A nano-zinc oxide bactericidal composition and application thereof

Abstract

The present application belongs to the field of agricultural fungicides, and particularly relates to a fungicidal composition containing nano-zinc oxide and brucea extract and application thereof, wherein the mass ratio of the nano-zinc oxide and the brucea extract in the active ingredient of the fungicidal composition is 40:1-1:40; the fungicidal composition has excellent fungicidal effect, and shows excellent prevention and control effect on watermelon fusarium wilt, wheat foot rot, tobacco bacterial wilt, cotton damping-off, cotton sudden collapse, peanut root rot, peanut stem base rot, and damping-off, fusarium wilt, sudden collapse, root rot and the like of fruits, vegetables and legumes, and is environment-friendly, safe to crops, and has good application prospect while enhancing the broad spectrum and efficiency of fungicides.

Description

Technical Field

[0001] This application relates to the field of agricultural technology, specifically to a bactericidal composition of nano zinc oxide and Brucea javanica extract and its application. Background Technology

[0002] Nano zinc oxide (ZnO) is a novel, multifunctional, fine inorganic material that has attracted significant attention in agricultural applications in recent years. Its particle size is extremely small, typically between 1 and 100 nanometers. It possesses extremely high chemical activity, excellent catalytic and photocatalytic activity, enabling it to kill bacteria and resist infrared and ultraviolet radiation. In agriculture, nano zinc oxide kills pathogens through photocatalysis and direct contact, exhibiting advantages such as broad-spectrum bactericidal activity, rapid action, and long-lasting effect. It is suitable for the prevention and control of various crop diseases, such as tomato yellow leaf curl, tobacco black rot, and watermelon diseases. Furthermore, nano zinc oxide is non-toxic, odorless, and environmentally friendly, possessing good biocompatibility and causing no pollution or harm to the surrounding ecological environment.

[0003] *Brucea javanica*, widely distributed in southern China, belongs to the Caryophyllaceae family. Its seeds contain various bioactive components, and its extracts possess multiple effects, including anti-tumor, antibacterial, and antiviral activity. The alkaloids in *Brucea javanica* can inhibit the growth of various Gram-positive and Gram-negative bacteria, exerting their bactericidal effect by interfering with bacterial cell wall synthesis or protein synthesis. This broad-spectrum antibacterial activity makes *Brucea javanica* extract a promising candidate for agricultural fungicide applications. Currently, it is mainly used for plant disease control, soil disinfection, and seed treatment. Compared with chemical pesticides, *Brucea javanica* extract has many advantages as an agricultural fungicide. First, it is derived from a natural plant, making it environmentally friendly and less likely to cause phytotoxicity or residue problems. Second, *Brucea javanica* extract has broad-spectrum antibacterial activity, capable of controlling various crop diseases. Furthermore, *Brucea javanica* extract can also promote crop growth and development, improving crop yield and quality.

[0004] No reports have been found in the existing technology regarding the combination of nano zinc oxide and Brucea javanica extract. Summary of the Invention

[0005] This invention relates to a bactericidal composition containing nano zinc oxide and Brucea javanica extract, which has a synergistic effect in the prevention and control of agricultural diseases.

[0006] This invention uses nano zinc oxide and Brucea javanica extract as active ingredients to obtain a fungicide composition for preventing and controlling diseases and pests, which can reduce the use of chemical pesticides and fungicides, while effectively preventing and controlling a variety of plant diseases and pests.

[0007] The bactericidal composition of the present invention comprises nano zinc oxide and Brucea javanica extract as active ingredients, wherein the mass ratio of nano zinc oxide to Brucea javanica extract is 40:1-1:40, preferably 7:1-1:2.

[0008] Preferably, the bactericidal composition is mixed with pesticide excipients to prepare a formulation suitable for agricultural use, including wettable powder (WP), aqueous solution (AS), water-dispersible granules (WG), suspension concentrate (SC), and microcapsule (CS).

[0009] Preferably, the bactericidal composition is formulated as a suspension seed coating agent, and the pesticide excipients are wetting agents, dispersants, thickeners, film-forming agents, warning colors, defoamers, antifreeze agents, pH adjusters, and water.

[0010] Preferably, the composition of the present invention comprises, by weight percentage, the following components: 10-40% nano zinc oxide, 4-30% Brucea javanica extract, 10-20% wetting agent, 2-5% dispersant, 0.5-4.5% thickener, 0.5-1% film-forming agent, 2-5% warning color, 0.1-2% defoamer, 3-10% antifreeze agent, 0.5-2% pH adjuster, and water to 100.0%.

[0011] Preferably, the composition comprises the following components in the indicated mass fractions: 35% nano zinc oxide, 5% Brucea javanica extract, 13% wetting agent, 3% dispersant, 2% thickener, 0.8% film-forming agent, 4% warning color, 3% antifreeze agent, 0.5% defoamer, 0.5% pH adjuster, and 33.2% water.

[0012] Preferably, the wetting agent is selected from one or more combinations of alkyl naphthalene sulfonate formaldehyde condensate, a mixture of alkyl naphthalene sulfonate and anionic wetting agent, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, polyoxyethylene fatty acid, alkyl aryl polyethylene glycol ether, alkyl sulfonate, aryl sulfonate, fatty acid polyethylene glycol, polyoxyethylene phenol formaldehyde condensate, polyoxyethylene polyoxypropylene ether block copolymer, fatty alcohol polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene ether sulfonate, lignin and its derivative sulfonates, fatty acid ethane adduct phosphate, and alkylphenol polyoxyethylene ether phosphate; the dispersant is selected from one or more combinations of polycarboxylate and sodium 2-naphthalenesulfonic acid formaldehyde polymer (NNO). The composition includes: a thickener selected from one or more of silica, bentonite, and xanthan gum; a film-forming agent selected from one or more of modified carboxypropyl cellulose, polyvinyl alcohol, gum arabic, animal glue, pectin, xanthan gum, methylcellulose, ethylcellulose, sodium carboxymethyl cellulose, sodium alginate, polyethylene glycol, polyvinylpyrrolidone, polyacrylamide, and sodium polyacrylate; a warning color selected from acid red and rose essence; a defoamer selected from one or more of polyether defoamers, higher alcohols, tributyl phosphate, and polysiloxane defoamers; an antifreeze agent selected from one or more of ethylene glycol, propylene glycol, glycerol, and inorganic salts; and a pH adjuster selected from one or more of glacial acetic acid, citric acid, and phosphoric acid.

[0013] The method for preparing the bactericidal composition of the present invention into a suspension seed coating agent is as follows:

[0014] S1. Weigh out nano zinc oxide, Brucea javanica extract, dispersant, defoamer, wetting agent, and water.

[0015] S2. Stir the above materials for 40 minutes until they are evenly mixed. Then, pulverize them using an ultra-fine pulverizer and stir for another 40 minutes until the particle size reaches D50 of 2-3 μm and D90 < 4 μm.

[0016] S3. Add thickener, film-forming agent, warning color, antifreeze, and pH adjuster. After all indicators are tested and found to be qualified, the finished product is obtained.

[0017] The bactericidal composition of the present invention can be used to prevent and control a variety of crop diseases, including watermelon wilt, wheat stem base rot, tobacco bacterial wilt, cotton damping-off, cotton seedling blight, peanut root rot, peanut stem base rot, as well as damping-off, wilt, seedling blight, and root rot of fruits, vegetables, and beans.

[0018] The beneficial effects of this invention are:

[0019] This invention uses inorganic materials and plant extracts as main raw materials to prepare a plant disease control agent. This fungicide composition, when used to coat plant seeds, significantly reduces the occurrence of diseases. Furthermore, the fungicidal effect of nano-inorganic materials further enhances the efficacy and prolongs the effect of the control agent, thereby reducing the number of applications, alleviating planting labor, and lowering costs. This plant fungicide composition exhibits excellent control effects against a variety of plant diseases, with no observed phytotoxicity. Detailed Implementation

[0020] The present invention will be further described below with reference to embodiments, but the present invention is not limited thereto.

[0021] All reagents used in the following embodiments of the present invention can be obtained commercially or in-house. The plant pathogenic fungi used were cultured in the laboratory. Specifically, the Brucea javanica extract used in the following embodiments was Brucea javanica powder, purchased from Baoji Kaiweikang Biotechnology Co., Ltd.; the nano zinc oxide used was nano zinc oxide powder, purchased from Beijing Jiaanheng Technology Co., Ltd. Furthermore, unless otherwise specified, all percentages mentioned in the following embodiments are mass percentages.

[0022] The present invention will be further illustrated below with reference to the embodiments:

[0023] Example 1: Seed coating agent of nano zinc oxide and Brucea javanica extract (7:1)

[0024] S1. Weigh out the following mass percentages: 35% nano zinc oxide, 5% Brucea javanica extract, 3% polycarboxylate, 0.5% tributyl phosphate, 5% alkyl naphthalene sulfonate and anionic wetting agent, and 41.2% water.

[0025] S2. Stir the above materials for 40 minutes to mix them evenly, and then grind them in a sand mill for 40 minutes until the particle fineness reaches D50 of 2-3μm and D90 < 4μm.

[0026] S3. Add 2% silica, 0.8% modified carboxypropyl cellulose, 4% acid red, 3% ethylene glycol, and 0.5% glacial acetic acid. Stir well and test each indicator. If it passes the test, the suspension seed coating agent is obtained.

[0027] Example 2: Seed coating agent of nano zinc oxide and Brucea javanica extract (3:1)

[0028] S1. Weigh out the following mass percentages: 30% nano zinc oxide, 10% Brucea javanica extract, 3% polycarboxylate, 0.5% higher alcohol, 5% alkyl naphthalene sulfonate and anionic wetting agent, and 41.2% water.

[0029] S2. Stir the above materials for 40 minutes to mix them evenly, and then grind them in a sand mill for 40 minutes until the particle fineness reaches D50 of 2-3μm and D90 < 4μm.

[0030] S3. Add 2% silica, 0.8% modified carboxypropyl cellulose, 4% rose extract, 3% ethylene glycol, and 0.5% citric acid. Stir well and test each indicator. If it passes the test, the suspension seed coating agent is obtained.

[0031] Example 3: Seed coating agent of nano zinc oxide and Brucea javanica extract (6:1)

[0032] S1. Weigh out the following mass percentages: 30% nano zinc oxide, 5% Brucea javanica extract, 3% polycarboxylate, 0.5% higher alcohol, 5% alkyl naphthalene sulfonate and anionic wetting agent, and 47.2% water.

[0033] S2. Stir the above materials for 40 minutes to mix them evenly, and then grind them in a sand mill for 40 minutes until the particle fineness reaches D50 of 2-3μm and D90 < 4μm.

[0034] S3. Add 1% xanthan gum, 0.8% modified carboxypropyl cellulose, 4% Acid Red, 3% ethylene glycol, and 0.5% citric acid. Stir well and test each indicator. If it passes the test, the suspension seed coating agent is obtained.

[0035] Experimental Example 1

[0036] In vitro synergistic toxicity of nano-zinc oxide and Brucea javanica extract combined on wheat stem base rot:

[0037] Test material: The tested pathogen was *Fusarium graminearum* (Pseudomonas graminearum). Fusarium pseudogramineum Fusarium pseudograss was isolated and purified from wheat with naturally occurring stem base rot in the field. After morphological and pathogenic identification, the strain was frozen in an ultra-low temperature freezer for later use.

[0038] Test reagents: nano zinc oxide, extract of Brucea javanica.

[0039] 1. Indoor synergistic virulence effect of nano-zinc oxide and Brucea javanica extract combined with Fusarium graminearum.

[0040] Experimental Method: Referring to the mycelial growth rate method in "People's Republic of China Agricultural Industry Standard NY / T1156.6-2006 Pesticide Indoor Bioassay Test - Part 6: Determination of Combined Effects of Mixtures", a stock solution of 10000 mg / L of pesticide was prepared. Then, appropriate amounts were mixed according to the predetermined ratio in Table 1 and five concentration gradients were prepared using an aqueous solution containing 1% Tween 80. These were then added to PDA medium at 45-50℃, with a pesticide-to-medium volume ratio of 1:9. The mixture was thoroughly mixed and poured into sterilized Petri dishes. After cooling, a virus-containing medium was formed. Each concentration was repeated five times. An aqueous solution containing 1% Tween 80 was used as a control. Subsequently, under aseptic conditions, pathogenic fungal discs were inoculated into the center of the virus-containing medium. The Petri dishes were then incubated in an incubator at 25℃ and 90% humidity. When the colony radius on the control plate reached approximately 2 / 3 of the plate radius, the colony diameter for each treatment was measured using the cross-multiplication method. The percentage of mycelial growth inhibition for each treatment was calculated. EC was calculated using linear regression analysis between the probability value of the inhibition rate and the logarithm of the series concentrations. 50 .

[0041] The interaction of the mixtures was evaluated using the Wadley method, and the calculation formula is as follows:

[0042] Mycelial growth inhibition rate (%) = (Control colony diameter - Treated colony diameter) / (Control colony diameter - Mycelial cake diameter) × 100%

[0043] EC 50 (Theoretical value) = (P) A +P B ) / (P A / EC 50 A+P B / EC 50 B)

[0044] SR=EC 50 (Theoretical value) / EC 50 (Measured value)

[0045] Among them, P A P represents the percentage content of drug A in the mixture. B This represents the percentage content of drug B in the mixture.

[0046] SR≤0.5 indicates an antagonistic effect, 0.5<SR<1.5 indicates an additive effect, and SR≥1.5 indicates a synergistic effect.

[0047] Table 1 shows that the combination of nano-zinc oxide and Brucea javanica extract has a good bactericidal effect against Fusarium oxysporum. When the mixture is combined at a mass ratio of 10:1 or 1:2-3, the synergistic coefficient (SR) is between 0.5 and 1.5, exhibiting an additive effect. For all other mass ratios, the synergistic coefficient (SR) is greater than 1.5, showing a synergistic effect, especially at a mass ratio of 7:1, where the synergistic coefficient (SR) is the highest. This indicates that combining nano-zinc oxide with Brucea javanica extract can improve the control effect against Fusarium oxysporum.

[0048] Table 1. In vitro synergistic virulence of nano-zinc oxide and Brucea javanica extract combined with Fusarium oxysporum pseudobulb.

[0049]

[0050] Note: The X value is converted by taking the logarithm with base 10, and the y value is the probability value.

[0051] 2. Effects of a mixture of nano-zinc oxide and Brucea javanica extract on wheat germination and seedling growth

[0052] Zaojiao Village, Dongshangguan Township, Fuping County, Shaanxi Province, is located at an altitude of 380 meters in the transitional zone between the Guanzhong Plain and the Shaanbei Plateau. It has a warm temperate semi-humid climate, with loess soil. The land is flat and equipped with a relatively complete irrigation and drainage system. The cultivation conditions in the designated plots are consistent and conform to the agricultural practices of the region.

[0053] 2.1 Experimental crop: Wheat, variety Yannong 5286 (a susceptible variety).

[0054] 2.2 The dosage and numbering of the medicines are as follows:

[0055] Table 2 Chemical Treatment

[0056]

[0057] 2.3 Application Method

[0058] 2.3.1 Application method: Use seed coating treatment.

[0059] 2.3.2 Application time and frequency: Coating should be carried out on October 15th. After coating, the seeds should be air-dried in a cool place for 2-3 days before proceeding with germination, sowing, etc. as usual.

[0060] 2.4 Survey, Recording and Measurement Methods

[0061] 2.4.1 Meteorological and Soil Data

[0062] 2.4.1.1 Meteorological Data

[0063] On the day of sowing, October 18, the temperature was 13-17℃, with light rain turning to moderate rain, southeast wind at level 3-4, and RH at 71%-84%; on the day of the survey, November 5, the weather was sunny, with the temperature at 6-12℃ and RH at 28%-53%; on April 28 of the following year, the temperature was 16-25℃, with the weather turning to cloudy, and RH at 29%-48%.

[0064] 2.4.1.2 Soil Data

[0065] The soil type of the experimental plot is loess soil, which is loose.

[0066] 2.4.2 Survey methods, timing, and frequency

[0067] 2.4.2.1 Survey time and number of times

[0068] Disease incidence was investigated at the 3-leaf stage (November 5th) and before heading (April 28th of the following year). The experiment proceeded smoothly under normal climatic conditions with no particularly severe weather.

[0069] 2.4.2.2 Survey Methods

[0070] Based on Section 104 of the "Field Efficacy Trial Guidelines (II)" and the SOP of the Institute of Plant Protection, Henan Academy of Agricultural Sciences G03 004: Investigate the emergence period of different treatments. When the wheat seedlings have fully emerged, investigate the emergence rate of each treatment plot. Each treatment is replicated 6 times, with each plot being 30m². 2 (3m×10m); During the 3-leaf stage, five points were sampled along the diagonal, and 100 plants were investigated at each point to determine the disease incidence rate and seedling quality (including plant height, number of roots, root length, and fresh weight of 100 plants). Before heading in the field, five points were randomly sampled in each plot, and 50 clumps (holes) were investigated at each point to record the disease incidence rate.

[0071] 2.4.2.3 Method for calculating drug efficacy

[0072] The calculation formula is as follows:

[0073] Disease incidence rate (%) = Number of diseased seedlings / Total number of seedlings surveyed 100%

[0074] Control efficacy (%) = (Disease incidence in blank control area - Disease incidence in treatment area) / Disease incidence in blank control area 100%

[0075] 2.4.3 Direct impact on crops: No pesticide damage was found.

[0076] 2.5 Results and Analysis

[0077] 2.5.1 Effects of experimental agent treatments on emergence rate and seedling quality

[0078] The results of the survey on emergence rate and seedling quality shown in Table 3 indicate that seed coating treatments at various concentrations of the tested agents had no effect on wheat emergence rate and seedling quality.

[0079] Table 3. Effects of experimental agent treatments on emergence rate and seedling quality.

[0080]

[0081] 2.5.2 Effect of pesticide treatment on the control of wheat stem rot

[0082] The efficacy test results show that the control effect of the test agent 40% nano zinc oxide·Brucea javanica extract seed dressing agent on wheat stem base rot increases with the increase of the application dosage.

[0083] A survey conducted on wheat at the 3-leaf stage (November 5th) showed that the control efficacy of the tested pesticide, 40% nano zinc oxide·Brucea javanica extract seed dressing agent at 20.0 g / 100 kg, 13.3 g / 100 kg, and 10 g / 100 kg, was 76.92%, 72.65%, and 63.25%, respectively. The control efficacy of the control pesticide, 99% nano zinc oxide, was 68.38%, and the control efficacy of the control pesticide, 90%Brucea javanica extract, was 64.96%. A survey conducted at the heading stage (April 28th of the following year) showed that the control efficacy of the tested pesticide 40% nano zinc oxide·Brucea javanica extract seed dressing agent at 20.0 g / 100 kg, 13.3 g / 100 kg, and 10 g / 100 kg was 81.15%, 76.68%, and 69.32%, respectively. The control efficacy of the control pesticide 99% nano zinc oxide was 72.52%, and the control efficacy of the control pesticide 90%Brucea javanica extract was 69.65%.

[0084] During the experiment, at the three-leaf stage of wheat (November 5th), each treatment corresponded to 6 sampling points, and each sampling point corresponded to 100 plants. The results of variance analysis showed that there were significant differences in the control efficacy between the high concentration (20.0 g / 100 kg) and medium concentration (13.3 g / 100 kg) and low concentration (10 g / 100 kg) treatments of the tested agent 40% nano zinc oxide·Brucea javanica extract seed coating agent. There were also significant differences in the control efficacy between the low concentration and the control agent 99% nano zinc oxide treatment. There were also significant differences in the control efficacy between the high concentration (20.0 g / 100 kg) and medium concentration (13.3 g / 100 kg) treatments and the control agents 99% nano zinc oxide and 90% Brucea javanica extract treatments. There were no significant differences among other treatments.

[0085] During the heading stage, significant differences in control efficacy were observed among high-concentration (20.0 g / 100 kg), medium-concentration (13.3 g / 100 kg), and low-concentration (10 g / 100 kg) treatments of the tested 40% nano zinc oxide·Brucea javanica extract seed dressing agent. The low-concentration (10 g / 100 kg) treatment showed a significant difference in control efficacy compared to the control agent 99% nano zinc oxide, but no significant difference compared to the 90% Brucea javanica extract treatment. Significant differences in control efficacy were also observed between high-concentration (20 g / 100 kg), medium-concentration (13.3 g / 100 kg), and the control agents 99% nano zinc oxide and 90% Brucea javanica extract alone.

[0086] Field trials have shown that 40% nano zinc oxide·Brucea javanica extract seed dressing agent has a good control effect on wheat stem base rot, has no significant impact on wheat emergence and non-target organisms, and is safe for wheat growth.

[0087] Table 3. Effects of pesticide treatments on wheat stem rot control.

[0088]

[0089] Note: Data in the table are mean ± standard deviation. LSD method was used for significance analysis; different lowercase letters indicate that data in the same column are significant at the 5% level.

Claims

1. A fungicidal composition, characterized by, The active ingredients include nano-zinc oxide and brucea javanica extract, and the mass ratio of the nano-zinc oxide and the brucea javanica extract is 9:1-1:

1. The brucea javanica extract is specifically brucea javanica powder, which is specifically purchased from Baoji Kaivikang Biotechnology Co., Ltd.

2. The bactericidal composition according to claim 1, characterized by, The fungicidal composition is mixed with a pesticide adjuvant to prepare a suitable agricultural dosage form, including wettable powder (WP), aqueous solution (AS), water dispersible granules (WG), suspension concentrate (SC) and microcapsule (CS).

3. The germicidal composition of claim 2, wherein: The fungicidal composition is prepared into a suspension seed coating agent, and the pesticide adjuvant is wetting agent, dispersant, thickening agent, film-forming agent, warning color, defoaming agent, antifreeze agent, pH regulator and water.

4. The germicidal composition according to claim 3, characterized in that, The suspension seed coating agent contains, in terms of mass percentage, 10-40% nano-zinc oxide, 4-30% brucea javanica extract, 10-20% wetting agent, 2-5% dispersant, 0.5-4.5% thickening agent, 0.5-1% film-forming agent, 2-5% warning color, 0.1-2% defoaming agent, 3-10% antifreeze agent, 0.5-2% pH regulator and water, with the total being 100.0%.

5. Use of the fungicidal composition according to any one of claims 1-4 for controlling crop diseases; the disease is wheat foot rot, and the pathogenic bacterium of the wheat foot rot is Fusarium pseudograminearum.

Images