Sterilizing or antibacterial agent and use method thereof

Abstract

The present invention relates to agriculture, more particularly to plant cultivation, and relates to a bactericidal or antibacterial agent based on copper and thiourea or derivatives thereof, the invention also relates to the application of the preparation in the planting process of spring-sown and winter-sown cereal and legume crops, open field and protected field vegetable crops, woody shrub crops, fruit tree crops, berry crops, perfume crops, horticultural crops, ornamental crops, melon crops, intertillage crops, economic crops and feed crops. The bactericidal or antibacterial agent comprises a complex of copper (I) with thiourea or methyl thiourea, or N, N '-dimethyl thiourea, or ethyl thiourea, or N, N'-diethyl thiourea, or ethylene thiourea, or N, N '-bis (dimethylaminomethyl) thiourea.

Description

Technical Field

[0001] The present invention relates to the field of agriculture, in particular to the field of plant cultivation, and relates to a bactericidal or antibacterial agent based on copper and thiourea or their derivatives, and their application in the planting of spring-sown and wintering cereal crops, legume crops, open-field and protected vegetable crops, arbor and shrub plants, fruit trees, berry plants, oil crops, horticultural crops, ornamental plants, melon crops, row crops, cash crops and feed crops. The present invention can be used for seed pre-sowing treatment, as well as seedling treatment during greenhouse planting, home gardening, park greening, and farm planting. It is also suitable for plant cultivation and regional greening projects in agricultural complexes, forest nurseries, forest farms, botanical gardens and other places. Background Art

[0002] In agriculture, the large-scale and intensive use of fungicides and their mixtures leads to a certain degree of inhibition of the growth rate and development process of cultivated plants, which not only has a negative impact on crop yields (especially under conditions of water scarcity and climate warming), but also reduces the quality of agricultural products.

[0003] Therefore, during the cultivation of cultivated plants, the intensity of fungicide application during seed treatment and crop sowing must be reduced.

[0004] The fungicides widely known in the prior art include: dithiocarbamate fungicides, such as mancozeb as a mixed salt

[0005]

[0006] Wherein, X: is Zn and Mn; benzimidazole fungicides, such as benomyl, thiabendazole, fuberidazole, carbendazim; triazole derivative fungicides, such as triadimefon, triadimenol, diclobutrazol, flutrimazole, fluazinam, etaconazole, propiconazole, butrizol; imidazole derivative fungicides, such as imazalil and prochloraz); phosphoric acid and thiophosphate / amide fungicides; amine / amidine / guanidine fungicides (such as polyhexamethylene guanidine salts. In addition, compounds of other chemical structure categories are also widely used in the preparation of fungicides.

[0007] As an alternative to organic synthetic substances, copper (II) compound-based fungicides are also widely used in agriculture. These substances have the characteristics of relatively low production cost and simple production process, and can inhibit the growth of a variety of plant pathogenic microorganisms including fungal and bacterial pathogens.

[0008] The first copper-based insoluble antimicrobial compound widely used in agriculture was Bordeaux mixture (a mixture of copper sulfate and lime milk). Other copper compounds such as copper hydroxide, copper carbonate, and copper oxychloride were subsequently used. Copper compounds have three major characteristics: high efficiency, low resistance of plant pathogens, and low toxicity to plant and mammalian cells.

[0009] A more efficient fungicide is a copper complex. For example, Russian Federation Patent No. 2536404 discloses the use of [N,N'-bis(dimethylaminomethyl)thiourea oxalate] copper sulfate pentahydrate as a plant fungal disease control agent.

[0010] Because it easily combines with clay minerals and humus components, copper does not exist in a dissolved state after entering the soil. However, the amount of copper removed from the soil by leaching, rainwater erosion or plant absorption is negligible, so copper will continue to accumulate in the environment (especially within the top 15 cm of the soil) and trigger a biodegradation effect. The continuous use of high-concentration copper compounds for more than a century has led to the accumulation of copper in agricultural soils reaching 40-50 times the copper content of native soils without agricultural cultivation. In view of this, the use of copper compounds in agriculture is being strictly restricted. In view of this, it is of great significance to develop new copper preparations that can maintain antibacterial and bactericidal efficacy at lower metal concentrations.

[0011] One strategy to improve the efficacy of copper compounds is to reduce the particle size of the active ingredient, because smaller particles can improve coverage uniformity, distribution uniformity and adhesion strength, and enhance the stability of the formulation against loss. In addition, such particles have a higher specific surface area (surface area-to-volume ratio), which can accelerate the active Cu 2+ However, the application of this method is limited by technical bottlenecks, and it is impossible to economically and efficiently prepare particles with a diameter of less than 1 micron and aggregation stability.

[0012] Another approach to improving the performance of copper-based fungicides is to find more active chemical forms of the metal, such as copper (I) compounds. 2For example, this ingredient (content 860 g / kg) is the main active ingredient of the commercial fungicide NORDOX 75WG of the Norwegian Nordox company. The defect of this preparation is that the copper oxide particle size is too large, resulting in reduced efficacy.

[0013] Therefore, there is an urgent need to develop more efficient copper-based bactericidal or antibacterial agents.

[0014] The technical effects are achieved by using a bactericidal or antimicrobial agent and a method of using the same as described in detail below. Summary of the invention

[0015] Through experimental studies on the biological activities of different copper (I) complexes, it was found that Cu + The complexes formed with thiourea and its derivatives have the following characteristics: high bactericidal and antibacterial activity; chemical stability that meets the requirements of agricultural applications; low phytotoxicity.

[0016] It can be concluded that the above preparations can be used as fungicides and antibacterial agents in the field of crop cultivation.

[0017] The invention relates to a bactericidal or antibacterial agent, which is suitable for planting crops, including spring-sown and winter-sown cereal and bean crops, open-field and protected-field vegetable crops, woody shrub crops, fruit tree crops, berry crops, spice crops, horticultural crops, ornamental crops, melon crops, row-cultivated crops, economic crops and fodder crops.

[0018] The present invention relates to a bactericidal or antimicrobial agent, which comprises at least one complex of copper (I) and the following substances: a complex of thiourea or methylthiourea, or N,N'-dimethylthiourea, or ethylthiourea, or N,N'-diethylthiourea, or ethylenethiourea, or N,N'-bis(dimethylaminomethyl)thiourea.

[0019] The present invention also relates to a method for using the bactericidal or antibacterial agent in the planting of the following crops: spring-sown and winter-sown cereal and bean crops, open-field and protected-field vegetable crops, woody shrub crops, fruit tree crops, berry crops, spice crops, horticultural crops, ornamental crops, melon crops, row-cultivated crops, economic crops and fodder crops.

[0020] The invention relates to a method for using a bactericidal or antibacterial agent in plant planting, which is characterized in that a solution containing the preparation is used to treat plant seeds or plant vegetative bodies.

[0021] The invention is illustrated by means of several alternative embodiment examples. Example 1

[0022] As a bactericidal or antimicrobial agent, copper(I) formate [CuETU], a complex of copper(I) and ethylenethiourea (ETU), is used. 2 ] + HCOO - preparation.

[0023] The preparation method of the preparation is as follows: weigh and grind copper carbonate into a reaction flask equipped with a stirrer and a thermometer, and add an appropriate amount of room temperature distilled water. Stir the mixture for 10 minutes to form an aqueous suspension. During the continuous stirring process, a solution containing the metered proportion components is sequentially added to the suspension through a dropping funnel: a complexing agent ethylene thiourea, a reducing agent ascorbic acid (C 6 H 8 O 6 ) and formic acid (HCOOH). The reaction mixture was then heated to 60°C and stirred for 2 hours. During the reaction, carbon dioxide gas was observed to be escaping violently. After 2 hours, the suspension was almost completely dissolved and the reaction mixture became transparent. 2 ] + HCOO - The reaction solution was then cooled to room temperature, stirred for 30 minutes and filtered. The filtrate was used as a bactericidal or antibacterial agent.

[0024] The bactericidal and fungicidal activities of the preparation against the following plant pathogenic microorganisms were studied in vitro: Erwinia atroseptica, Sclerotinia sclerotiorum and Fusarium equiseti strain UgLaTF7. The above microorganisms cause plant bacterial fire blight, sclerotinia and root rot, respectively. In addition, the microbiological activity of the preparation was compared with two similar products on the market: 1) "Kocide 2000" (a copper-based fungicide "Kocid 2000" produced by DuPont, USA, with the active ingredient being copper hydroxide); 2) "Zerox" (a silver-based fungicide "Zerox" produced by AgroHimProm, Russia, with the active ingredient being colloidal silver).

[0025] The bactericidal effect against Erwinia atroseptica was determined by the colony forming unit (CFU) counting method. The specific steps are as follows: After the bacteria are cultured on LB agar medium at a temperature of 28°C for 24 hours, they are eluted with sterile water and diluted to a concentration of 1 / 1 or 1 / 500. The diluted bacterial suspension is transferred to a test tube, and the test preparation is added to the final concentration of: copper-based active ingredients 2, 20, 200, 600ppm, silver-based active ingredients 0.2, 2, 20, 60ppm, and allowed to stand for 30 minutes. Sterile water equal to the volume of the bactericide is added to the control group test tube. After incubation, 50 ml of the suspension is remixed and evenly applied to the surface of the agar medium with a sterile coating rod. The number of colonies is counted after culturing at 28°C for 72 hours.

[0026] The bactericidal effect against Sclerotinia sclerotiorum and Fusarium equiseti UgLaTF7 strain was evaluated by plate assay. The specific method is: calculate the percentage of the radial growth of the mycelium of the pathogen on the pea agar medium containing the drug relative to the growth of the control medium without the bactericide (100% means no bactericidal effect, 0% means complete inhibition of the growth of the pathogen). A mycelial agar block with a diameter of 5 mm was placed in the center of the culture dish and then cultured under natural light conditions at 23-25°C. The measurement was performed when the colony diameter of the control group reached 0.5-0.75 times the diameter of the culture dish. Four concentration gradients were set for the test (copper-based active ingredients 2, 20, 60, 200 ppm; silver-based active ingredients 0.2, 2, 6, 20 ppm), and each concentration gradient was repeated twice. At the same time, the effective concentration index ECso value of each bactericide was determined (the effective concentration that reduces the radial growth rate of the pathogen colony by 50% compared with the control group).

[0027] Laboratory test results (Table 1-4) show that: [CuETU 2 ] + HCOO - Even if the preparation does not exceed 60ppm (parts per million, 1ppm = 10 -4 %) can also inhibit the growth of all three tested pathogens. The bactericidal effective concentration of this preparation is significantly lower than that of the similar commercially available copper hydroxide preparation "Keshade 2000". The bactericidal activity data show that among the three tested preparations, only [CuETU 2 ] + HCOO- can inhibit the growth of Fusarium equiseti UgLaTF7 strain within an agriculturally applicable concentration range. Experimental data confirm that the formulation exhibits significant antibacterial activity against both bacterial and fungal plant pathogens at low active ingredient concentrations.

[0028] Table 1. Under the condition of 1:1 dilution of bacterial suspension, [CuETU 2 ] + HCOO - Comparison table of bactericidal activity (CFU) of the preparation and similar products on the market against Erwinia atroseptica

[0029]

[0030]

[0031] Table 2. [CuETU 2 ] + HCOO - Comparison table of bactericidal activity (CFU) of the preparation and similar products on the market against Erwinia atroseptica

[0032]

[0033] Table 3 [CuETU 2 ] + HCOO - Comparison table of fungicidal activity of the preparation and similar products on the market against Sclerotinia sclerotiorum (colony diameter ratio, experimental group / control group)

[0034]

[0035] Table 4 [CuETU 2 ] + HCOO - Comparison table of fungicidal activity of the preparation and similar products on the market against Fusarium equiseti UgLaTF7 strain (colony diameter ratio, experimental group / control group)

[0036]

[0037] Example Group 1

[0038] In Example Group 1, as a bactericidal or antibacterial agent, a complex formed by copper (I) and the following ligands: thiourea or methylthiourea, or N, N'-dimethylthiourea, or ethylthiourea, or N, N'-diethylthiourea, or ethylenethiourea, or N, N'-bis (dimethylaminomethyl) thiourea; the corresponding counter ion is formate, acetate, citrate or phosphite. The preparation method of the preparation is the same as that of Example 1. The preparation and testing methods of the preparation are the same as those of Example 1.

[0039] Experimental data confirmed that: under all test conditions, the inhibitory efficacy of the obtained preparation on the tested strains was significantly better than similar commercially available products, thereby proving that the present invention successfully achieved the technical effect.

Claims

1. A bactericidal or antimicrobial agent, It is characterized in that The bactericidal or antimicrobial agent comprises at least one copper (I) complex with thiourea or methylthiourea, or N,N'-dimethylthiourea, or ethylthiourea, or N,N'-diethylthiourea, or ethylenethiourea, or N,N'-bis (dimethylaminomethyl) thiourea.

2. The bactericidal or antibacterial agent according to claim 1, It is characterized in that The bactericide or antibacterial agent is suitable for crop planting, including spring-sown and winter-sown cereals and legumes, open-field and protected-field vegetable crops, woody shrub crops, fruit tree crops, berry crops, spice crops, horticultural crops, ornamental crops, melon crops, row-cultivated crops, economic crops and fodder crops.

3. A method of using the bactericidal or antimicrobial agent according to claim 1, It is characterized in that During the plant planting process, plant seeds or plant vegetative bodies are treated with a solution containing the preparation according to claim 1.

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