Agricultural composition for preventing and treating watermelon anthracnose

Abstract

The invention discloses a bactericidal composition for preventing and treating watermelon anthracnose, the active ingredients of the bactericidal composition are compounded by polygonum cuspidatum extract and matrine, and the mass ratio of the polygonum cuspidatum extract to the matrine is 1: 2-5: 1. After the polygonum cuspidatum extract and the sophocarpidine in the bactericidal composition are compounded, the bactericidal composition has a synergistic effect on melon anthracnose germs, the prevention and treatment effect on watermelon anthracnose can be improved, the pesticide application amount can be reduced, and pesticide residues can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of pesticides, and in particular belongs to an agricultural composition for preventing and treating watermelon anthracnose. Background Art

[0002] Watermelon anthracnose is a worldwide fungal disease caused by Colletotrichum cucumeris, which occurs in all watermelon production areas in my country. It can harm the leaves, petioles, vines, stalks and fruits of watermelons, affecting the normal growth and yield of watermelons. Chemical agents are the main measure to control the occurrence of watermelon anthracnose. Commonly used fungicides include: difenoconazole, mancozeb, zinc folate and azoxystrobin. However, due to the irrational application of traditional chemical agents, problems such as pesticide residues and resistance risks are increasing year by year. Therefore, it is necessary to develop new control agents.

[0003] Polygonum cuspidatum extract is extracted from the herbaceous plant Polygonum cuspidatum. It interferes with the biosynthesis of chitin in the cell wall of pathogenic fungi, inhibits the formation of fungal hyphae and haustoria, and the production of spores, thereby blocking the spread of diseases and achieving a bactericidal effect. It is used to prevent and control strawberry powdery mildew, gray mold and other diseases.

[0004] Matrine is an alkaloid extracted from the Chinese herbal medicine Sophora flavescens, which has multiple functions of insecticide, bactericidal and plant growth promotion. Matrine can destroy the cell wall and cell membrane of microorganisms, resulting in increased permeability of cell membranes, leakage of intracellular substances, and ultimately inactivation and death of cells. Matrine can be used in agriculture to prevent and control pests and diseases such as cabbage worms and aphids, cowpea thrips, citrus red spiders, tea tree tea leafhoppers, and pear tree black spot.

[0005] Compounding different pesticides to select synergistic combinations can reduce the impact on the environment and delay the development of drug resistance in pathogens. It is an economical and effective means of preventing and controlling diseases and developing new agents. There are no reports on compounding Polygonum cuspidatum extract and matrine. Summary of the invention

[0006] The object of the present invention is to provide a bactericidal composition for preventing and controlling watermelon anthracnose, which has a synergistic effect on melon anthracnose bacteria, can improve the control effect on watermelon anthracnose, and provide support for the development of new control agents.

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

[0008] A bactericidal composition for preventing and controlling watermelon anthracnose, wherein the effective components are compounded from a knotweed extract and matrine, and the mass ratio of the knotweed extract to matrine is 1:2-5:1.

[0009] Preferably, the mass ratio of the knotweed extract to matrine is 2:1.

[0010] The present invention also provides a fungicide, comprising the fungicide composition for preventing and controlling watermelon anthracnose and auxiliary components, wherein the auxiliary components are selected from one or more of a dispersant, a wetting agent, a defoaming agent, a thickener, an antifreeze agent, a preservative, and deionized water.

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

[0012] (1) After the polygonum cuspidatum extract and matrine are compounded in the fungicide composition of the present invention, they show a synergistic effect on melon anthracnose bacteria, can improve the control effect of watermelon anthracnose, can reduce the amount of pesticide application, and are beneficial to reducing pesticide residues.

[0013] (2) The compounding of the polygonum cuspidatum extract and matrine in the fungicidal composition of the present invention can delay the development of drug resistance of pathogenic bacteria. DETAILED DESCRIPTION

[0014] The present invention can be better understood according to the following examples. However, it is easy for those skilled in the art to understand that the contents described in the examples are only used to illustrate the present invention, and should not and will not limit the present invention described in detail in the claims.

[0015] Example: Indoor activity test of an agricultural composition for preventing and controlling watermelon anthracnose against melon anthracnose

[0016] 1. Test pathogens, test crops, test drugs

[0017] Test pathogens:

[0018] Watermelon plants showing anthracnose were collected from Longchi Town, Pucheng County, Weinan City, Shaanxi Province, and separated and purified in the laboratory. The pathogen was identified as Colletotricum orbiculare and stored on PDA culture medium.

[0019] Tested crops:

[0020] "Green Emperor" watermelon seedlings grown in pots at the 2-4 true leaf stage.

[0021] Test reagents:

[0022] Polygonum cuspidatum extract: Take the rhizome of Polygonum cuspidatum, dry it and crush it. Use 10 times the amount of 70% ethanol to reflux in a 50℃ water bath for 4 hours, filter it, recover ethanol from the filtrate, evaporate the residual liquid to dryness in a water bath, dry the residue at 105℃ for 3 hours, and grind it into powder to obtain the Polygonum cuspidatum extract.

[0023] Matrine: Specification, 10% stock drug, purchased from Inner Mongolia Zhongnong Biochemical Technology Co., Ltd.

[0024] 2. Preparation of Spore Suspension

[0025] The above-mentioned pathogenic bacteria were cultured on a suitable culture medium. After spores were produced, the spores were washed with sterile water and filtered through 2-4 layers of gauze to prepare a 1×10 5 The suspension with spores / mL is used for later use.

[0026] 3. Drug preparation and processing

[0027] The above-mentioned test agents were first dissolved in acetone, and then diluted with 0.1% Tween 80 aqueous solution to form a single-dose stock solution. Multiple groups of proportions were set, and each single dose and proportioned mixture was set with 5 mass concentration gradients according to the equal ratio method.

[0028] Spray the liquid medicine evenly on the leaves until they are completely wet, and wait for the liquid medicine to dry naturally for later use. Treat 3 pots per time, repeat 4 times, and set up a control treatment without active ingredients.

[0029] 4. Inoculation

[0030] 24 hours after the treatment, inoculate with a microsampler to draw 10uL of the above spore suspension and inoculate on the front of the leaves, with 3 inoculation points per pot. After inoculation, move to a moisturizing box with a humidity of 95% and a temperature of 25°C for dark culture for 24 hours, and then culture at a humidity of 80%, a temperature of 25°C, and a light intensity of 20,000Lux.

[0031] 5. Survey

[0032] When the incidence rate of the blank control reached more than 50%, the diameter of the lesion was measured once with a vernier caliper using the cross-cross vertical method and the average value was taken.

[0033] 6. Calculation and analysis

[0034] Control effect, % = (blank control lesion diameter - drug treatment lesion diameter) × 100 / blank control lesion diameter

[0035] DPS software was used for data statistical analysis. The logarithmic value of the drug concentration was taken as x and the corresponding probability value of protection efficiency was taken as y for linear regression to calculate the EC of each drug. 50 The calculation results are shown in Table 1.

[0036] EC 50exp =(a+b) / [(a / EC 50a )+(b / EC 50b )]

[0037] SR=EC 50exp / EC 50实际

[0038] In the formula, a is the percentage of the Polygonum cuspidatum extract in the mixture, b is the percentage of matrine in the mixture, and EC 50ais the inhibitory concentration of Polygonum cuspidatum extract (a) when used alone, EC 50b It is the inhibitory concentration of matrine (b) when used alone. SR ≥ 1.5 indicates synergistic effect, SR ≤ 0.5 indicates antagonistic effect, and 0.5 < SR < 1.5 indicates additive effect.

[0039] Table 1: Results of indoor activity test of agricultural compositions against Colletotrichum cucurbitae

[0040]

[0041] As shown in Table 1, when the mass ratio of Polygonum cuspidatum extract and matrine is in the range of 1:2 to 5:1, it has an excellent inhibitory effect on cucurbit anthracnose, and the SR is greater than 1.5, showing a synergistic effect. Especially when the mass ratio of Polygonum cuspidatum extract and matrine is 2:1, the SR is 2.54, and the synergistic effect is optimal.

[0042] This shows that the combination of Polygonum cuspidatum extract and matrine in a specific ratio shows a synergistic effect on melon anthracnose, can improve the prevention and control effect of watermelon anthracnose, reduce the application dosage of pesticides, and is conducive to reducing pesticide residues.

[0043] The present invention has been described in detail above by general description and specific embodiments, but it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A bactericidal composition for preventing and controlling watermelon anthracnose, wherein the active ingredient is a compound of a knotweed extract and matrine, and the mass ratio of the knotweed extract to matrine is 1:2 to 5:

1.

2. A bactericidal composition for preventing and controlling watermelon anthracnose according to claim 1, characterized in that: The mass ratio of the knotweed extract to matrine is 2:1.

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