A pesticide fungicide containing d-limonene and its application

Abstract

The present application provides a pesticide bactericide containing d-limonene, the active ingredient of the pesticide bactericide is d-limonene and copper oxide, and the mass ratio of d-limonene and copper oxide is 7-27:20-44. The present application selects d-limonene and copper oxide for compounding, and the two can produce a synergistic effect, thereby making the prepared pesticide bactericide have good bacteriostatic and bactericidal effects, and have a larger control spectrum, especially for wheat basal stem rot. And the test crop wheat is safe, and no phytotoxicity symptoms are found.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and in particular to a pesticide fungicide containing d-limonene and its application. Background Technology

[0002] Wheat stem rot is caused by Fusarium (… Fusarium Wheat stem rot, a global wheat root disease caused by *Fusarium graminearum*, has seen a rapid increase in its affected area in major wheat-growing regions of my country in recent years, influenced by climate conditions and farming practices. *Fusarium graminearum* is one of the pathogens causing this disease. Fusarium pseudogramineum This disease, known as *Trichoderma rotum*, is the dominant pathogen causing wheat stem rot in many regions of my country. Since 2016, it has caused continuous outbreaks in the Huang-Huai wheat-growing area and has become one of the most important diseases affecting wheat production in my country. Typical field symptoms include browning of the wheat leaf sheath or stem base, resulting in "white ears" or shriveled and empty grains. It can occur at any stage of wheat growth. During the seedling stage, it causes yellowing, withering, and seedling death; during the grain-filling stage, it leads to withered white ears. Wheat with white ears exhibits significantly stunted stems, and in severe cases, red or white mold may appear on the affected nodes and internodes. This disease causes significant economic losses annually, making its control extremely important.

[0003] Currently, there are no registered fungicides in my country for controlling wheat stem rot. The fungicides actually used mainly include benzimidazole fungicides such as carbendazim, and sterol demethylation inhibitor fungicides such as prothioconazole, tebuconazole, and fludioxonil. These are all conventional chemical agents that have been used for many years, and wheat has developed high resistance to them, making their effectiveness unreliable and causing significant environmental impact. The 14th Five-Year Plan requires pesticides to be low-toxicity, environmentally friendly, and highly effective. In actual production, there is an urgent need to find pesticide products with minimal environmental impact, wide availability, and reasonable prices for controlling wheat stem rot.

[0004] Limonene is primarily derived from natural plant extracts, such as the peels of citrus fruits like oranges and lemons. Limonene itself is insoluble in water and possesses strong degreasing and stain-removing abilities. Its applications in the cleaning industry are very broad, including as adhesive removers, asbestos tile removers, bathroom cleaners, and carpet stain removers. In addition, limonene also has certain insecticidal, antibacterial, and anti-inflammatory properties. Its effect on pathogens is to dehydrate and dry the phospholipid bilayer of pathogens, thus achieving a bactericidal effect. Limonene belongs to the monoterpenoid class of compounds and has three isomers: D-limonene, L-limonene, and DL-limonene. D-limonene is chemically more reactive and exhibits good insecticidal efficacy against agricultural pests of Lepidoptera, Hemiptera, Coleoptera, and Hymenoptera. It also has a certain inhibitory effect on fungal and bacterial diseases that easily infect plants, making it a safe and environmentally friendly antibacterial substance.

[0005] Copper chloride, also known as basic copper chloride, has the molecular formula Cu2(OH)3Cl and a molecular weight of 213.56. It is a natural copper-containing inorganic fungicide and is considered the least phytotoxic among copper-based fungicides. After application, it rapidly destroys pathogenic proteases, causing pathogen death, and forms a protective film on the plant surface. It is not easily washed away by rainwater and has a growth-stimulating and yield-increasing effect. It adheres strongly to plants and releases copper ions stably and slowly, generally causing little phytotoxicity to crops, and pathogens are less likely to develop resistance. It stimulates growth and increases yield in crops such as potatoes, peanuts, and sunflowers. It can also be used to control apple spot, leaf drop, and brown spot; pear scab; and grape downy mildew, powdery mildew, and black rot.

[0006] Neither d-limonene nor copper oxychloride has been used in wheat, and there are currently no reports on their combination for controlling wheat stem rot. Therefore, exploring the application of their combination in wheat stem rot has high innovation and practical application value. Summary of the Invention

[0007] To address the technical problems existing in the background art, this application proposes a pesticide fungicide containing d-limonene and copper oxychloride, as well as its uses.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A pesticide fungicide containing d-limonene, wherein the active ingredients of the pesticide fungicide are d-limonene and copper hydroxide, and the mass ratio of d-limonene to copper hydroxide is 7-27:20-44.

[0010] As a preferred technical solution, the mass ratio of d-limonene to copper oxychloride is 17:32.

[0011] As a preferred technical solution, the mass of d-limonene accounts for 3.5-13.5% of the mass of the pesticide fungicide; and the mass of copper oxychloride accounts for 10-22% of the mass of the pesticide fungicide.

[0012] As a preferred technical solution, the mass of d-limonene accounts for 8.5% of the mass of the pesticide fungicide; and the mass of copper oxychloride accounts for 16% of the mass of the pesticide fungicide.

[0013] As a preferred technical solution, the pesticide fungicide is in the form of a liquid preparation, such as an aqueous solution, an emulsion, a suspension, or a suspension emulsion.

[0014] Preferably, the pesticide fungicide is in the form of a suspension seed coating agent.

[0015] The suspension seed coating agent is composed of the following substances by mass percentage: 3.5-13.5% d-limonene, 10-22% copper oxychloride, 1-8% dispersant, 1-10% wetting agent, 0.1-2% thickener, 1-6% preservative, 1-5% antifreeze, 1-3% film-forming agent, 1-3% pigment, and the balance being water.

[0016] The second objective of this invention is to provide the use of the above-mentioned pesticide fungicide for the prevention and control of wheat stem rot.

[0017] This invention selects d-limonene and copper oxychloride to form a compound, which can produce a synergistic effect, thereby making the prepared pesticide fungicide have good antibacterial and fungicidal effects, and a wide spectrum of control, especially with good control effect on wheat stem base rot. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0019] This invention provides a pesticide fungicide, the active ingredient of which is composed of d-limonene and copper hydroxide. The dispersants provided in this invention include, but are not limited to, existing dispersants such as sodium lignosulfonate, Tween-80, and Span-80; the wetting agents include, but are not limited to, existing surfactants such as sodium dodecyl sulfate, alkylnaphthalene sulfonate, alkylbenzene sulfonate, and fatty acid polyoxyethylene ether; the thickeners include, but are not limited to, existing thickeners such as xanthan gum and carboxymethyl cellulose; the preservatives include, but are not limited to, existing preservatives such as sodium benzoate and formaldehyde; and the antifreeze agents include, but are not limited to, existing antifreeze agents such as ethylene glycol and polyvinyl alcohol. The film-forming agents include, but are not limited to, polyvinyl alcohol, polyethylene glycol, gelatin, gum arabic, xanthan gum, and high molecular weight organic compounds.

[0020] It should be noted that the fungicide provided by this invention is used to prevent and control crop diseases, including but not limited to wheat stem rot, but this pesticide fungicide has a better effect on preventing and controlling wheat stem rot.

[0021] Furthermore, this pesticide fungicide affects the normal growth of plants. This pesticide fungicide is a liquid formulation, preferably a suspension concentrate. It should be noted that the embodiments of this invention only list suspension concentrates; however, it is understood that other types of liquid formulations are also within the scope of protection of these embodiments.

[0022] The preparation method of the suspension seed coating agent is as follows: Calculate the amount of each material to be added according to the product composition. In an enamel-lined kettle, add the active ingredients (d-limonene, copper oxychloride), dispersant, wetting agent, thickener, preservative, antifreeze agent, film-forming agent, and pigment in sequence, and then add water to make up the balance. Perform one cycle of high-speed shearing in an external circulation system to ensure that there are no large particles in the mixing kettle after grinding. After shearing, the material enters a sand mill for sand milling until more than 90% of the particles have a diameter of less than 5 micrometers. After sand milling, the material enters a post-mixing kettle and is stirred until homogeneous to obtain the product.

[0023] Suspension seed coating agents are formulated by coating a suspension of the agent onto the surface of seeds, forming a uniform coating to control pests and diseases. Suspension seed coating agents offer advantages such as ease of use, good control efficacy, and reduced pesticide consumption.

[0024] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0025] Example 1

[0026] This embodiment provides a fungicide suspension seed coating agent, the composition of which is shown in the table below by mass percentage:

[0027] Table 1. Dosage ratio of each component in the bactericidal composition

[0028]

[0029] Example 2

[0030] This embodiment provides a bactericidal composition, the components of which are shown in the table below by weight percentage:

[0031] Table 2. Dosage ratio of each component in the bactericidal composition.

[0032]

[0033] Example 3

[0034] This embodiment provides a bactericidal composition, the components of which are shown in the table below by weight percentage:

[0035] Table 3. Dosage ratio of each component in the bactericidal composition.

[0036]

[0037] Example 4

[0038] This embodiment provides a bactericidal composition, the components of which are shown in the table below by weight percentage:

[0039] Table 4. Dosage ratio of each component in the bactericidal composition

[0040]

[0041] Example 5

[0042] This embodiment provides a bactericidal composition, the components of which are shown in the table below by weight percentage:

[0043] Table 5. Dosage ratio of each component in the bactericidal composition

[0044]

[0045] Comparative Example 1

[0046] This embodiment provides a bactericidal composition, the components of which are shown in the table below by weight percentage:

[0047] Table 6. Dosage ratio of each component in the bactericidal composition.

[0048]

[0049] Comparative Example 2

[0050] This embodiment provides a bactericidal composition, the components of which are shown in the table below by weight percentage:

[0051] Table 7. Dosage ratio of each component in the bactericidal composition.

[0052]

[0053] Experiment Example 1: Bioactivity Test

[0054] According to the guidelines for indoor bioassay of pesticides NY / T 1156.12-2008 and NY / T1156.6-2006, the effects of d-limonene, copper oxychloride, and their different mass ratios on wheat stem base rot were determined, and the optimal mixing mass ratio of these two fungicides was screened.

[0055] Fusarium graminearum ( Fusarium pseudogramineum The reagents were isolated and preserved by the bioassay laboratory of Anhui Fengle Agricultural Chemical Co., Ltd.; the test reagents were d-limonene and copper hydroxide technical; the mixed mass ratio of d-limonene to copper hydroxide was 7:44; 6:19; 17:32; 11:13; 27:20; the prepared concentrations are shown in Table 8.

[0056] Table 8. Dosage ratio of each substance in the bactericidal composition

[0057]

[0058] Under aseptic conditions, pre-melted sterile culture medium was quantitatively added to sterile Erlenmeyer flasks according to the experimental treatment. Quantitative amounts of the drug solution were sequentially added to the Erlenmeyer flasks from low to high concentration, and the mixture was thoroughly shaken. Then, equal volumes were poured into four 9cm diameter petri dishes to prepare drug-containing plates of the corresponding concentrations. After sporangia were generated, the sporangia were washed off with sterile water, filtered through double-layered gauze, and placed in the dark at 4°C for 3 hours to release zoospores, which were then directly prepared into a spore solution for use.

[0059] 24 hours before the experimental treatment, the spores were inoculated with a spore suspension. After inoculation, the spores were subjected to continuous light / dark cycles for 12 hours daily at room temperature and 90% relative humidity for 7 days. The experiment consisted of seven treatments, with a 0.1% Tween 80 aqueous solution containing an equal volume of acetone serving as a blank control. The solution was sprayed evenly onto the leaf surface until completely wet, and allowed to air dry naturally before use. Each treatment was replicated four times.

[0060] After the blank control reached 50%, the mycelial growth of each treatment was investigated at different levels. Based on the investigation results, the control effect of each treatment concentration was calculated according to formula (1), with the unit being percentage (%). The calculation results were retained to two decimal places.

[0061] (1)

[0062] In the formula:

[0063] I—Prevention and control effect;

[0064] D0—Disease index of blank control;

[0065] D t —Drug treatment disease index.

[0066] Statistical analysis

[0067] Regression analysis was performed based on the logarithmic values ​​of each drug concentration and the corresponding disease index to calculate the EC50 of each drug. 50 EC 90 and 95% confidence limit.

[0068] The synergistic effect coefficient (SR) of the mixture is calculated using the Wadley method to evaluate the type of combined action of the mixture. The synergistic effect of drug mixtures is evaluated based on the synergistic effect coefficient (SR), i.e., SR < 0.5 indicates antagonism, 0.5 ≤ SR ≤ 1.5 indicates additive action, and SR > 1.5 indicates synergistic effect. The synergistic effect coefficient (SR) is calculated according to equations (2) and (3):

[0069] (2)

[0070] In the formula:

[0071] X1—Mixed Agent EC 50Theoretical value, in milligrams per liter (mg / L);

[0072] P A —The percentage content of A in the mixture;

[0073] P B —Percentage content of B in the mixture;

[0074] A—EC of A in the mixture 50 Value, in milligrams per liter (mg / L);

[0075] B—EC of B in the mixture 50 Value, in milligrams per liter (mg / L).

[0076] (3)

[0077] In the formula:

[0078] SR—synergistic effect coefficient of the mixture;

[0079] X1—Mixed Agent EC 50 Theoretical value, in milligrams per liter (mg / L);

[0080] X2—Mixed Agent EC 50 Measured values, in milligrams per liter (mg / L).

[0081] The test results are shown in Table 9 below:

[0082] Table 9 Test Results

[0083]

[0084] The results above indicate that d-limonene, copper hydroxide, and their various mixtures all exhibit significant fungicidal effects against wheat stem rot. The mixtures of d-limonene and copper hydroxide showed synergistic effects at the experimental ratios, with the highest synergistic effect observed at a ratio of 17:32 (d-limonene:copper hydroxide), with a synergistic coefficient of 7.12. 50 0.1612 mg / L, LC 90 It is 1.02306 mg / L.

[0085] Experimental Example 2: Field Efficacy Trial

[0086] Field efficacy trial 1: The test agents were Examples 1-5, Comparative Examples 1-2, and the conventional chemical agent 15% Mancozeb suspension seed coating agent (8% carbendazim + 7% thiram) as Comparative Example 3 (all produced by Anhui Fengle Agricultural Chemical Co., Ltd.). These agents were mixed evenly with wheat seeds according to the agent-to-seed ratio, forming a uniform coating layer on the surface of the wheat seeds, ready for sowing. Test methods: The test agents are shown in Table 10 below:

[0087] Table 10. Test dosage of each drug.

[0088]

[0089] The experimental site was located in Hongdian Village, Gaoliu Town, Hefei City, Anhui Province, at 31.96°N, 116.91°E. The soil type was loam, with an organic matter content of 1.57% and a pH of 7.1.

[0090] The target of the experiment was wheat stem rot, and the application method was seed coating before sowing. The experimental field had a moderate incidence of the disease throughout the year.

[0091] Experimental crop: wheat, variety: Zhenmai 16. Seeds were coated on November 13th and sown on November 14th at a rate of 20 kg / mu. Cultivation conditions, including wheat variety, sowing rate, sowing time, field density, and fertilizer and water management, were consistent across all plots. The wheat grew uniformly. The previous crop in the experimental fields was rice.

[0092] The experimental site underwent its first rotary tillage on November 10, 2021, and its second rotary tillage on November 12, 2021. 30 kg / mu of N:P:K = 15:15:15 was applied as base fertilizer. On February 17, 2022, 10 kg / mu of urea (N≧46%) was applied as top dressing.

[0093] Before sowing wheat, on November 13th, the seed quantity for each plot was calculated based on the sowing rate (20 kg / mu) and the experimental design. The seeds were coated according to the treatment, and the pesticide solution was prepared according to the amount of water used (2 liters / 100 kg of seeds). The solution was thoroughly mixed with the seeds to ensure even distribution on the seed surface. After drying, the seeds were sown.

[0094] 300 seeds were sown in each plot with a fixed area of ​​1m2. The emergence status was investigated, and the emergence rate and emergence time were recorded. Five points were sampled diagonally in each plot. At each point, double rows of samples were taken for 1m to investigate the disease status at the base of the stem. The investigation was carried out by plant and the total number of plants and the number of diseased plants at each level were recorded.

[0095] Grading method:

[0096] Grade 0: No disease spots at the base of the stem;

[0097] Grade 1: Lesions surround less than 25% of the stem base;

[0098] Grade 3: Lesions surround 26% to 50% of the stem base;

[0099] Grade 5: Lesions surround 51%~75% of the stem base;

[0100] Level 7: Lesions surround more than 76% of the stem base, the plant wilts, and is close to death or dead.

[0101] Methods for calculating drug efficacy

[0102]

[0103]

[0104] The control effects of different pesticides on wheat stem rot are shown in the table below:

[0105] Table 11 Control effects of different pesticide treatments on wheat stem rot

[0106]

[0107] According to the table above, the efficacy survey results show that the formulation dosage (drug-to-mass ratio) of 1:100 in Example 3 has the best control effect, with an efficacy of 86.30%; the emergence rate is highest at 1:100, reaching 88.2%. This is significantly better than the efficacy of the two single-dose control agents and conventional chemical agents. Field observations showed that both the tested and control agents were safe for the experimental wheat crop, and no phytotoxic symptoms (such as dwarfing, chlorosis, or deformity) were observed. This demonstrates that the compound composition of d-limonene and copper oxychloride has good control efficacy against wheat stem rot, a high emergence rate, and good safety, making it a good alternative to conventional chemical agents with high innovation.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The use of a pesticide fungicide, characterized in that: The pesticide fungicide is used to prevent and control wheat stem base rot; the active ingredients of the pesticide fungicide are d-limonene and copper hydroxide, and the mass ratio of d-limonene to copper hydroxide is 7-27:20-44.

2. The pesticide fungicide according to claim 1, characterized in that: The mass ratio of d-limonene to copper oxychloride is 17:

32.

3. The use according to claim 1, characterized in that: The d-limonene accounts for 3.5-13.5% of the total mass of the pesticide fungicide; the copper oxychloride accounts for 10-22% of the total mass of the pesticide fungicide.

4. The use according to claim 3, characterized in that: The d-limonene accounts for 8.5% of the total mass of the pesticide fungicide; the copper hydroxide accounts for 16% of the total mass of the pesticide fungicide.

5. The use according to claim 1, characterized in that: The pesticide fungicide is a liquid formulation.

6. The use according to claim 5, characterized in that: The pesticide fungicide is formulated as a suspension seed coating agent.

7. The use according to claim 6, characterized in that: The suspension seed coating agent is composed of the following substances by mass percentage: 3.5-13.5% d-limonene, 10-22% copper oxychloride, 1-8% dispersant, 1-10% wetting agent, 0.1-2% thickener, 1-6% preservative, 1-5% antifreeze, 1-3% film-forming agent, 1-3% pigment, and the balance being water.

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