A microbial agent for preventing root-knot nematode disease and clubroot disease and its application

Abstract

The invention discloses a microbial agent for preventing root-knot nematode disease and root-root disease and its application, relates to the field of fertilizers, solves the technical problems in the prior art that the field symptoms of root-knot nematode disease and root-root disease are similar and difficult to quickly distinguish and accurately select agents, and that root-knot nematode disease and root-root disease are easy to occur at the same time and difficult to prevent and control in time. The microbial agent for preventing root-knot nematode disease and root-root disease of the present invention is a composite agent prepared by compounding the bacterial powders of methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis. The microbial agent for preventing root-knot nematode disease and root-root disease of the present invention, the three strains are compounded and used, can achieve effective prevention and control of root-root disease, activation of soil nutrients and promotion of crop root system in the early stage of use, and then can effectively inhibit root-knot nematodes, and further promote the growth and development of crop root system, enhance the nutrient absorption of crops after effective prevention and control of diseases, and further reduce the yield loss of crops caused by diseases.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a microbial agent capable of preventing both root-knot nematode disease and clubroot disease and application thereof. Background Art

[0002] With the rise of organic agriculture, green control methods are increasingly used in agriculture, among which the use of microorganisms for disease control is a more commonly used and effective technical means. However, in current agricultural disease control, a biological control product generally only works on one disease. If the type of disease cannot be accurately identified when used in the field, it is often impossible to accurately prevent and control the disease, especially for diseases with similar symptoms. If there is no rapid field detection technology at present, it often results in the wrong selection of agents and delays in prevention and control.

[0003] Based on current field identification and detection methods, cruciferous clubroot and root-knot nematode diseases cannot be quickly identified and detected in the field. When root-knot nematode diseases occur in the roots of cruciferous vegetables, the symptoms of the above-ground parts are extremely similar to those of clubroot, both of which cause the plants to grow slowly. Therefore, when cruciferous vegetables develop nodules, they can only be distinguished by dissecting the tumors or root knots at the roots, and judging whether there are adult milky white pear-shaped root-knot nematodes in the tumors. This is currently the most accurate basis for judgment, but it requires certain instruments and testing time, and rapid field detection is currently not possible.

[0004] Due to the different pathogens and conditions of the two diseases, the current prevention and control methods for the two diseases in agricultural production are very different. Correct diagnosis of clubroot and root-knot nematode disease is very important for their prevention and control. According to market surveys, there are currently no good biological control products for the two diseases, and chemical control is mainly used in actual production. Clubroot disease is mainly treated with 15% 500 times dilution of oxadone aqueous solution or 70% methyl thiophanate wettable powder 600 times dilution for root irrigation, once every 7 days, 2 to 3 times in a row; in the early stage of root-knot nematode disease, 1.8% avermectin emulsifiable concentrate 2000 times dilution, 50% phoxim emulsifiable concentrate 1800 times dilution, 90% trichlorfon crystals 800 times dilution or 80% dichlorvos emulsifiable concentrate 1000 times dilution can be used for root irrigation, with 0.2 to 0.3 kg of liquid per plant. In the vegetable growing season, 1% Haizheng insecticide emulsifiable concentrate 80 times dilution can also be used for soil surface spraying. Based on the above prevention and control measures, it can be seen that rapid and accurate identification of diseases is very important. If the diseases cannot be correctly identified, it is impossible to accurately select the pesticides.

[0005] At the same time, in actual production, the occurrence of root-knot nematode disease will reduce plant resistance, often leading to the simultaneous occurrence of clubroot disease. When the two occur at the same time, it is often more difficult to prevent and control. Because the control agents for the two diseases are completely different, if only a single disease is controlled, the symptoms of the disease cannot be improved at all. Once the two diseases occur together, it means that the production of vegetables in the season will be lost, causing huge losses to farmers. Therefore, how to carry out comprehensive prevention and control of the two diseases is a technical problem that needs to be solved urgently in current agricultural production.

[0006] In view of the similarities in the field symptoms of the two diseases, the differences in prevention and control methods, and the possibility of simultaneous occurrence in cruciferous vegetables, there is an urgent need for a product that can prevent and control both diseases, while avoiding the technical difficulty of quickly distinguishing the two diseases in the field, so as to effectively prevent and control the two diseases. Summary of the invention

[0007] The purpose of the present invention is to provide a microbial agent for preventing both root-knot nematode disease and clubroot disease and its application, which solves the technical problems in the prior art that the field symptoms of root-knot nematode disease and clubroot disease are similar and difficult to quickly distinguish and accurately select agents, and that root-knot nematode disease and clubroot disease are prone to occur simultaneously and difficult to prevent and control in time. The many technical effects that can be produced by the preferred technical scheme of the present invention are described in detail below.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] The microbial agent for preventing both root-knot nematode disease and clubroot disease comprises the following strains: methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis, and the microbial agent is a composite agent prepared by compounding the bacterial powders of methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis.

[0010] The methylotrophic bacillus (Bacillus methylotrophicus) of the present invention is numbered WSWFJ-29, the deposit registration number is CGMCC No.18269, the deposit date is July 22, 2019, the deposit unit is the General Microbiological Center of the China Microbiological Culture Collection Administration, and the deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. Morphological characteristics of methylotrophic bacillus WSWFJ-29: under dark conditions, after culturing on LB medium for 3 days, milky white round colonies appear, the surface and edges are rough, wrinkled, the colonies are translucent, and relatively thick.

[0011] The Paecilomyces lilacinus of the present invention is numbered WSWFJ-28, the deposit registration number is CGMCC No.18274, the deposit date is July 22, 2019, the deposit unit is the General Microbiological Center of the China Microbiological Culture Collection Administration, and the deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. Morphological characteristics of Paecilomyces lilacinus WSWFJ-28: under dark conditions, white round colonies grow after 3 days of culture on a PDA plate, and gradually turn light pink after spore production. After 7 days of culture, the colonies are purple, round, raised, and powdery, with no secretions on the surface. The more spores are produced, the darker the color of the colonies.

[0012] The Bacillus subtilis of the present invention is numbered WSWFJ44, the deposit registration number is CGMCC No. 20144, the deposit date is June 28, 2020, the deposit unit is the General Microbiology Center of the China Microbiological Culture Collection Administration, and the deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. Bacillus subtilis WSWFJ44 morphological characteristics: under dark conditions, after culturing on LB medium for 3 days, it presents slightly yellow colonies, the colonies are irregular in shape, the surface of the colonies is rough and wrinkled, the colonies are opaque, and relatively thick.

[0013] According to a preferred embodiment, the effective viable count of methylotrophic Bacillus and Bacillus subtilis is not less than 1×10 11 CFU / g of Bacillus microbial powder; the spore quantity of Paecilomyces lilacinus reached 1×10 10 CFU / g of Paecilomyces lilacinus spore powder.

[0014] According to a preferred embodiment, methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are compounded in the following weight proportions: 3-8 parts of methylotrophic Bacillus powder, 1 part of Paecilomyces lilacinus spore powder and 2-5 parts of Bacillus subtilis powder.

[0015] According to a preferred embodiment, methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are compounded in the following weight proportions: 3 parts of methylotrophic Bacillus powder, 1 part of Paecilomyces lilacinus spore powder and 5 parts of Bacillus subtilis powder.

[0016] According to a preferred embodiment, methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are compounded in the following weight proportions: 8 parts of methylotrophic Bacillus powder, 1 part of Paecilomyces lilacinus spore powder and 2 parts of Bacillus subtilis powder.

[0017] According to a preferred embodiment, methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are compounded in the following weight proportions: 5 parts of methylotrophic Bacillus powder, 1 part of Paecilomyces lilacinus spore powder and 4 parts of Bacillus subtilis powder.

[0018] Application of the microbial agent for preventing both root-knot nematode disease and clubroot disease as described in any technical solution of the present invention in the cultivation of cruciferous plants.

[0019] According to a preferred embodiment, the methylotrophic Bacillus powder, the Paecilomyces lilacinus spore powder and the Bacillus subtilis powder are packaged and stored separately and mixed when used.

[0020] According to a preferred embodiment, the methylotrophic Bacillus powder, the Paecilomyces lilacinus spore powder and the Bacillus subtilis powder are mixed and used within 48 hours.

[0021] According to a preferred embodiment, the microbial agent is applied to crops by one or more methods of root dipping, root irrigation, pouring, and hole application; or the microbial agent is combined with a matrix and a fertilizer to form a functional seedling matrix and a biological fertilizer for use.

[0022] The microbial agent for preventing both root-knot nematode disease and clubroot disease provided by the present invention and its application have at least the following beneficial technical effects:

[0023] The microbial agent for preventing both root-knot nematode disease and root-swelling disease of the present invention comprises the following strains: methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis, and the microbial agent is a composite agent prepared by compounding the bacterial powders of methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis. After the microbial agent is used and introduced into the soil or substrate, under suitable conditions, the methylotrophic Bacillus with the function of preventing and controlling root-swelling disease and the Bacillus subtilis with the function of activating the soil and inhibiting soil-borne diseases rapidly germinate and reproduce within 1 to 2 days, forming colonization of Bacillus species in the soil, and entering the inside of the crop through the root system of the crop to become endophytic bacteria of the crop. The methylotrophic Bacillus in the soil and inside the crop It can inhibit and kill Brassica root knot fungus, Bacillus subtilis can activate nutrients in the soil and stimulate the growth of crop roots to improve the crop's absorption and utilization of water and fertilizer in the soil, and promote the improvement of crop resistance; and the spores of Paecilomyces lilacinus, which has the function of preventing and controlling root-knot nematode disease, can reproduce into vegetative mycelium within 3 to 5 days, parasitize in the eggs of root-knot nematodes, and effectively kill the nematodes. At the same time, the fungus can produce rich derivatives, one of which is a product similar to indoleacetic acid. Its most significant physiological effect is to promote the growth of plant roots and plants at low concentrations. Therefore, applying the fungus to the plant root system can not only significantly inhibit nematode infection, but also promote the growth of the plant's vegetative organs, and at the same time it also promotes the germination and growth of seeds.

[0024] The present invention is a microbial agent for preventing both root-knot nematode disease and root-root disease. The three strains are compounded for use. Effective prevention and control of root-knot disease, activation of soil nutrients and promotion of crop root system can be achieved in the early stage of use. Subsequently, root-knot nematodes can also be effectively inhibited, and the growth and development of crop root system can be further promoted. After the disease is effectively prevented and controlled, the nutrient absorption of crops is enhanced, and the yield loss of crops caused by diseases is further reduced. The present invention is a microbial agent for preventing both root-knot nematode disease and root-root disease. According to the characteristics of the occurrence of these two diseases and the early characteristics that are difficult to distinguish, the two diseases are prevented and controlled in an integrated manner, and the technical problem that chemical agents cannot be used to prevent and control the two diseases in an integrated manner is completely solved. The present microbial agent is used for prevention and control. Whether it is a single disease of root-knot nematode disease and root-knot nematode disease, or both diseases occur at the same time, effective prevention and control can be carried out, and the problem of difficulty in rapid detection and distinction of the two diseases in field production is avoided. It not only guarantees the requirements of rapid prevention and control and early prevention and control in agricultural production, but also avoids the pollution and residue caused by the abuse of pesticides. It is an economical, fast, effective, green and healthy new prevention and control mode.

[0025] The microbial agent of the present invention for preventing both root-knot nematode disease and clubroot disease is a relatively novel biological control technology for promoting synergistic effects between bacterial species. It provides a technical idea for the coordinated use of functional bacterial agents in the future, points out the technical direction, and has strong technical innovation and good application and promotion value.

[0026] In addition, the preferred technical solution of the present invention can also produce the following technical effects:

[0027] The preferred technical solution of the present invention is to package and store the methylotrophic Bacillus powder, the spore powder of Paecilomyces lilacinus and the Bacillus subtilis powder separately, mix them when in use, and use them within 48 hours after mixing, so as to avoid the problem that the three kinds of bacterial powders influence each other due to too long mixing time, resulting in a reduction in the number of effective live bacteria and affecting the control effect. DETAILED DESCRIPTION

[0028] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0029] The microbial agent for preventing both root-knot nematode disease and clubroot disease and its application are described in detail below in conjunction with Examples 1 to 3.

[0030] Example 1

[0031] This embodiment provides a microbial agent for preventing both root-knot nematode disease and clubroot disease and a method for directly applying the microbial agent.

[0032] The microbial agent for preventing root-knot nematode disease and root-swelling disease in the present invention is prepared by compounding the powders of three strains: methylotrophic Bacillus WSWFJ-29 (with a deposit registration number of CGMCC No. 18269), Paecilomyces lilacinus WSWFJ-28 (with a deposit registration number of CGMCC No. 18274), and Bacillus subtilis WSWFJ44 (with a deposit registration number of CGMCC No. 20144). The effective viable count of methylotrophic Bacillus and Bacillus subtilis is not less than 1×10 11 CFU / g of Bacillus microbial powder, and the spore quantity of Paecilomyces lilacinus reached 1×10 10 CFU / g of Paecilomyces lilacinus spore powder. Methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are physically mixed in the proportions of 3 parts, 1 part and 5 parts by weight respectively, and the microbial agent for preventing root-knot nematode disease and clubroot disease is obtained after mixing evenly.

[0033] Further: The three types of bacterial powders should be packaged separately and mixed when used. They should be used within 48 hours after mixing to avoid mutual influence between the strains due to long mixing time, which will lead to a reduction in the number of effective live bacteria.

[0034] The microbial agent for preventing both root-knot nematode disease and clubroot disease of the present invention can be applied to crops by one or more methods of root dipping, root irrigation, pouring, and hole application. The specific use method is as follows:

[0035] (1) Root dipping: Dilute the microbial agent and water in a weight ratio of 1:500 in clean water to make a diluted agent solution. Dip the roots of the crops when transplanting. The specific method is to soak the crop roots in the diluted agent solution for 1 to 3 seconds and then plant them in the soil. The planting method is the same as conventional operations.

[0036] (2) Root irrigation: Dilute the microbial agent and water in a weight ratio of 1:500 in clean water to make a diluted agent solution. After the crop seedlings are transplanted into the soil, irrigate the roots of each crop near the root system. The specific method is to use 5 to 10 ml of the diluted agent solution to irrigate the soil near the roots of the seedlings.

[0037] (3) Application: After the crops are transplanted or sown, dilute the microbial agent with water in a weight ratio of 1:1000 in clean water to make a diluted solution. Then use a spray pot or a ladle to apply it. The specific method is to spray or irrigate the diluted solution directly on the soil in the planting area, and try to ensure uniform irrigation. The usage of microbial agents for preventing root-knot nematode disease and clubroot disease is 2 to 5 kg per mu.

[0038] (4) Hole application: When crops are transplanted, place the fungicide directly into the hole for transplanting. Use 1 to 3 grams per crop. The specific method is to put the fungicide powder directly into the hole for transplanting, mix it with the bottom soil, and then transplant the crops. Water as soon as possible after transplanting and covering the soil to promote the rapid germination of spores and spores in the fungicide in a humid environment to form biological control.

[0039] Furthermore: the above four methods of use can be used in combination according to actual conditions, such as root dipping and watering can be used in combination throughout the entire growth period; hole application and root irrigation can be used in combination; hole application, root irrigation and watering can be used in combination; and other combinations not mentioned.

[0040] Example 2

[0041] This embodiment provides a microbial agent for preventing both root-knot nematode disease and clubroot disease, and a method for using the microbial agent in combination with a matrix to prepare a functional seedling culture matrix.

[0042] The microbial agent for preventing root-knot nematode disease and root-swelling disease of the present invention is prepared by compounding the powders of three strains: methylotrophic Bacillus WSWFJ-29 (with a deposit registration number of CGMCC No. 18269), Paecilomyces lilacinus WSWFJ-28 (with a deposit registration number of CGMCC No. 18274), and Bacillus subtilis WSWFJ44 (with a deposit registration number of CGMCC No. 20144). The effective viable count of methylotrophic Bacillus and Bacillus subtilis is not less than 1×10 11 CFU / g of Bacillus microbial powder, and the spore quantity of Paecilomyces lilacinus reached 1×10 10 CFU / g of Paecilomyces lilacinus spore powder. Methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are physically mixed in the proportion of 8 parts by weight: 1 part: 2 parts by weight, and after mixing, a microbial agent for preventing root-knot nematode disease and clubroot disease is obtained.

[0043] Furthermore: the three kinds of bacterial powder are packaged separately, mixed when in use, and used within 48 hours after mixing to avoid the reduction of the number of effective live bacteria due to the mutual influence between the bacterial strains caused by too long mixing time.

[0044] The microbial agent for preventing both root-knot nematode disease and clubroot disease of the present invention can be combined with a matrix to prepare a functional seedling matrix for use, and disease prevention and control can be performed during the seedling stage, which can effectively reduce the outbreak of diseases after crop transplanting. The specific method of use is as follows:

[0045] The microbial agent and the seedling substrate are mixed in a weight ratio of 1 to 5:1000, and after being mixed evenly, they are used for seedling cultivation of crops, and the seedling cultivation can be carried out according to the conventional seedling cultivation method. The crop seedlings obtained by this method have disease-resistant bacteria in the root substrate soil and the plants when transplanted, and can effectively prevent and control root-knot nematode disease and clubroot disease after transplanting. After transplanting, the microbial agent can be used for root irrigation or watering 1 to 2 times, which can improve the prevention and control effect by more than 10%.

[0046] Example 3

[0047] This embodiment provides a microbial agent for preventing both root-knot nematode disease and clubroot disease and a method for using the microbial agent in combination with an organic fertilizer to prepare a functional biological organic fertilizer.

[0048] The microbial agent for preventing root-knot nematode disease and root-swelling disease of the present invention is prepared by compounding the powders of three strains: methylotrophic Bacillus WSWFJ-29 (with a deposit registration number of CGMCC No. 18269), Paecilomyces lilacinus WSWFJ-28 (with a deposit registration number of CGMCC No. 18274), and Bacillus subtilis WSWFJ44 (with a deposit registration number of CGMCC No. 20144). The effective viable count of methylotrophic Bacillus and Bacillus subtilis is not less than 1×10 11 CFU / g of Bacillus microbial powder, and the spore quantity of Paecilomyces lilacinus reached 1×10 10 CFU / g of Paecilomyces lilacinus spore powder. Methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder are physically mixed in the proportions of 5 parts, 1 part and 4 parts by weight respectively, and after mixing, a microbial agent for preventing root-knot nematode disease and clubroot disease is obtained.

[0049] Furthermore: the three kinds of bacterial powder are packaged separately, mixed when in use, and used within 48 hours after mixing to avoid the reduction of the number of effective live bacteria due to the mutual influence between the bacterial strains caused by too long mixing time.

[0050] The microbial agent for preventing both root-knot nematode disease and clubroot disease of the present invention can be mixed with organic fertilizer to make functional biological organic fertilizer for use, enter the soil when applying base fertilizer, and prevent and control diseases during the crop transplanting stage, which can effectively reduce the outbreak of diseases after crop transplanting. The specific use method is as follows:

[0051] Mix the microbial agent and organic fertilizer in a weight ratio of 4 to 7:1000, mix evenly and use as base fertilizer when transplanting crops. The specific method is:

[0052] According to the fertilizer requirement characteristics of crops, the bio-organic fertilizer in the present embodiment is used as basal fertilizer when crops are transplanted, and the application amount is 50-200kg / mu. Conventional basal fertilizer application methods such as hole application, strip application, and furrow application can be adopted. After application, timely transplanting and watering are carried out to promote the rapid germination of spores and spores in the bio-organic fertilizer in a humid environment to form biological control. Other measures can be carried out according to conventional farming operations. Crop planting is carried out according to this method, and colonization of disease-resistant bacteria can be formed in the soil around the root system during transplanting, and effective control can be formed for root-knot nematode disease and clubroot disease after transplanting. After transplanting, microbial agents can be used to irrigate the roots or pour them for 1-2 times, which can improve the control effect by more than 10%. If the transplanted crop seedlings are cultivated by the seedling culture medium in Example 2, the whole process of disease control can be formed for crops, which can improve the control effect by more than 50%.

[0053] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A microbial agent for preventing both root-knot nematode disease and clubroot disease, characterized in that: The invention comprises the following strains: methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis, and the microbial agent is a composite agent prepared by compounding the bacterial powders of methylotrophic Bacillus, Paecilomyces lilacinus and Bacillus subtilis; wherein, The methylotrophic Bacillus (Bacillus methylotrophicus) is numbered WSWFJ 29 and its deposit registration number is CGMCC No.18269; The Paecilomyces lilacinus is numbered WSWFJ 28 and its deposit registration number is CGMCC No. 18274; The Bacillus subtilis is numbered WSWFJ44 and its deposit registration number is CGMCC No.20144.

2. The microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 1, characterized in that: The effective viable count of methylotrophic Bacillus and Bacillus subtilis is not less than 1×10 11 CFU / g of Bacillus microbial powder; the spore quantity of Paecilomyces lilacinus reached 1×10 10 CFU / g of Paecilomyces lilacinus spore powder.

3. The microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 2, characterized in that: The methylotrophic Bacillus powder, the spore powder of Paecilomyces lilacinus and the Bacillus subtilis powder are compounded according to the following weight proportions: 3-8 parts of the methylotrophic Bacillus powder, 1 part of the spore powder of Paecilomyces lilacinus and 2-5 parts of the Bacillus subtilis powder.

4. The microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 3, characterized in that: The methylotrophic Bacillus powder, the Paecilomyces lilacinus spore powder and the Bacillus subtilis powder are compounded according to the following weight portions: 3 parts of the methylotrophic Bacillus powder, 1 part of the Paecilomyces lilacinus spore powder and 5 parts of the Bacillus subtilis powder.

5. The microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 3, characterized in that: The methylotrophic Bacillus powder, the Paecilomyces lilacinus spore powder and the Bacillus subtilis powder are compounded according to the following weight portions: 8 parts of the methylotrophic Bacillus powder, 1 part of the Paecilomyces lilacinus spore powder and 2 parts of the Bacillus subtilis powder.

6. The microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 3, characterized in that: The methylotrophic Bacillus powder, the spore powder of Paecilomyces lilacinus and the Bacillus subtilis powder are compounded according to the following weight portions: 5 parts of the methylotrophic Bacillus powder, 1 part of the spore powder of Paecilomyces lilacinus and 4 parts of the Bacillus subtilis powder.

7. Use of the microbial agent for preventing both root-knot nematode disease and clubroot disease according to any one of claims 1 to 6 in the cultivation of cruciferous plants.

8. Use of the microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 7 in the planting of cruciferous plants, characterized in that: The methylotrophic Bacillus powder, the Paecilomyces lilacinus spore powder and the Bacillus subtilis powder are packaged and stored separately and mixed when used.

9. Use of the microbial agent for preventing both root-knot nematode disease and clubroot disease according to claim 8 in the planting of cruciferous plants, characterized in that: After mixing methylotrophic Bacillus powder, Paecilomyces lilacinus spore powder and Bacillus subtilis powder, use within 48 hours.

10. Use of the microbial agent for preventing both root-knot nematode disease and clubroot disease according to any one of claims 7 to 9 in the cultivation of cruciferous plants, characterized in that: The microbial agent is applied to crops by one or more methods of root dipping, root irrigation, pouring and hole application; or the microbial agent is combined with a matrix and a fertilizer to prepare a functional seedling matrix and a biological fertilizer for use.