU / g.

[0008] Preferably, the mass ratio of Trichoderma harzianum to polyoxin is 1-15:1.

[0009] Preferably, the mass ratio of Trichoderma harzianum to berberine is 1-20:9-1.

[0010] Preferably, the mass ratio of Trichoderma harzianum to difenoconazole is 1-40:4-1.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] (1) The present invention combines Trichoderma harzianum with polyoxin, berberine or difenoconazole, and the co-toxicity coefficient against avocado anthracnose fungus is greater than 120, which shows a synergistic effect. This can improve the control effect of avocado anthracnose, reduce the amount of pesticides used, and reduce the control cost.

[0013] (2) The biological pesticide of the present invention can delay the emergence and development of drug resistance in avocado anthracnose fungus and reduce the risk of drug resistance.

[0014] (3) The biological pesticide of the present invention is environmentally friendly, green and safe. Detailed Implementation

[0015] The technical solution of this invention patent will be clearly and completely described below.

[0016] Example

[0017] 1. Test strain

[0018] Diseased fruit samples of avocados were collected, and *Colletotrichum gloeosporioides* penz. were isolated, purified, and identified in the laboratory. The samples were then propagated and cultured on PDA medium for 3 days for later use.

[0019] 2. Test reagents

[0020] 20 billion CFU / g Trichoderma harzianum DS-10 technical material (Xi'an Dingsheng Biochemical Co., Ltd.), 99% polyoxin technical material (Hubei Shixing Chemical Co., Ltd.), 98% berberine technical material (Shanghai Yuanye Biotechnology Co., Ltd.), and 94% difenoconazole technical material (Jiangsu Youjia Plant Protection Co., Ltd.).

[0021] Trichoderma harzianum DS-10 mother drug was diluted with 0.1% Tween-80 aqueous solution to prepare a single-agent mother liquor; other agents were dissolved in dimethyl sulfoxide and then diluted with 0.1% Tween-80 aqueous solution to prepare single-agent mother liquors; multiple ratios were set up, and each single-agent mother liquor and ratio mixture was set with 5 mass concentration gradients according to the equal ratio method.

[0022] 3. Test methods

[0023] The mycelial growth rate method was used. 9 mL of pre-melted PDA medium was added to a sterile Erlenmeyer flask. Quantitatively measured 1 mL of drug solution, from low to high concentration, was added to each flask. After thorough mixing, the solution was poured into 9 cm diameter Petri dishes to prepare drug-containing plates of the corresponding concentrations. A blank control without the drug was also included. Each treatment had 10 replicates. Mycelial cakes were cut from the edge of the colonies of the tested strain using a 5 mm diameter punch and inoculated into the center of both the drug-containing and blank control plates. The plates were then capped and incubated at 25°C for 3 days. The colony diameter was measured using the cross-sectional method, and the inhibition rate of mycelial growth by different treatments was calculated.

[0024]

[0025] 4. 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.

[0026]

[0027] In the above formula: ATI -- the measured toxicity index of the mixture; S -- the EC50 of the standard agent. 50 The unit is mg / L; M -- EC of the mixture 50 The unit is mg / L.

[0028] TTI = TI A ×P A +TI B ×P B

[0029] In the above formula: TTI -- theoretical toxicological index of the mixture; TI A --Toxicity index of drug A; P A --Percentage content of drug A in the mixture, expressed as a percentage (%); TI B --Toxicity index of drug B; P B --The percentage content of drug B in the mixture, expressed as a percentage (%).

[0030]

[0031] In the above formula: CTC -- co-toxicity coefficient; ATI -- measured toxicity index of the mixture; TTI -- theoretical toxicity index of the mixture.

[0032] 5. Measurement Results

[0033] 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 1-3.

[0034] Table 1. Indoor bioactivity assay of Trichoderma harzianum combined with polyoxin against Avocado anthracnose.

[0035] Trichoderma harzianum 80.6952 100.0000 -- -- Polyoxin 9.5106 848.4764 -- -- Trichoderma harzianum 15: Polyoxin 1 52.1703 154.6765 146.7798 105.3800 Trichoderma harzianum 10: Polyoxin 1 37.9229 212.7875 168.0433 126.6266 Trichoderma harzianum 5: Polyoxin 1 20.0267 402.9381 224.7461 179.2859 Trichoderma harzianum 3: Polyoxin 1 12.1719 662.9631 287.1191 230.9018 Trichoderma harzianum 1: Polyoxin 1 10.5766 762.9597 474.2382 160.8811

[0036] Table 1 shows that when Trichoderma harzianum and polyoxin are combined at a mass ratio of 15:1, they exhibit an additive effect; when the mass ratio is 10:1:1, they exhibit a synergistic effect. This indicates that the combination of Trichoderma harzianum and polyoxin can improve the control effect against avocado anthracnose.

[0037] Table 2. Indoor bioactivity assay of Trichoderma harzianum combined with berberine against Avocado anthracnose.

[0038]

[0039]

[0040] Table 2 shows that when Trichoderma harzianum and berberine are combined in a mass ratio of 1-20:9-1, a synergistic effect is observed. This indicates that the combination of Trichoderma harzianum and berberine can improve the control effect against avocado anthracnose.

[0041] Table 3. Indoor bioactivity assay of Trichoderma harzianum and difenoconazole combination against Avocado anthracnose pathogen.

[0042] Trichoderma harzianum 80.6952 100.0000 -- -- difenoconazole 4.9530 1629.2187 -- -- Trichoderma harzianum 1: difenoconazole 4 4.3377 1860.3223 1323.3749 140.5741 Trichoderma harzianum 1: Difenoconazole 1 7.1702 1125.4247 864.6093 130.1657 Trichoderma harzianum 3: difenoconazole 1 10.1745 793.1122 482.3047 164.4422 Trichoderma harzianum 5: difenoconazole 1 15.0550 536.0027 354.8698 151.0421 Trichoderma harzianum 10: difenoconazole 1 8.1943 984.7723 239.0199 412.0044 Trichoderma harzianum 20: difenoconazole 1 26.9770 299.1259 172.8199 173.0853 Trichoderma harzianum 40: difenoconazole 1 44.1079 182.9495 137.2980 133.2500

[0043] Table 3 shows that when *Trichoderma harzianum* and difenoconazole are combined in a mass ratio of 1-40:4-1, a synergistic effect is observed. This indicates that the combination of *Trichoderma harzianum* and difenoconazole can improve the control effect against avocado anthracnose.

[0044] In conclusion, the combination of Trichoderma harzianum with polyoxin, berberine, or difenoconazole exhibits a co-toxicity coefficient greater than 120 against avocado anthracnose, demonstrating a synergistic effect and thus improving the control efficacy against avocado anthracnose.

[0045] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A biological pesticide for controlling anthracnose in avocados, characterized in that, Its active ingredient is a compound of Trichoderma harzianum and berberine, wherein Trichoderma harzianum is the DS-10 mother drug of Trichoderma harzianum with a concentration of 20 billion CFU / g; and the mass ratio of Trichoderma harzianum to berberine is 1-20:9-1.

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