Composition for resisting tobacco brown spot

Abstract

The invention belongs to the field of pesticide compositions, and particularly relates to a composition for resisting tobacco brown spot. The active ingredients of the composition are soybean saponin and a composition A, and the composition A is composed of cuaminosulfate and hymexazol according to the mass ratio of 1: 3. The preferable mass ratio of the soybean saponin to the composition A is 0.1: 0.01. Indoor toxicity determination and field test results show that the ternary composition has a remarkable synergistic effect on tobacco alternaria alternata pathogenic bacteria, and the field control effect reaches 93.07% at most and is far superior to the effect of each single agent. According to the invention, by introducing the plant source component soyasaponin, the use amount and the residual risk of chemical pesticides are remarkably reduced while the excellent control effect is ensured, and a brand new solution is provided for green and efficient prevention and control of the tobacco brown spot.

Description

Technical Field

[0001] This invention belongs to the field of pesticide compositions, specifically relating to a composition for resisting tobacco red spot disease. Background Technology

[0002] Tobacco red spot disease, one of the major diseases in tobacco production, seriously affects the development of the tobacco industry. Statistics show that red spot disease leads to incomplete tobacco leaves, lower grade, reduced total sugar and reducing sugar content, an imbalanced sugar-alkali ratio, and a significant decrease in industrial usability. Traditional control methods mainly rely on the breeding of disease-resistant varieties and chemical agents. However, the long-term use of traditional fungicides alone has led to drug resistance in pathogens, and powder formulations are prone to environmental pollution. Therefore, there is an urgent need to develop new, highly efficient, low-toxicity, and environmentally friendly control technologies.

[0003] Copper oxychloride interacts with pathogen cell membranes via cation exchange between copper ions and the membrane proteins, causing membrane protein coagulation. Simultaneously, it penetrates the cell to disrupt enzyme activity, thus exhibiting both protective and therapeutic effects. It demonstrates excellent compatibility; when combined with other components such as cymoxanil and copper citrate, its effectiveness in controlling diseases like Fusarium wilt and downy mildew is significantly enhanced. Studies have shown that copper oxychloride can promote root growth and enhance stress resistance in crops, and it has been widely used in crops such as cucumbers and rice.

[0004] As a systemic fungicide, oxadixyl can be absorbed by plant roots, stems, and leaves, and metabolized into glycosides, activating physiological activity and promoting root tillering and root hair growth. Its unique mechanism of action effectively controls soil-borne diseases such as damping-off and wilt, and also promotes crop growth. When combined with copper oxychloride, the two disrupt the pathogen's structure through different pathways, forming a multi-layered defense of "protection + treatment + systemic action."

[0005] CN101632387A discloses that a mixture of copper oxychloride and oxamyl has a synergistic effect on the prevention and control of tobacco red spot disease within a certain proportion range. However, its use still has technical problems such as relying mainly on chemical bactericidal mechanisms, limited adaptability to pathogen mutations, the potential accumulation of heavy metal pollution with long-term use of copper preparations, and the risk of pathogen resistance.

[0006] Plant-derived components, due to their environmental friendliness and low residue, are gradually becoming important components of traditional chemical pesticides. Soysaponins are a class of small, bioactive components found in soybeans and their products. They belong to the amphiphilic oleanane-type triterpenoid glycosides, with a unique molecular structure consisting of a nonpolar pentacyclic triterpenoid core conjugated with polar sugar chains. This amphiphilic characteristic gives them both surfactant properties and biomembrane penetration capabilities. Studies have reported that soysaponins possess a wide range of beneficial biological activities, including antitumor, antioxidant, hypoglycemic, cholesterol-lowering, hepatoprotective, and immunomodulatory effects.

[0007] There are no reports of using soybean saponins for the control of tobacco red spot disease, let alone reports of using them in combination with copper oxychloride or oxamyl for disease control. Therefore, it is of great research significance to study their combination with other chemical pesticides to reduce the amount of chemical pesticides used. Summary of the Invention

[0008] To address the technical challenges of pesticide resistance and residue risks associated with chemical agents used in the control of tobacco red spot disease, this invention explores the application of plant-derived soybean saponins in the prevention and control of this disease. Through systematic research, it was discovered that a specific ratio of soybean saponins to the chemical agents copper oxychloride and oxadixyl exhibits a significant synergistic effect in controlling tobacco red spot disease. This combination strategy not only significantly improves disease control efficacy but also provides a novel technical approach and solution for the green and efficient control of tobacco red spot disease.

[0009] On one hand, the present invention provides a composition for resisting tobacco red spot disease, wherein the active ingredient of the composition is composed of soybean saponins and composition A, wherein composition A is composed of copper oxychloride and oxamyl.

[0010] Furthermore, in the composition for treating tobacco red star disease, the mass ratio of copper oxychloride to oxamyl in composition A is 1:3.

[0011] Furthermore, in the composition for resisting tobacco red spot disease, the mass ratio of soybean saponin to composition A is 0.01~0.5:0.005~0.5.

[0012] Furthermore, in the composition for resisting tobacco red spot disease, the mass ratio of soybean saponins to composition A is 0.1:0.01.

[0013] Furthermore, the composition for combating tobacco red spot disease is an aqueous solution.

[0014] Secondly, a method for preventing and controlling tobacco red spot disease is also provided, wherein the composition for preventing and controlling tobacco red spot disease described in this invention is applied to tobacco plants.

[0015] Thirdly, the invention also provides the use of the composition for resisting tobacco red spot disease in the preparation of a pesticide, the pesticide comprising the composition for resisting tobacco red spot disease.

[0016] Finally, a pesticide formulation is also provided, comprising the composition for resisting tobacco red spot disease as described in this invention as the active ingredient, and a pesticide-acceptable carrier and adjuvants.

[0017] For example, pesticides containing the aforementioned composition for resisting tobacco red spot disease can be prepared as conventional suspensions. The carriers used include diatomaceous earth, light calcium carbonate, kaolin, silica, and attapulgite; suitable carrier materials are selected based on their antibacterial properties, wetting time, and maximum adsorption capacity. Emulsifiers such as BY (castor oil polyoxyethylene ether) series emulsifiers, Agricultural Emulsion 700# (common name: alkylphenol formaldehyde resin polyoxyethylene ether), Agricultural Emulsion 2201, Span-60 (common name: sorbitan monostearate), Tween-60 (common name: dehydrated sorbitan monostearate polyoxyethylene ether), Agricultural Emulsion 1601 (common name: phenethylphenol polyoxyethylene polyoxypropylene ether), and TERSPERSE 4894 are selected as one or more; wetting agents are selected as one or more of sodium dodecylbenzene sulfonate (SDBS), dispersant, sodium citrate, and monosodium glutamate; dispersants are selected as one or more of sodium dodecyl sulfate (SDS), sodium lignosulfonate, PEG8000, and sodium carboxymethyl cellulose (CMC-Na).

[0018] For example, pesticides containing the aforementioned composition for resisting tobacco red spot disease can be prepared as conventional wettable powders. In this wettable powder, those skilled in the art can select diatomaceous earth, kaolin, light calcium carbonate, talc, silica, attapulgite, clay, etc., as carriers, and sodium lignosulfonate, calcium lignosulfonate, naphthalenesulfonate formaldehyde condensate, methylnaphthalenesulfonate formaldehyde condensate, etc., as dispersants, along with other conventional adjuvants. This ensures that the active ingredient—the composition for resisting tobacco red spot disease—is uniformly dispersed in the carrier and adjuvant system. Upon dilution with water, it can quickly disperse in water to form a stable suspension, facilitating uniform application to the surface of tobacco plants via spraying or other methods, thereby effectively controlling tobacco red spot disease.

[0019] It should be noted that the examples of the above-mentioned formulations and the carriers or adjuvants used are merely illustrative descriptions or exemplary guidance of specific implementation methods of the technical solutions of the present invention.

[0020] Compared with the prior art, the technical solution provided by the present invention has at least the following beneficial effects or advantages: (1) This invention is the first to combine plant-derived active ingredient soybean saponins with chemical fungicides copper oxychloride and oxamyl. Indoor toxicity tests confirmed that the combination of soybean saponins with chemical fungicides copper oxychloride and oxamyl in a specific ratio showed a synergistic effect against the pathogen Alternaria alternata. Field efficacy trials further verified that the control effect of this ternary combination against tobacco scab was as high as 93.07%, which is significantly better than that of a single component, and solved the technical problem that the efficacy of existing chemical agents decreases with the development of drug resistance.

[0021] (2) Soybean saponins themselves have no direct toxic activity against pathogens, but their unique amphiphilic structure can significantly improve the penetration and conduction efficiency of chemical agents. This invention utilizes this characteristic to achieve higher control effects while significantly reducing the effective dosage of chemical pesticides such as copper oxychloride and oxychlorpyrifos, which helps to delay the development of drug resistance in pathogens, reduce pressure on the environment and non-target organisms, and provide a green control technology solution for the prevention and control of tobacco red spot disease. Detailed Implementation

[0022] The technical solution of the present invention will be described below with reference to the embodiments. However, the present invention is not limited to the following embodiments.

[0023] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below with reference to specific embodiments, but the embodiments are not intended to limit the present invention.

[0024] Unless otherwise specified, the experimental and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials are commercially available.

[0025] Soy saponins were purchased from Hebei Qiansheng Biotechnology Co., Ltd., with a purity of 99%.

[0026] The 25% aqueous solution of copper oxychloride was prepared by Beijing Dongwang Pesticide Factory.

[0027] The technical grade of oxadixyl was purchased from Shandong Weifang Tianda Plant Protection Co., Ltd.

[0028] Example 1 This embodiment is an indoor toxicity test of a mixture of soybean saponins with copper oxychloride and oxamyl.

[0029] Test bacteria: Alternaria was provided by Northwest A&F University.

[0030] Preparation of drug-containing culture plates: Soybean saponins and Composition A were dissolved and diluted with water to prepare single-agent stock solutions and stock solutions of various mixed formulations. Composition A was prepared by mixing copper oxychloride and oxamyl at a mass ratio of 1:3. Under aseptic conditions, pre-melted sterile PDA medium was quantitatively added to sterile Erlenmeyer flasks. From low to high concentration, quantitative amounts of the stock solution of soybean saponins and Composition A, soybean saponins alone, and Composition A were sequentially added to the Erlenmeyer flasks and thoroughly mixed. Then, equal volumes were poured into 9cm diameter Petri dishes to prepare culture plates with different concentrations of soybean saponins and Composition A mixtures, soybean saponins alone, and Composition A. These are culture plates with different drug contents. The effective components of each drug are shown in the table below. Each treatment was performed in triplicate. For future use.

[0031] The toxicity of fungicides against Alternaria alterniflora in each experimental group was determined using the mycelial growth inhibition method, and the synergistic effect of the fungicides was determined using the growing method. Under aseptic conditions, cultured Alternaria alterniflora were broken into mycelial cakes using a 0.5 cm diameter punch. These mycelial cakes were then inoculated into the center of a drug-containing culture plate with the mycelial side facing upwards. The plate was covered and incubated at 28°C. A water-based blank control was included. After 48 hours, the results were observed. The diameter of the colonies was measured from three different directions, and the average value was calculated to determine the mycelial growth inhibition rate. The results are shown in Table 1. The determination formula and method are as follows: Mycelial growth inhibition rate = [(Coronavirus diameter in blank control - Coronavirus diameter in drug-treated colonies) / Coronavirus diameter in blank control] × 100% C exp =C1+C2×(1-C1).

[0032] Among them, C exp C1 represents the expected level (theoretical inhibition rate) of the inhibitory effect of soybean saponins on pathogens after being combined with composition A; C2 represents the actual inhibition rate of soybean saponins on pathogens when used alone; C3 represents the actual inhibition rate of composition A on pathogens when used alone. obs The actual inhibition rate of the pathogen by soybean saponins combined with composition A was determined in the experiment.

[0033] If C obs- C exp >10% indicates that the components in the compound preparation exhibit a synergistic effect; If C obs- C exp <-10% indicates that the components in the compound preparation exhibit antagonistic effects; If C obs- C exp A value between -10% and 10% indicates that the components in the compound preparation exhibit an additive effect.

[0034] Table 1. Toxicity test results of compositions containing soybean saponins and composition A against Alternaria alterniflora.

[0035] Table 1 shows that when the concentration of soybean saponins alone is in the range of 0.001 g / L to 1 g / L, the inhibition rate of Alternaria alternifolia is extremely low, fluctuating only between 1.05% and 1.35%. This indicates that under the experimental conditions, soybean saponins alone have no fungicidal activity against Alternaria alternifolia. Composition A (copper oxychloride: oxadixyl = 1:3 by mass) has significant antibacterial activity against Alternaria alternifolia, and the antibacterial activity is dose-dependent. When soybean saponins are combined with Composition A at a mass ratio of 0.01~0.5:0.005~0.5, the inhibition rate of Alternaria alternifolia after combination reaches 70.12%~95.93%. The antibacterial effect of the combination is significantly better than that of the single agent, showing a synergistic effect. In particular, when the mass ratio of soybean saponins to Composition A is 0.1:0.01, the synergistic effect is the best. This combination scheme allows Composition A to achieve a high control effect even with a low dose of chemical pesticides. This provides an important basis for developing low-toxicity, high-efficiency green pesticide formulations.

[0036] Example 2 This example describes the preparation of an aqueous solution of a ternary composition containing soybean saponins and composition A.

[0037] Weigh out 5% soybean saponins, 0.05% of 25% copper oxychloride (final concentration of copper oxychloride is 0.0125%), and 0.0375% oxadixyl according to the following mass percentages, with the remainder being water. Stir and mix well to obtain an aqueous solution of the ternary composition. Prepare immediately before use and label it as 1# ternary composition aqueous solution.

[0038] Example 3 This example describes the preparation of an aqueous solution of a ternary composition containing soybean saponins and composition A.

[0039] Weigh out 1% soybean saponins, 0.1% of 25% copper oxychloride (final concentration of copper oxychloride is 0.025%), and 0.075% oxadixyl according to the following mass percentages, with the remainder being water. Stir and mix well to obtain an aqueous solution of the ternary composition. Prepare immediately before use and label it as 2# ternary composition aqueous solution.

[0040] Example 4 Weigh out 0.5% soybean saponins, 1% 25% copper oxychloride (final concentration of copper oxychloride is 0.25%), and 0.75% oxadixyl according to the following mass percentages, with the remainder being water. Stir and mix well to obtain an aqueous solution of the ternary composition. Prepare immediately before use and label it as 3# ternary composition aqueous solution.

[0041] Example 5 Weigh out 0.1% soybean saponins, 5% of 25% copper oxychloride (final concentration of copper oxychloride is 1.25%), and 3.75% oxadixyl according to the mass percentage, with the remainder being water. Stir and mix well to obtain an aqueous solution of the ternary composition. Prepare immediately before use and label it as 4# ternary composition aqueous solution.

[0042] Example 6 This example is a field efficacy test of a ternary composition containing soybean saponins and composition A.

[0043] Experiment location: Tobacco-growing area of ​​Ankang City, Shaanxi Province.

[0044] Tobacco fields severely affected by Tobacco Red Spot Disease in Ankang City, Shaanxi Province, were selected for treatment starting at the initial appearance of sporadic lesions. The experiment included 13 treatments. The ternary compound aqueous solutions (1# to 4#) prepared in Examples 2-5 served as the test groups. 5% soybean saponin was used as the first control agent (1#), 1% soybean saponin as the second control agent (2#), 0.5% soybean saponin as the third control agent (3#), and 0.1% soybean saponin as the fourth control agent (4#). Composition A, prepared by mixing copper oxychloride and oxadixyl at a mass ratio of 3:1, served as the fifth to eighth control agents (5# to 8#). This composition contained 0.05% (by mass) of 25% copper oxychloride (final concentration of copper oxychloride was 0.0125%) and 0.0375% oxadixyl. The following are contrast agents: Composition A (5#) was prepared by mixing 0.1% (by weight) of 25% copper oxychloride (final concentration 0.025%) and 0.075% oxamyl, with the remainder being water; Composition A (7#) was prepared by mixing 1% (by weight) of 25% copper oxychloride (final concentration 0.25%) and 0.75% oxamyl, with the remainder being water; Composition A (8#) was prepared by mixing 5% (by weight) of 25% copper oxychloride (final concentration 1.25%) and 3.75% oxamyl, with the remainder being water. A water control group was also included. The above experimental and contrast agent groups were diluted 1:300 and sprayed three times consecutively every 5 days, spraying both sides of the leaves each time. Each treatment had four replicates. The final treatment was investigated 10 days after the last application. According to the "Classification and Survey Methods for Tobacco Diseases and Pests" (GBT23222-2008), the survey was conducted at 9 levels, with leaves as the unit. The disease index and control effectiveness were calculated, and the statistical results are shown in Table 2. The calculation formula is as follows:

[0045]

[0046] Table 2. Control efficacy of the ternary combination against tobacco red spot disease.

[0047] Table 2 shows that the combination of soybean saponins and composition A (prepared by mixing copper oxychloride and oxadixyl in a mass ratio of 1:3) exhibited better control efficacy against tobacco red spot disease in the field than soybean saponins alone and composition A itself. This indicates that the combination of soybean saponins and composition A has a synergistic effect. In particular, the combination of soybean saponins and composition A in a mass ratio of 0.1:0.01 achieved a control efficacy of 93.07% against tobacco red spot disease, far exceeding the control efficacy of single agents. This ratio demonstrates the optimal synergistic effect. This ternary composition, by utilizing the synergistic effect of the plant-derived component soybean saponins, significantly reduces the amount of chemical pesticides used while ensuring control efficacy, providing a safe and effective green control solution for tobacco red spot disease.

[0048] As described above, the basic principles, main features, and advantages of the present invention have been well described. The above embodiments and specifications are merely descriptions of preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. Various changes and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit and scope of the present invention should fall within the protection scope defined by the present invention.

Claims

1. A composition for resistance to tobacco brown spot, characterized by, The active ingredient of the composition consists of soyasaponin and a composition A consisting of copper hydroxide and hymexazol.

2. The composition of claim 1, wherein, The mass ratio of copper hydroxide to hymexazol in the composition A is 1:

3.

3. A composition for protection against tobacco brown spot according to claim 1 or 2, characterized in that, The mass ratio of the soyasaponin to the composition A is 0.01-0.5:0.005-0.

5.

4. The composition for controlling tobacco brown spot according to claim 3, characterized by, The mass ratio of the soyasaponin to the composition A is 0.1:0.

01.

5. The composition for controlling tobacco brown spot according to claim 1, characterized by, The composition is an aqueous agent.

6. A method of controlling tobacco brown spot, characterized by, The composition for controlling tobacco brown spot according to any one of claims 1 to 5 is applied to tobacco plants.

7. Use of the composition for controlling tobacco brown spot according to any one of claims 1 to 5 in the production of an agricultural chemical.

8. A pesticidal formulation, characterized by, A composition for controlling tobacco brown spot according to any one of claims 1 to 5 is contained as an active ingredient, and an agriculturally acceptable carrier and adjuvant.

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