Microbial fertilizer for preventing and treating okra root rot

Abstract

The invention relates to a microbial fertilizer for preventing and treating okra root rot, and belongs to the technical field of microbial fertilizers. The microbial fertilizer comprises the following three components: a) bacillus amyloliquefaciens, b) okra straw ferment, konjac glucomannan, shell powder, mineral source potassium fulvic acid and polyglutamic acid, and c) a compound of biomass power plant ash and diatomite, wherein the formula is as follows: a) bacillus amyloliquefaciens; b) okra straw ferment, konjac glucomannan, shell powder, mineral source potassium fulvic acid and polyglutamic acid; wherein the preservation number of the bacillus amyloliquefaciens is CCTCC (China Center For Type Culture Collection) NO: M20221206; when the microbial fertilizer is prepared, 1 * 10 CFU / g of the microbial agent of the component 1 and the dried component 2 are mixed to enable viable bacteria to reach 3 * 10-6 * 10 CFU / g, and then the component 3 is added and uniformly stirred at normal temperature and low humidity; when the microbial fertilizer is applied in the okra planting process, mycotoxin in rhizosphere soil of the okra can be reduced, the content of resistant substances in root systems can be increased, and root rot caused by fusarium oxysporum and the like can be prevented and treated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microbial fertilizers, and particularly relates to a microbial fertilizer for preventing and treating okra root rot. BACKGROUND

[0002] Okra is a kind of characteristic vegetable with rich nutritional value, and its large-scale planting area has been expanding in China in recent years. However, the production process is increasingly harmed by root rot, which has become a key bottleneck restricting the yield and quality improvement of okra. Okra root rot is mainly caused by pathogenic fungi such as Fusarium oxysporum f. sp. vasinfectum (FOV), F. solani f. sp. glycines (FSG), and Pythium ultimum (PU). Fusarium oxysporum Fusarium solani f. sp. melongenae Pythium ultimum The pathogenic fungi can be transmitted through soil, seeds, and agricultural operations, and easily break out on a large scale under environmental conditions such as continuous cropping, high humidity, and soil compaction.

[0003] At the early stage of the disease, brown spots appear on the root system of okra, and gradually rot with the development of the disease, resulting in the loss of the function of the root system in absorbing water and nutrients, and the yellowing and wilting of the leaves, and even the death of the whole plant. Under conventional planting conditions, the incidence of okra root rot can reach 30% to 50%, and the yield reduction rate of severely diseased plots is more than 60%, even leading to absolute yield loss, which causes great economic losses to the growers. At the same time, the pathogenic fungi can survive in the soil for a long time (the survival period can reach 5 to 8 years), and the pathogenic fungi accumulate continuously in the continuous cropping plots, and the risk of disease occurrence increases year by year, further increasing the difficulty of okra planting. At present, the prevention and control measures for okra root rot in agricultural production mainly include chemical control, agricultural control, and biological control, but all have obvious defects and cannot meet the needs of large-scale and green planting. Chemical control can inhibit the spread of the disease in the short term, but long-term use can lead to drug resistance of the pathogenic fungi, and cause soil pollution, pesticide residues in agricultural products, and other problems, which do not meet the requirements of green agriculture and food safety; in terms of agricultural control, the rotation mode is difficult to be popularized on a large scale due to the limitation of arable land resources, the breeding process of disease-resistant varieties is slow, and the prevention and control effect of deep ploughing is also lagging; the existing biological control products mostly use broad-spectrum strains, and the targeted inhibition effect on okra root rot is insufficient, the average control rate is less than 60%, and the product formula is seriously homogenized, the stability is poor, and it is difficult to achieve synergistic effect in soil remediation and plant nutrition supply.

[0004] Therefore, it is of great significance for the green production of okra to develop a complex microbial fertilizer which is compounded by functional microorganisms, organic carriers, and soil conditioners, can effectively improve the rhizosphere microecology, persistently inhibit the pathogenic fungi, and improve the plant resistance. SUMMARY

[0005] ​​In order to overcome the problems in the background art, the present application provides a microbial fertilizer for preventing and treating gossyprius root rot, which can not only effectively inhibit the growth and reproduction of the pathogen of gossyprius root rot and reduce the incidence of diseases, but also provide sufficient nutrients for the growth of gossyprius, promote the growth of plants, and improve the yield and quality of gossyprius.

[0006] To achieve the above-mentioned object, the present application is realized by the following technical scheme: a microbial fertilizer for preventing and treating gossyprius root rot mainly comprises: Component 1: Bacillus amyloliquefaciens (Bacillus amyloliquefaciens) Bacillus amyloliquefaciens ); Component 2: gossyprius straw fermented product, konjac glucomannan, shell powder, potassium fulvic acid from mineral sources, and polyglutamic acid Component 3: composed of a compound of biomass power plant ash and diatomite.

[0007] Further, the weight percentage content of each component in the microbial fertilizer is: component 1 accounts for 1% to 5%, component 3 accounts for 10% to 25%, and the balance is component 2.

[0008] Further, the preparation method of the microbial fertilizer comprises: drying component 2 at 50 to 60°C for 2 to 3 hours, then mixing it with Bacillus amyloliquefaciens bacterial agent of component 1 with a viable bacterial content of 1×10¹¹ CFU / g, stirring uniformly by gradient dilution method, so that the viable bacterial content of Bacillus amyloliquefaciens in the mixed material reaches 3×10 9 ~ 6×10 9 CFU / g; and then adding component 3 to it, stirring for 30 to 40 minutes at room temperature and in an environment with a relative humidity of ≤40%, and mixing uniformly.

[0009] Further, the viable bacterial content of Bacillus amyloliquefaciens in component 1 is 3×10 9 ~ 6×10 9 CFU / g; and in component 2, the weight ratio of gossyprius straw fermented product, konjac glucomannan, shell powder, potassium fulvic acid from mineral sources, and polyglutamic acid is 58 to 68: 14 to 18: 10 to 14: 4 to 6: 2 to 4.

[0010] Further, the preparation method of the gossyprius straw fermented product is: crushing gossyprius straw to a particle size of 1 to 3 mm, adding a humification agent and brown sugar at a mass ratio of 100:5:3, the humification agent is compounded by Aspergillus oryzae, yeast, and actinomycetes at a ratio of 2:1:1; adjusting the moisture content of the mixture to 60% to 65%, aerobic fermentation at 30 to 35°C for 15 to 20 days, turning the heap 3 to 4 times during the period; after the fermentation is completed, drying the material to a moisture content of ≤12%, crushing to pass through an 80-mesh sieve; the obtained gossyprius straw fermented product has an organic matter content of ≥50% and a humic acid content of ≥15% in terms of dry matter.

[0011] Further, the purity of the konjac glucomannan is ≥85%; the shell powder is calcined at 800-900 DEG C for 2-3h, and is crushed to pass through a 100 mesh sieve, wherein the CaCO3 content is ≥90%; in the potassium abietinate, the abietic acid content is ≥55%, and the potassium oxide content is ≥35%; the purity of the polyglutamic acid is ≥90%.

[0012] Further, in the component 3, the weight ratio of the biomass power plant ash to the diatomite is 3:1; in the biomass power plant ash, the silicate content is 18-22% and the potassium salt content is 4-5% based on the dry matter; the specific surface area of the diatomite is ≥200m2 / g, and the pore size distribution is 20-50nm.

[0013] The second aspect of the present application provides the use of the microbial fertilizer in reducing the content of the fungal toxin in the okra rhizosphere soil, and / or, increasing the content of the resistance substance in the okra root system, and / or, preventing and treating the okra root rot.

[0014] Further, the pathogenic bacteria of the okra root rot is one or more of Fusarium oxysporum ( Fusarium oxysporum ), Fusarium solani f. sp. glycines ( Fusarium solani ), f. sp. melongenae ), and Pythium ultimum ( Pythium ultimum ).

[0015] The third aspect of the present application also provides a method for preventing and treating the okra root rot, characterized in that the above microbial fertilizer is applied to the okra rhizosphere soil, is ploughed into the soil, and the application amount is 50-60kg / 667m2; then the rhizosphere hole application is carried out at the initial flowering stage and the fruiting stage of the okra respectively, and the application amount of each time is 40-45kg / 667m2, and water is poured after the application, and the whole growth period is applied for 3 times.

[0016] The beneficial effects of the present application are as follows: 1. The biological fertilizer can precisely prevent and control the okra root rot and solve the problem of continuous cropping of soil. First, Bacillus amyloliquefaciens is used as the core, which can target inhibit the main pathogenic bacteria such as Fusarium oxysporum and Pythium ultimum, and the disease control rate is greatly improved, which can avoid the yield loss of heavy disease plots; at the same time, the accumulation of soil fungal toxins is reduced, the safety risk of fruits is reduced, and the problems of strong drug resistance and pesticide residues in the existing chemical control, and poor targeting in the conventional biological control are solved; secondly, the soil permeability and humidity are optimized by the component 3, and harmful ions are adsorbed, and the soil pH value is adjusted by the shell powder in the component 2, which can inhibit the long-term survival of pathogenic bacteria in the soil, and effectively alleviate the problem of disease aggravation in the continuous cropping plot; and the okra straw fermented material in the component 2 can supplement soil organic matter and nutrients, and improve the soil fertility degradation, and build a solid soil foundation for the growth of okra.

[0017] 2. This microbial fertilizer can also take into account both nutrient supply and green production, and is suitable for the needs of large-scale planting. The okra straw fermentation product, konjac glucomannan, and mineral potassium humate in component 2 can form a compound nutrient system of "organic + inorganic + functional substances". Combined with the fertilization methods of broadcasting before transplanting and root hole application during the initial flowering / full fruiting period, it can meet the nutrient needs of okra throughout its entire growth period. At the same time, it can induce the roots to synthesize resistance substances, and control diseases from two dimensions: external inhibition of pathogens and internal enhancement of plant resistance, thus ensuring fruit quality and yield.

[0018] Biological Preservation The Bacillus amyloliquefaciens used in this invention ( Bacillus amyloliquefaciens The strain was deposited on August 8, 2022, at the China Center for Type Culture Collection (CCTCC), located at No. 299 Bayi Road, Wuchang District, Wuhan, Hubei Province, China (Wuhan University), with accession number CCTCC NO: M20221206. The preservation information of the strain has been published in the invention patent application number CN202211478828.9. Detailed Implementation

[0019] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0020] Based on the above findings, the present invention provides a microbial fertilizer for preventing and controlling okra root rot, the bio-fertilizer mainly comprising: Component 1: Bacillus amyloliquefaciens ( Bacillus amyloliquefaciens ); Component 2: Okra straw fermentation product, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid; Component 3: Composed of a mixture of biomass power plant ash and diatomaceous earth.

[0021] That is, the microbial fertilizer provided by this invention is as follows: (1) Bacillus amyloliquefaciens; (2) Bacillus amyloliquefaciens, okra straw ferment, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid; (3) Bacillus amyloliquefaciens, biomass power plant ash and diatomaceous earth compound; (4) Okra straw ferment, konjac glucomannan, shell powder, mineral-derived potassium humate, polyglutamic acid and biomass power plant ash and diatomaceous earth compound; (5) Okra straw ferment, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid; (6) Biomass power plant ash and diatomaceous earth compound; (7) Bacillus amyloliquefaciens, okra straw ferment, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid, biomass power plant ash and diatomaceous earth compound.

[0022] The inventors discovered in their research that the microbial composition exhibits better control effects against okra root rot when the components are used in a specific weight ratio. Therefore, according to a preferred embodiment of the present invention, the total amount of Bacillus amyloliquefaciens used, based on the total weight of the microbial agent, is 1-5% by weight, preferably 3-5% by weight, and more preferably 4-5% by weight.

[0023] The viable bacterial content of Bacillus amyloliquefaciens in component 1 is 3 × 10⁻⁶. 9 ~6×10 9 CFU / g, preferably 4×10 9 ~6×10 9 CFU / g, more preferably 5×10 9 ~6×10 9 CFU / g.

[0024] According to a preferred embodiment of the present invention, the weight ratio of okra straw fermentation product, konjac glucomannan, shell powder, mineral-derived potassium humate, and polyglutamic acid is 58-68:14-18:10-14:4-6:2-4, preferably 63-68:15-18:12-14:5-6:3-4, and more preferably 64-68:16-18:13-14:5.5-6:3.5-4.

[0025] According to a preferred embodiment of the present invention, the total amount of biomass power plant ash is 10% to 25% by weight, preferably 20% to 25% by weight.

[0026] In this invention, there are no particular restrictions on the raw materials used in the above composition (such as okra straw fermentation, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid, biomass power plant ash). They can be any relevant products in the art that can be used to prepare the composition, either commercially available products or products prepared by the author according to the prior art.

[0027] The present invention further provides a method for preparing the above composition. According to a preferred embodiment of the present invention, the okra straw fermentation product, konjac glucomannan, shell powder, mineral-derived potassium humate, and polyglutamic acid in component 2 are mixed in the stated proportions, dried at 50-60°C for 2-3 hours, and cooled to room temperature for later use; the Bacillus amyloliquefaciens agent of component 1 with a viable bacterial content of 1×10¹¹ CFU / g is mixed with the pretreated component 2, and stirred evenly using a gradient dilution method to control the viable bacterial content of Bacillus amyloliquefaciens in the mixed material to reach 3×10¹¹ CFU / g. 9 ~6×10 9 CFU / g; Mix the biomass power plant ash and diatomaceous earth in component 3 in a certain proportion, and then add them to the mixture obtained above. Stir for 30 to 40 minutes at room temperature and relative humidity ≤40% to ensure uniform mixing; Package the compounded material and store it in a cool and dry place.

[0028] In this invention, there are no particular restrictions on the specific storage and use forms of the microbial composition. Since the raw materials used in this microbial composition are primarily solid, and the preparation method involves simply mixing the components in proportion, the microbial composition can be stored or used directly as a solid formulation. Considering the differences in crops, planting methods, and planting conditions, the composition can also be mixed with a certain amount of water to prepare a liquid or slurry (suspension) formulation for storage or use.

[0029] The application of Bacillus amyloliquefaciens provided in the second aspect of the present invention, or the microbial fertilizer described in the first aspect, in reducing the content of fungal toxins in the rhizosphere soil of okra, and / or increasing the content of resistance substances in okra roots, and / or preventing okra root rot.

[0030] According to a preferred embodiment of the present invention, the crop is okra.

[0031] In this invention, the rhizosphere soil fungal toxins of okra refer to Fusarium toxin, Phytophthora toxin, and Rhizoctonia solani toxin; the root resistance substances refer to salicylic acid, jasmonic acid, and phenolic substances in okra roots.

[0032] In this invention, the prevention and control of crop root diseases refers to preventing or reducing the occurrence of crop diseases, or reducing the losses caused by diseases after they occur.

[0033] Preferably, the crop disease is selected from okra root rot.

[0034] According to some preferred embodiments of the present invention, the pathogen causing the okra root rot is Fusarium oxysporum (Fusarium oxysporum). Fusarium oxysporum ), and / or, Fusarium solani ( Fusarium solani f. sp. f. sp. melongenae), and / or, ultimate Pythium ( Pythium ultimum ).

[0035] The third aspect of the present invention provides a method for controlling root and stem diseases by using microbial fertilizer to prevent okra root rot, the method comprising applying the composition described in the first aspect to the rhizosphere soil of okra.

[0036] In other words, the above methods can include the following approaches: 1) Apply Bacillus amyloliquefaciens directly to the rhizosphere soil of crops (usually by applying solid inoculants directly to the rhizosphere soil of crops, or by culturing Bacillus amyloliquefaciens and then applying the culture to the soil). 2) Apply microbial fertilizer that does not contain Bacillus amyloliquefaciens to the rhizosphere soil of crops; 3) Apply microbial fertilizer containing Bacillus amyloliquefaciens to the rhizosphere soil of crops.

[0037] In this invention, the crop is okra.

[0038] Preferably, the pathogen causing okra root rot is Fusarium oxysporum (Fusarium oxysporum). Fusarium oxysporum ), and / or, Fusarium solani ( Fusarium solani f. sp. f. sp. melongenae ), and / or, ultimate Pythium ( Pythium ultimum ).

[0039] The specific characteristics of the Bacillus amyloliquefaciens and the composition used in the method provided by this invention are as described above and will not be repeated here.

[0040] In this invention, there are no particular restrictions on the specific dosage of Bacillus amyloliquefaciens and the composition, as long as it can play a role in preventing and controlling root and stem diseases.

[0041] According to a preferred embodiment of the present invention, the amount of Bacillus amyloliquefaciens used in method 1) is such that the content of Bacillus amyloliquefaciens in the composition is 3 × 10⁻⁶. 9 ~6×10 9 CFU / g. The dosage of Bacillus amyloliquefaciens is calculated based on the amount of the composition applied and the number of Bacillus amyloliquefaciens contained therein, with liquid bacterial agents converted to 1g / mL.

[0042] The inventors of this invention also discovered in their research that adjusting the dosage of the aforementioned Bacillus amyloliquefaciens when planting different crops can further improve the crop's systemic resistance and disease prevention effects.

[0043] According to some preferred embodiments of the present invention, wherein, for the above-mentioned method 1): when applied to crop rhizosphere soil, the total dosage of the Bacillus amyloliquefaciens is not less than 50-60 kg / 667 m², preferably 55-60 kg / 667 m². 2 / Second-rate.

[0044] The composition provided by the present invention has a synergistic effect when used together with Bacillus amyloliquefaciens. Therefore, in order to obtain better results when using the above method 1), the amount of Bacillus amyloliquefaciens can be appropriately increased compared with the amount of Bacillus amyloliquefaciens applied with the bacterial agent in method 3).

[0045] Preferably, for method 3 above): when applied to crops, the total dosage of the composition is not less than 50-60 kg / 667 m³. 2 The preferred weight is 55-60 kg / 667 m³. 2 More preferably, it is 58-60 kg / 667 m 2 .

[0046] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are only used to further explain and illustrate the present invention, and are not intended to limit the present invention.

[0047] Example 1 In this embodiment, the okra straw fermentation product was prepared according to the method described in claim 3. Konjac glucomannan was purchased from Xi'an An'ao Biotechnology Co., Ltd., potassium humate (mineral source) was purchased from Jinan Yucai Chemical Co., Ltd., polyglutamic acid was purchased from Yunnan Provincial Microbial Fermentation Engineering Research Center Co., Ltd., potassium humate (mineral source) was purchased from Jinan Qinghai Chemical Co., Ltd., biomass power plant ash was purchased from Anhui Yingtianqing Biotechnology Co., Ltd., diatomaceous earth was purchased from Qingdao Haiyang Chemical Co., Ltd., and the inoculum was obtained by amplifying Bacillus amyloliquefaciens (see CN202211478828.9 for the method of obtaining the inoculum) into a liquid culture medium with a concentration of 1.0 × 10⁻⁶. 10 CFU / g.

[0048] I. Raw material ratio for microbial fertilizer (total weight 100kg) (1) Component 1 (Bacillus amyloliquefaciens inoculum): 1 kg The Bacillus amyloliquefaciens agent with preservation number CCTCC NO: M20221206 was selected, and its initial viable cell content was 1×10¹¹ CFU / g.

[0049] (2) Component 2: 89kg Okra straw fermentation product: 58.66 kg Konjac glucomannan: 14.16kg Shell powder: 10.11kg Potassium humate from mineral source: 4.05 kg Polyglutamic acid: 2.02kg (3) Component 3 (composite of biomass power plant ash and diatomaceous earth): 10kg II. Microbial Fertilizer Preparation Steps After mixing all the raw materials in component 2, dry them in an oven at 50-60℃ for 2 hours, controlling the moisture content to ≤12%, and then cool them to room temperature for later use. Then, add component 1 (Bacillus amyloliquefaciens inoculant) and the pretreated component 2 into a twin-helix mixer, and use a gradient dilution method to mix in three batches, stirring once every 5 minutes for 10 minutes each time, ensuring uniform dispersion of the inoculant. The final result showed that the viable Bacillus amyloliquefaciens content in the mixture was 3 × 10⁻⁶. 9 CFU / g; Finally, add component 3 to the above mixture, and continue stirring for 30 minutes at 25°C and 35% relative humidity. After mixing evenly, dispense and seal for storage.

[0050] III. Application Methods and Effect Verification 1. Application plan The soil type of the experimental plot was sandy loam, and the previous crop was okra with a root rot incidence rate of 35%. The experimental plot was 667 m².

[0051] 7 days before transplanting: Spread the microbial fertilizer evenly on the soil surface and plow it into the soil. The application rate is 50 kg / 667 m². Initial flowering stage: Apply fertilizer to the root zone at a rate of 40 kg / 667 m². Water promptly after application to promote fertilizer dissolution and root absorption. During the peak fruiting period: Apply fertilizer to the root zone at a rate of 40 kg / 667 m². Water promptly after application to promote fertilizer dissolution and root absorption.

[0052] 2. Effect detection Control group: No microbial fertilizer applied; Experimental group: Microbial fertilizer applied. Okra root rot incidence: 35% in the control group, 8% in the experimental group, with a control rate of 77.1%. Rhizosphere soil fungal toxin (fusarium acid) content: 850 ug / kg in the control group and 200 ug / kg in the experimental group, a decrease of 76.5%; Root resistance substance (flavonoid) content: 12ug / g in the control group and 28.5ug / g in the experimental group, an increase of 128%; Okra yield: 1800 kg / 667 m² in the control group and 2500 kg / 667 m² in the experimental group, representing an increase of 38.9%.

[0053] Example 2 I. Raw material ratio for microbial fertilizer (total weight 100kg) (1) Component 1 (Bacillus amyloliquefaciens inoculum): 3kg (2) Component 2: 79kg Okra straw fermentation product: 50.27 kg Konjac glucomannan: 12.77kg Shell powder: 9.58kg Potassium humate from mineral source: 3.99 kg Polyglutamic acid: 2.29kg (3) Component 3 (composite of biomass power plant ash and diatomaceous earth): 18kg II. Microbial Fertilizer Preparation Steps After mixing all raw materials in component 2, the mixture was dried in an oven at 50–60°C for 2.5 hours, controlling the moisture content to ≤10%, and then cooled to room temperature. Then, component 1 (Bacillus amyloliquefaciens inoculant) and the pretreated component 2 were added to a twin-helix mixer and stirred four times using a gradient dilution method, stirring once every 4 minutes for 12 minutes each time, to ensure uniform dispersion of the inoculant. The final result showed that the viable Bacillus amyloliquefaciens content in the mixture was 4.5 × 10⁻⁶. 9 CFU / g; Finally, add component 3 to the above mixture, and continue stirring for 35 minutes at 26°C and 38% relative humidity. After mixing evenly, dispense and seal for storage.

[0054] III. Application Methods and Effect Verification 1. Application plan The soil type of the experimental plot was clay loam. Okra had been continuously planted for 3 years, and the incidence of root rot was 42%. The experimental plot was 667 m².

[0055] Eight days before transplanting: Spread the microbial fertilizer evenly on the soil surface and plow it into the soil. The application rate is 60 kg / 667 m². Early flowering stage: Apply fertilizer to the root zone at a rate of 43 kg / 667 m², and water immediately after application; During the peak fruiting period: Apply fertilizer by root zone application at a rate of 43 kg / 667 m². Water promptly after application to promote fertilizer dissolution and root absorption.

[0056] 2. Effect detection Control group: No microbial fertilizer applied; Experimental group: Microbial fertilizer applied. Okra root rot incidence: 42% in the control group, 6% in the experimental group, with a control rate of 85.7%. Rhizosphere soil mycotoxin (Phytophthora) content: 1.05 mg / kg in the control group and 0.20 mg / kg in the experimental group, a decrease of 81.0%; Content of root resistance substances (polyphenols): 150 μg / g in the control group and 280 μg / g in the experimental group, an increase of 86.7%; Vitamin C content of okra fruit: 8 mg / 100g in the control group and 14 mg / 100g in the experimental group, an increase of 75%.

[0057] Example 3 I. Raw material ratio for microbial fertilizer (total weight 100kg) (1) Component 1 (Bacillus amyloliquefaciens inoculum): 5kg (2) Component 2: 70kg Okra straw fermentation product: 43.27 kg Konjac glucomannan: 11.46kg Shell powder: 8.91kg Potassium humate from mineral source: 3.82 kg Polyglutamic acid: 2.55kg (3) Component 3 (composite of biomass power plant ash and diatomaceous earth): 25kg II. Microbial Fertilizer Preparation Steps After mixing all raw materials in component 2, the mixture was dried in an oven at 50–60°C for 3 hours, controlling the moisture content to ≤8%, and then cooled to room temperature. Then, component 1 (Bacillus amyloliquefaciens inoculant) and the pretreated component 2 were added to a twin-screw mixer and stirred five times using a gradient dilution method, stirring once every 3 minutes for 15 minutes each time, ensuring uniform dispersion of the inoculant. The final result showed that the viable Bacillus amyloliquefaciens content in the mixture was 4.5 × 10⁻⁶. 9 CFU / g; Finally, add component 3 to the above mixture, and continue stirring for 40 minutes at 28°C and 40% relative humidity. After mixing evenly, dispense and seal for storage.

[0058] III. Application Methods and Effect Verification 1. Application plan The soil type of the experimental plot was saline-alkali soil. The pathogens of root rot were Fusarium oxysporum and Pythium cerevisiae, with an incidence of 45%. The experimental plot was 667 m².

[0059] 10 days before transplanting: Spread the microbial fertilizer evenly on the soil surface and plow it into the soil. The application rate is 60 kg / 667 m². Initial flowering stage: Apply fertilizer to the root zone at a rate of 45 kg / 667 m². Water promptly after application to promote fertilizer dissolution and root absorption. During the peak fruiting period: Apply fertilizer to the root zone at a rate of 45 kg / 667 m². Water promptly after fertilization to promote fertilizer dissolution and root absorption.

[0060] 2. Effect detection Control group: No microbial fertilizer applied; Experimental group: Microbial fertilizer applied. Okra root rot incidence: 45% in the control group, 5% in the experimental group, with a control rate of 88.9%. Soil pH: 8.5 for the control group and 7.4 for the experimental group. The suitable pH range for okra growth is 6.0 to 7.5. Soil organic matter content: 1.2% in the control group and 2.5% in the experimental group, an increase of 108.3%; Okra single fruit weight: 15g in the control group and 28g in the experimental group, an increase of 86.7%.

[0061] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A microbial fertilizer for preventing and controlling okra root rot, characterized in that: The microbial fertilizer mainly includes: Component 1: Bacillus amyloliquefaciens ( Bacillus amyloliquefaciens ); Component 2: Okra straw fermentation product, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid; Component 3: Composed of a mixture of biomass power plant ash and diatomaceous earth; The weight percentage of each component in the microbial fertilizer is as follows: component 1 accounts for 1% to 5%, component 3 accounts for 10% to 25%, and the remainder is component 2. Furthermore, the preparation method of the microbial fertilizer includes: drying component 2 at 50-60℃ for 2-3 hours, then mixing it with a Bacillus amyloliquefaciens agent of component 1 with a live bacteria content of 1×10¹¹ CFU / g, and stirring evenly using a gradient dilution method to achieve a live Bacillus amyloliquefaciens content of 3×10¹¹ CFU / g in the mixed material. 9 ~6×10 9 CFU / g; then add component 3 to it, and stir for 30-40 minutes at room temperature and relative humidity ≤40% until it is evenly mixed.

2. The microbial fertilizer for preventing and controlling okra root rot as described in claim 1, characterized in that: In component 2, the weight ratio of okra straw fermentation product, konjac glucomannan, shell powder, mineral-derived potassium humate and polyglutamic acid is 58-68:14-18:10-14:4-6:2-4.

3. The microbial fertilizer for preventing and controlling okra root rot as described in claim 1, characterized in that: The preparation method of the okra straw fermented product is as follows: okra straw is crushed to a particle size of 1-3 mm, and a composting agent and brown sugar are added at a mass ratio of 100:5:

3. The composting agent is a compound of Aspergillus oryzae, yeast, and actinomycetes in a ratio of 2:1:

1. The moisture content of the mixture is adjusted to 60%-65%, and aerobic fermentation is carried out at 30-35℃ for 15-20 days, during which the pile is turned 3-4 times. After fermentation, the material is dried to a moisture content of ≤12% and crushed through an 80-mesh sieve. The obtained okra straw fermented product has an organic matter content of ≥50% and a humic acid content of ≥15% on a dry matter basis.

4. The microbial fertilizer for preventing and controlling okra root rot as described in claim 1, characterized in that: The purity of the konjac glucomannan is ≥85%; the shell powder is calcined at 800-900℃ for 2-3 hours and then pulverized through a 100-mesh sieve, wherein the CaCO3 content is ≥90%; the potassium fulvic acid from the mineral source contains ≥55% fulvic acid and ≥35% potassium oxide; and the purity of the polyglutamic acid is ≥90%.

5. The microbial fertilizer for preventing and controlling okra root rot as described in claim 1, characterized in that: In component C, the weight ratio of biomass power plant ash to diatomaceous earth is 3:1; the biomass power plant ash, on a dry matter basis, has a silicate content of 18-22% and a potassium salt content of 4-5%; the diatomaceous earth has a specific surface area ≥200m² / g and a pore size distribution of 20-50nm.

6. The application of the microbial fertilizer as described in any one of claims 1-5 in reducing the content of mycotoxins in the rhizosphere soil of okra, and / or increasing the content of resistance substances in okra roots, and / or preventing okra root rot.

7. The application according to claim 6, characterized in that: The pathogen causing okra root rot is Fusarium oxysporum (Fusarium oxysporum). Fusarium oxysporum Fusarium solani ( ), eggplant skin Fusarium ( Fusarium solani f. sp. melongenae ) and ultimate Pythium ( Pythium ultimum One or more of the following.

8. A method for preventing and controlling okra root rot, characterized in that, Apply the microbial fertilizers described in 1-5 above to the rhizosphere soil of okra, plow them into the soil, and apply at a rate of 50-60 kg / 667 m². Then, apply the fertilizers to the rhizosphere holes at the initial flowering stage and the peak fruiting stage of okra, with an application rate of 40-45 kg / 667 m² each time. Water the soil after application. Apply the fertilizers a total of 3 times throughout the entire growth period.

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