Biological microcapsule formulations, their preparation and use

Abstract

The application discloses a biological microcapsule preparation and a preparation and application thereof, and aims to solve the technical problems of a short shelf life, a great influence of external environmental factors, poor stability and the like of an existing biocontrol preparation. The biological microcapsule preparation is prepared by embedding a pink Clonostachys rosea strain CGMCC No. 16262, spores or / and metabolites thereof with a embedding agent sodium alginate, a filler and an auxiliary agent algal oligosaccharide. The filler is at least one of soluble starch and bentonite. The biological microcapsule preparation has a long shelf life, and can significantly improve the acid and alkali resistance, salt resistance, ultraviolet resistance and high-temperature resistance of the pink Clonostachys rosea strain, and the effects of the biological microcapsule preparation in plant nematode disease prevention and yield increase promotion are significantly higher than those of other dosage forms. In addition, the microcapsule single-dose treatment or the microcapsule reduced-dose compound treatment with trifopyrifenam can significantly improve the control effect on root-knot nematode disease, achieves the purpose of pesticide reduction and efficiency increase, and has a good application prospect.

Description

Technical Field

[0001] This invention application relates to the field of agricultural biological control technology, specifically to a biological microcapsule bacterial preparation and its preparation and application. Background Technology

[0002] Root-knot nematodes ( Meloidogyne Root-knot nematodes (S. sp.) are a globally distributed plant parasitic nematode that can infect more than 3,000 plant species, including various field crops, vegetables, trees, and garden flowers. Global losses due to plant parasitic nematodes reach as high as US$100 billion annually, posing a serious threat to global agricultural security. Root-knot nematodes primarily infect plant roots, forming root knots or galls, disrupting root tissue differentiation and physiological activities, leading to poor plant development and premature aging. The wounds caused by root-knot nematodes can also promote the occurrence of soil-borne fungal diseases such as root rot and wilt, as well as some bacterial diseases. Root-knot nematode disease generally leads to a 20%–30% reduction in vegetable yields, and in severe cases, up to 90%, becoming a major obstacle to the sustainable development of greenhouse vegetables worldwide. In recent years, due to the rapid development of my country's agricultural economy, industrial restructuring and adjustments, the shift from monoculture to greenhouse cultivation, and the rapid increase in greenhouse planting area, the incidence of root-knot nematode disease has shown a trend of increasing severity year by year, becoming a significant threat to my country's agricultural production.

[0003] Currently, chemical control is the primary method for nematode control in production. However, due to the high toxicity of traditional chemical nematicides, relatively high control costs, and the potential for pollution and resistance, their use is gradually being restricted. There is an urgent need to find environmentally friendly alternatives. Biological control, as a safe and effective method, has been widely researched and applied in the control of plant pathogenic nematodes. This control method aligns with the needs of sustainable agricultural development and green plant protection concepts, serving as a crucial means to ensure high-quality and high-yield agriculture in modern agriculture, and an effective way to achieve "reduced application and increased efficiency" of pesticides. Therefore, the development of new green, safe, and highly efficient biological control agents is imperative.

[0004] Pink broom mold ( Clonostachys rosea *Aspergillus oryzae*, also known as pink spiral *Aspergillus*, is a particularly important biocontrol resource for plant diseases due to its rapid growth, high sporulation rate, and diverse mechanisms of action. Although numerous *Aspergillus oryzae* strains with biocontrol potential have been studied and reported, only a few strains are currently produced as commercial formulations, with most remaining in the laboratory research and development stage and unable to be widely applied. Furthermore, the survival and dominant population formation of the strains in complex soil environments after application is crucial for the biocontrol agent to exert its growth-promoting effect. Existing biocontrol formulations in production generally suffer from short shelf life, high susceptibility to external environmental factors, and poor stability.

[0005] The information disclosed in this Background section is only for the purpose of enhancing the understanding of the background of the present disclosure and should not be taken as admitting that this information is prior art nor that this information in any form implies that it is known. SUMMARY

[0006] The inventors have found that the existing biocontrol agents on the market generally have a short shelf life, are greatly affected by external environmental factors, and have poor stability of efficacy. However, the use of certain microencapsulation embedding processes can effectively avoid the direct impact of adverse environmental factors on the bacteria, has a slow release characteristic, can effectively improve the survival rate and persistence of the bacteria, and can enable the bacteria to stably colonize in the soil and fully exert the efficacy of the bacteria. Moreover, the prepared microcapsule preparation has a long shelf life, and the embedded Gliocephalum pastillicum CGMCC No. 16262 has good acid and alkali resistance, salt tolerance, ultraviolet resistance, and high temperature resistance, and plays an important role in the prevention and control of plant nematode diseases and the promotion of crop growth and yield, either alone or in a reduced amount of trifopyr.

[0007] In one aspect of the present disclosure, a biological microcapsule preparation is provided, which is prepared from an embedding agent, a filler embedding Gliocephalum pastillicum CGMCC No. 16262, spores or / and metabolites thereof, and an auxiliary agent. The embedding agent is sodium alginate, the filler is at least one of soluble starch and bentonite, and the auxiliary agent is sea algal oligosaccharide.

[0008] In some embodiments of the present disclosure, the content of bacteria in the biological microcapsule preparation is (3-9) x 10 8 CFU / g.

[0009] In some embodiments of the present disclosure, the biological microcapsule preparation contains 2% of sodium alginate, 3% of starch, and 3% of bentonite by mass fraction.

[0010] According to another aspect of the present disclosure, a preparation method of a biological microcapsule preparation is provided, which comprises the following steps:

[0011] (1) A fresh Gliocephalum pastillicum NF-06 strain CGMCC No. 16262 cake is inoculated into a PDB liquid medium, and is shaken and cultured at 26-28°C for 2-3 days in a shaking bed to obtain a seed liquid;

[0012] (2) The seed liquid is inoculated into a fermentation medium at a weight ratio of 1%-2%, and is shaken and cultured at 26-28°C for 2-4 days in a shaking bed to obtain a fermentation liquid. The fermentation medium contains, by weight, corn powder 5%, shrimp powder 1%, sucrose 0.5%, zinc sulfate 0.1%, and potassium dihydrogen phosphate 0.2%, and has a pH of 7.0-8.0;

[0013] (3) The mycelium and medium impurities are filtered out with sterile double-layer gauze to obtain a free bacteria culture;

[0014] (4) adding a sodium alginate solution into the fermentation filtrate to obtain a mixed solution;

[0015] (5) adding a filler and an auxiliary into the mixed solution, and then adding a CaCl2 solution to cross-link and solidify to obtain the microcapsule preparation.

[0016] According to still another aspect of the present disclosure, a compounded pesticide is provided, wherein the effective components are composed of the biological microcapsule preparation and triflumezopyrim at a mass ratio of 1000:2-3.

[0017] According to still another aspect of the present disclosure, the biological microcapsule preparation is used alone or compounded with triflumezopyrim to be applied in the prevention and / or treatment of plant nematode diseases.

[0018] The plant nematode diseases include wheat cyst nematode disease, crop root knot nematode disease or crop root rot nematode disease.

[0019] According to another aspect of the present disclosure, a method for preventing plant nematode diseases is provided, wherein the biological microcapsule preparation is hole-applied at 1-2 g / plant, and 450 g / L triflumezopyrim suspension is root-applied at 0.004-0.008 mL / plant when the plant seedlings are transplanted.

[0020] The one or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects or advantages:

[0021] 1. The microcapsule preparation contains Lecanicillium persoonii CGMCC No. 16262, its conidium and secondary metabolites, and has high bacteria content and high bacteria activity, is safe and non-toxic to use, and has stable and reliable prevention effect, compared with conventional powder. Compared with the NF-06 solid fermentation bacteria in CN109762743B and the free bacteria of the NF-06 strain, the microcapsule preparation significantly improves the prevention effect of the strain on root knot nematode disease.

[0022] 2. The microcapsule preparation prepared by the method has a long shelf life, and can significantly improve the acid and alkali resistance, salt tolerance, ultraviolet resistance and high temperature resistance of Lecanicillium persoonii.

[0023] 3. The microcapsule preparation has good disease prevention and growth promotion effects. For example, when applied to tomato seedlings, the prevention effect on tomato root knot nematode is significantly improved (up to 70.7%), and the prevention effect of the reduced amount of triflumezopyrim reaches 78.9%, achieving the effect of reducing the amount and increasing the efficiency, and significantly increasing the root length, plant height and fresh weight of tomato plants, and having a significant growth promotion effect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1This is a shelf-life stability trend diagram of a biological microcapsule formulation in one embodiment of this application.

[0025] Figure 2 This is a bar chart comparing the salt tolerance of the biological microcapsule formulation in one embodiment of this application.

[0026] Figure 3 This is a bar chart comparing the acid and alkali resistance of the biological microcapsule formulation in one embodiment of this application.

[0027] Figure 4 This is a graph showing the trend of the UV resistance of the biological microcapsule formulation in one embodiment of this application.

[0028] Figure 5 This is a bar chart comparing the high-temperature resistance of the biological microcapsule formulation in one embodiment of this application. Detailed Implementation

[0029] The specific implementation of this application is described below with reference to the embodiments. However, the following embodiments are only used to illustrate the present invention in detail and do not limit the scope of this application in any way.

[0030] Unless otherwise specified, the instruments and equipment involved in the following embodiments are all conventional instruments and equipment; the biochemical reagents and test materials involved are all commercially available products unless otherwise specified; and the test methods involved are all conventional methods unless otherwise specified.

[0031] Example 1: Preparation of concentrated fermentation product of *Pseudomonas erythrosporum*

[0032] The strain used in this embodiment is *Pseudomonas pulvinata*. Clonostachys rosea The NF-06 strain has the accession number CGMCC No.16262 (see CN109762743B).

[0033] The strain was inoculated onto PDA plates and cultured at 25°C for 5 days. Mycelial cakes were then collected from the edges of the colonies using a punch. Three mycelial cakes were inoculated into each 100 mL of PDB medium and shaken at 28°C and 180 rpm for 3 days to obtain a seed culture. This seed culture was then inoculated at a weight ratio of 1% into a fermentation medium (containing, by weight: 5% corn flour, 1% shrimp meal, 0.5% sucrose, 0.1% zinc sulfate, 0.2% potassium dihydrogen phosphate, pH 7.0–8.0) and cultured at 26–28°C in a shaker for 3 days to obtain a fermentation broth. Mycelia were filtered out using sterile double-layered gauze to obtain the *Pseudomonas pulvinata* ferment.

[0034] Example 2: Optimal Validation Test of Packing Material Formulation

[0035] Under the conditions of 30% inoculation amount, 2% sodium alginate concentration, 0.5% oligosaccharide concentration, 3% CaCl2 concentration, and 24 h cross-linking and curing time, different concentrations of starch and bentonite were added, the microcapsule bacterial content (placed at room temperature for 30 d) was used as the response index, and the single factor method was used to screen the filler formula of the microcapsule.

[0036] The results showed (Table 1) that compared with the control, the addition of different concentrations of starch and bentonite could significantly increase the bacterial content and embedding rate of the G. roseum microcapsule preparation, and the embedding rates were 75.0%, 75.0%, and 77.8% when 2%, 5%, and 10% starch was added, respectively. However, the more starch was added, the more bubbles were produced in the microcapsule preparation. When 3%, 6%, and 10% bentonite was added, the embedding rates were 77.8%, 83.3%, and 86.1%, respectively. However, the more bentonite was added, the greater the operating mechanical strength was, and the spheroidization was poor. Therefore, 2% starch and 3% bentonite were selected as the basis for the inoculation amount in the next orthogonal experiment.

[0037] .

[0038] Note: Operability: “+++” indicates that the operating mechanical strength is particularly large; “++” indicates that the operating mechanical strength is relatively large; “+” indicates that the operating mechanical strength is moderate. Bubbles: “+++” indicates that a large number of bubbles are produced in the microcapsule; “++” indicates that a small amount of bubbles are produced; “+” indicates that a trace amount of bubbles are produced; “-” indicates that no bubbles are produced. Spheroidization uniformity: “+++” indicates that the spheroidization is good, without trailing and adhesion; “++” indicates that the spheroidization is relatively good, without trailing, and a small amount of adhesion; “+” indicates that the spheroidization is relatively poor, with trailing and adhesion. Capsule breakage rate: “+++” indicates that the microcapsule is quickly dissolved in the sodium citrate buffer; “++” indicates that the microcapsule is slowly dissolved in the sodium citrate buffer; “+” indicates that the microcapsule is particularly slowly dissolved in the sodium citrate buffer.

[0039] Example Three, Optimization Verification Test of Microcapsule Embedding Wall Material

[0040] Under the conditions of 30% inoculation amount, 0.5% oligosaccharide, and 3% CaCl2 concentration, and 24 h cross-linking and curing time, the embedding rate of the microsphere was used as the response index, and the optimal ratio of sodium alginate, bentonite, and starch was optimized. A three-factor and three-level response surface optimization test was carried out (Table 2), a mathematical model between the complex wall material ratio and the embedding rate was established, and a response surface analysis was carried out, so as to determine the optimal embedding wall material ratio of the G. roseum microcapsule.

[0041] .

[0042] .

[0043] Note: K1, K2 and K3 are the average values of each factor at each level; R represents the range.

[0044] The orthogonal test results show (Table 3) that the factors affecting the spore embedding rate of L. roseum microcapsules are in the order of sodium alginate > starch > bentonite, and the optimal combination is sodium alginate 2%, starch 3% and bentonite 3%. It is verified that when the sodium alginate dosage is 2%, the starch dosage is 3% and the bentonite dosage is 3%, the microcapsule preparation contains 6.7 x 10 8 CFU / g, and the embedding rate reaches 95.7%.

[0045] Example Four, Shelf Life Stability Verification Test of L. roseum Microcapsule Preparation

[0046] The prepared microcapsules and free NF-06 bacterial solution were stored at 25°C, and the viable cell count was determined once every 20 days for a total of 60 days. The shelf life stability of L. roseum microcapsules was evaluated.

[0047] The changes in viable cell count of L. roseum microcapsules and free bacteria during storage at 25°C for 60 days are shown in Table 4. Figure 1 At 0 days, the viable cell counts of microcapsules and free bacteria were 6.11 x 10 8 CFU / g and 6.60 x 10 8 CFU / g, respectively. As time increased, the viable cell count in microcapsules decreased slowly, while the viable cell count in free bacteria decreased rapidly. The decrease rate of viable cell count in free bacteria was significantly higher than that in encapsulated bacteria. After 60 days of storage at room temperature, the viable cell count of microcapsules was 9.97 x 10 7 CFU / g, which decreased by one order of magnitude; while the viable cell count of free bacteria was 5.63 x 10 5 CFU / g, which decreased by three orders of magnitude. It can be seen that microencapsulation can indeed improve the shelf life of L. roseum.

[0048] Example Five, Salt Tolerance Verification Test of L. roseum Microcapsules

[0049] NaCl solution was added to PDB medium to a final concentration of 0%, 1%, 2% and 3%, respectively. Equal amounts of microcapsule bacteria and free NF-06 bacterial solution were added to 10 mL of PDB solution with different NaCl concentrations, and incubated at 25°C, 160 rpm for 48 h. Then, the viable cell count in the free bacterial culture was determined by plate coating method. The microcapsules were filtered out, the surface moisture was absorbed with sterile filter paper, 10 mL of citrate buffer was added to dissolve the microcapsules, and plate counting was used to determine the salt tolerance of L. roseum microcapsule preparation.

[0050] The results show (Table 5) Figure 2), the viable cell number of the microcapsule and the free NF-06 bacteria liquid in the PDB medium containing 1% NaCl was the most, which was 3.53 x 10 7 CFU / mL and 3.27 x 10 7 CFU / mL, respectively, and there was no significant difference between them. However, when the NaCl concentration in the PDB was 2% and 3%, respectively, the viable cell number of the microcapsule after culture was 2.87 x 10 7 CFU / mL and 1.47 x 10 7 CFU / mL, and the viable cell number of the free bacteria was 2.03 x 10 7 CFU / mL and 0.47 x 10 7 CFU / mL, respectively. The viable cell number of the free bacteria was significantly lower than that of the microcapsule. Therefore, the microcapsule dosage form can significantly increase the salt tolerance of the G. roseum strain.

[0051] Example Six, Verification Test of Acid and Alkali Resistance of G. roseum Microcapsule

[0052] The PDB medium with pH values of 4.0, 5.0, 6.0, 7.0, 8.0, 9.0 and 10.0 was configured, and the determination method was as above to determine the acid and alkali resistance of the microcapsule preparation.

[0053] The results show that (Table 6) Figure 3 ), when the pH of the PDB culture solution was 7, the viable cell number of the microcapsule and the free bacteria liquid was the most, which was 32.67 x 10 7 CFU / mL and 33.33 x 10 7 CFU / mL, respectively, and there was no significant difference between them; when the pH was 6, the viable cell number of the microcapsule and the free bacteria liquid was 28.33 x 10 7 CFU / mL and 28.33 x 10 7 CFU / mL, respectively, and there was no significant difference between them. However, when the pH was less than 5 or greater than 8, the viable cell number of the microcapsule and the free bacteria was significantly reduced, indicating that the pH value had an important influence on the activity of the bacteria. In addition, when the pH was 5, 8, 9 and 10, the viable cell number of the microcapsule was significantly higher than that of the free bacteria, indicating that the microcapsule dosage form could significantly increase the acid and alkali resistance of the G. roseum.

[0054] Example Seven, Verification Test of UV Irradiation Resistance of G. roseum Microcapsule

[0055] The prepared microcapsule and the free NF-06 bacteria liquid were respectively placed under a wide-wavelength ultraviolet lamp for 0 h, 0.5 h, 1 h, 2 h, 3 h, 6 h, 12 h and 24 h to determine the viable cell number, and the strain stored in the dark under the same conditions was used as a control to evaluate the UV radiation resistance of the microcapsule.

[0056] The results show that (Table 1) Figure 4 , the viable cell counts of free bacteria and microcapsules are 6.61 x 10 8 CFU / g and 6.39 x 10 8 CFU / g respectively at 0 h of UV irradiation, while the viable cell count of free bacteria is 0 and that of microcapsules is 5.76 x 10 8 CFU / g after 0.5 h of UV irradiation. Although the viable cell count of microcapsules gradually decreases with the increase of UV irradiation time, the viable cell count of microcapsules is still 2.60 x 10 8 CFU / g after 24 h of UV irradiation. It is shown that the microcapsule dosage form can significantly increase the ability of the strain of G. roseum to resist UV radiation.

[0057] Example Eight, verification test of high temperature resistance of the microcapsules of G. roseum

[0058] The prepared microcapsules and free NF-06 bacterial solution were respectively placed in 25℃, 30℃, 35℃ and 40℃ incubators for storage for 7 days, and then the viable cell count was determined to evaluate the high temperature resistance of the microcapsules.

[0059] The results show that (Table 2) Figure 5 , the viable cell counts of microcapsules and free bacteria gradually decrease with the increase of storage temperature. Among them, there is no significant difference in the colony forming units of microcapsules and free bacteria after being stored in a 25℃ incubator for 7 days, which are 6.29 x 10 8 CFU / g and 5.93 x 10 8 CFU / g respectively. However, the viable cell count of microcapsules is significantly higher than that of free bacteria when stored in 30℃, 35℃ and 40℃ incubators. Among them, the viable cell counts of microcapsules and free bacteria are 5.01 x 10 8 CFU / g and 4.32 x 10 8 CFU / g respectively under the storage condition of 30℃; the viable cell counts of microcapsules and free bacteria are 2.53 x 10 8 CFU / g and 0.53 x 10 8 CFU / g respectively under the storage condition of 35℃; and the viable cell count of microcapsules is 2.19 x 10 8 CFU / g, while the viable cell count of free bacteria is 3.33 x 10 3 CFU / g under the storage condition of 40℃. It can be seen that the microcapsule dosage form obtained by the present application can significantly enhance the high temperature resistance of G. roseum.

[0060] Example Nine, verification test of the control effect of the microcapsules of G. roseum on tomato root-knot nematodes

[0061] The test grouping treatment is as follows:

[0062] Treatment 1: Pink Gliocladium microcapsules prepared in Example 3, 1 g / plant hole application at the time of tomato seedling transplanting;

[0063] Treatment 2: Pink Gliocladium microcapsules prepared in Example 3, 2 g / plant hole application at the time of tomato seedling transplanting;

[0064] Treatment 3: Pink Gliocladium microcapsules prepared in Example 3, 1 g / plant hole application at the time of tomato seedling transplanting; at the same time, 450 g / L triforine suspension agent, 0.006 mL / plant root irrigation at the time of transplanting;

[0065] Treatment 4: 450 g / L triforine suspension agent, 0.012 mL / plant root irrigation at the time of tomato seedling transplanting;

[0066] Treatment 5: According to CN109762743B, prepare Gliocladium roseum strain NF-06 solid fermentation agent, 2 g / plant hole application at the time of tomato seedling transplanting;

[0067] Treatment 6: Free Gliocladium roseum bacteria prepared in Example 1, 20 mL / plant root irrigation at the time of tomato seedling transplanting;

[0068] Treatment 7: 0.5% abamectin granules, 2 g / plant hole application;

[0069] Treatment 8: Control.

[0070] Each group has 9 plants, after 45 days of transplanting, the root knot situation and the physiological indexes of tomato such as plant height and underground fresh weight are investigated, and the root knot index and control effect are calculated according to the grading standard.

[0071] The calculation formula of root knot index and control effect is:

[0072] Root knot index = Σ (number of plants of each level x level) / total number of plants investigated;

[0073] Control effect (%) = (control root knot index - control root knot index) / control root knot index x 100.

[0074] Among them, the grading standard of level is:

[0075] 0 level, healthy root system, no root knot; 1 level, very few root knots, root knot rate is 1% to 20%; 2 level, less root knots, root knot rate is 21% to 40%;

[0076] 3 level, moderate number of root knots, root knot rate is 41% to 60%; 4 level, a large number of root knots, 61% to 80% of root system has root knot;

[0077] 5 level, root knots are connected into root knot clumps, more than 81% of root system has root knot.

[0078] The test results are shown in Table 4.

[0079] .

[0080] As can be seen from Table 4, the control effect of microcapsules 2 g / plant on tomato root-knot nematode disease is 70.7%, close to 71.7% of the control effect of 0.5% abamectin 2 g / plant hole treatment; the control effect of microcapsules 1 g / plant on tomato root-knot nematode disease is 56.7%, and the control effect of microcapsules + trifopyr 1 g+0.006 mL / plant reduced amount compound treatment on tomato root-knot nematode disease is 72.0%, close to 74.0% of trifopyr 0.012 mL / plant treatment, so the combination has good reduced amount and synergistic effect. In addition, the control effect of the pink gongylus striatus strain NF-06 solid fermentation microbial agent 2 g / plant prepared in CN109762743B on tomato root-knot nematode disease is 59.4%; the control effect of free bacteria 20 mL / plant on root-knot nematode disease is 53.1%, so the application of microcapsule dosage form significantly improves the control effect of the strain on root-knot nematode disease, and the control effect of the dosage form on root-knot nematode disease is better than that of other dosage forms, and has good application prospect.

[0081] In addition, the root length, plant height and fresh weight of tomato plants treated with NF-06 microcapsules 2 g / plant are higher than those of other treatments, so the dosage form has a significant growth-promoting effect.

Claims

1. A biologic microencapsulated formulation, characterized in that, The biological microcapsule preparation is prepared from pink Clonostachys rosea CGMCC No. 16262, spores or / and metabolites thereof, embedding agent sodium alginate, filler and adjuvant soluble starch and bentonite; the preparation method comprises the following steps: 1) inoculate the pink Clonostachys rosea CGMCC No. 16262 strain into PDB liquid medium, and shake culture at 26-28 DEG C in a shaker for 2-3 days to obtain a seed liquid; 2) inoculate the seed liquid into a fermentation medium according to a weight ratio of 1%-2%, and shake culture at 26-28 DEG C in a shaker for 2-4 days to obtain a fermentation liquid; the fermentation medium contains corn powder 5%, shrimp powder 1%, sucrose 0.5%, zinc sulfate 0.1%, potassium dihydrogen phosphate 0.2% by weight, and pH is 7.0-8.0; 3) filter out mycelium and medium impurities to obtain a free bacteria culture; 4) add a sodium alginate solution to the free bacteria culture to obtain a mixed solution; 5) further add fillers and adjuvants to the mixed solution, and cross-link and solidify in a CaCl2 solution to obtain a microcapsule preparation; wherein the percentage of inoculation amount is 30%, the concentration of CaCl2 is 3%, the concentration of sodium alginate is 2%, the concentration of starch is 3%, the concentration of bentonite is 3%, and the concentration of soluble oligosaccharide is 0.5%.

2. The biological microencapsulation formulation according to claim 1, wherein, The bacterial content thereof is (3-9) x 10 8 CFU / g.

3. The biological microencapsulation formulation according to claim 1, wherein The cross-linking and solidification time is 24 h.

4. A compound pesticide, wherein the effective components are composed of the biological microcapsule preparation of claim 1 and trifopyrifene according to a mass ratio of 1000:2-3.

5. The biological microcapsule preparation of claim 1 or the compound pesticide of claim 4 is applied in the prevention and / or treatment of plant nematode diseases.

6. Use according to claim 5, characterized in that, The plant nematode diseases are wheat cyst nematode disease, crop root knot nematode disease or crop root rot nematode disease.

7. A method of controlling nematode disease of plants, characterized by, When the plant seedlings are transplanted, 1-2 g of the biological microcapsule preparation of claim 1 is hole-applied per plant, or the biological microcapsule preparation of claim 1 and 450 g / L trifopyrifene suspension agent 0.004-0.008 mL per plant are jointly applied.

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