Microbial agent for preventing and treating root rot and application thereof

Abstract

The invention relates to a microbial agent for preventing and treating root rot and application of the microbial agent. A strain in the microbial agent comprises a combination of bacillus mucilaginosus and amycolatopsis. The bacillus mucilaginosus and the amycolatopsis are compounded and combined to find that the bacillus mucilaginosus and the amycolatopsis are matched with each other and have a synergistic effect, so that related pathogenic bacteria of root rot can be more effectively inhibited, the abundance of beneficial bacteria in soil is improved, the plant resistance is improved, and a good improvement effect on the air permeability of the soil is also achieved. Therefore, the microbial agent has a good prospect in prevention and treatment of the root rot and control of occurrence and development of the root rot, and is of great significance to fruit production of related plants and food safety.

Description

Technical Field

[0001] The invention relates to the field of plant disease prevention and treatment, and in particular to a microbial agent for preventing and treating root rot and an application thereof. Background Art

[0002] Kiwifruit is a fruit tree belonging to the genus Actinidia, a vine of the family Actinidiaceae. It is rich in nutritional and medicinal properties. It contains high levels of dietary fiber, sugar, vitamin C and vitamin E, minerals, omega-3 fatty acids and antioxidants. The nutritional content of kiwifruit ranks among the top of other fruits, and it is known as the king of vitamin C among fruits. It can not only be eaten directly, but also processed into kiwifruit juice, fruit wine, preserved fruit, jam, dried fruit, fruit cake and other delicious foods, which are deeply loved by people.

[0003] Kiwi root rot is a fungal disease that mainly harms the root system of kiwi fruit, causing phloem corruption, which hinders the absorption and transportation of nutrients and minerals by the root system of kiwi fruit, resulting in poor growth of the aboveground part of kiwi fruit, and even death of the plant. There are many reasons for kiwi root rot: First, the texture of the orchard soil is heavy and dry, with poor air permeability, which leads to poor root growth and causes root rot. Second, the orchard soil lacks organic matter, which is not conducive to the development of kiwi root system, thus causing root rot. Third, the groundwater level in the orchard is high, and water accumulation is serious during the rainy season, which causes root rot. Fourth, the pH value of the orchard is too high, the iron element is fixed, and the fruit trees cannot absorb it normally, resulting in iron deficiency, which causes root rot. Fifth, when fruit farmers are working, the roots are injured and the fruit trees are too weak due to excessive fruit hanging, which causes root rot. Planting too deep will hinder the respiration of the root system, which is easy to cause root rot. Sixth, the trees have too many fruits or have been treated with Daguoling for many years, which weakens the trees and reduces their resistance, making root rot more likely to occur. Seventh, the seedlings are infected with bacteria, and the plants are susceptible to the disease after planting, and they are not treated in time, which leads to root rot.

[0004] At present, the prevention and control of kiwifruit root rot mainly adopts chemical agent irrigation. However, the long-term and large-scale use of chemical agents not only pollutes the environment and causes excessive pesticide residues, but also reduces the types and number of soil microorganisms, soil compaction, and a vicious cycle of the entire orchard ecological environment, resulting in a sharp decrease in kiwifruit yield and quality. Introducing microbial agents to improve soil permeability and inhibit pathogens to control the occurrence of kiwifruit root rot has become an important research direction. Therefore, how to provide a microbial agent product that can effectively prevent kiwifruit root rot and related prevention and control methods has become an urgent problem to be solved. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a microbial agent for preventing and treating root rot and its application.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a microbial agent for preventing and treating root rot, wherein the strains in the microbial agent include a combination of Bacillus subtilis and Amycolatopsis spp.

[0008] In the present invention, it is creatively found that the combination of Bacillus subtilis and Amycolatopsis spp. for the prevention and treatment of root rot has a more significant and excellent effect than a single bacterial agent or other combination methods, indicating that Bacillus subtilis and Amycolatopsis spp. have a synergistic effect in improving soil permeability and inhibiting root rot-related pathogens.

[0009] Preferably, the strains in the microbial inoculant include a combination of Bacillus mucilaginosus ACCC 02983 and Amycolatopsis spp. JCM15899.

[0010] Preferably, the ratio of the viable counts of Bacillus subtilis and Amycolatopsis spp. is (1-10):(1-10);

[0011] Here, “1-10” can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Other specific point values ​​within the numerical range can be selected, and they will not be described one by one here.

[0012] Preferably, the dosage form of the microbial agent includes liquid, powder, tablet or granule.

[0013] The preparation method of the microbial agent can be prepared by conventional technical methods in the art, and exemplarily, it can be: inoculating an activated Bacillus subtilis strain into a culture medium and culturing it at 25-30° C. for 18-22 hours to obtain a Bacillus subtilis bacterial solution; inoculating an activated Amycolatopsis pseudomycoticus strain into a culture medium and culturing it at 35-38° C. for 18-22 hours to obtain a Amycolatopsis pseudomycoticus bacterial solution, and mixing the two bacterial solutions according to the ratio of live bacteria counts, or further adding a protective agent for freeze-drying to obtain a freeze-dried bacterial powder product;

[0014] The above-mentioned "25-30°C" may be, for example, 25°C, 25.5°C, 26°C, 26.5°C, 27°C, 27.5°C, 28°C, 28.5°C, 29°C, 29.5°C, 30°C, etc.;

[0015] The above-mentioned “18-22h” may be, for example, 1h, 18.5h, 19h, 19.5h, 20h, 20.5h, 21h, 21.5h, 22h, etc.;

[0016] The above-mentioned "35-38°C" can be, for example, 35°C, 35.5°C, 36°C, 36.5°C, 37°C, 37.5°C, 38°C, etc. Other specific point values ​​within the numerical range can be selected, and they will not be described one by one here.

[0017] In a second aspect, the present invention provides a use of the microbial agent as described in the first aspect in preventing and controlling plant root rot.

[0018] In a third aspect, the present invention provides a method for preventing and controlling kiwifruit root rot, comprising applying the microbial agent described in the first aspect to kiwifruit plants.

[0019] Preferably, when the microbial agent is a liquid agent, the application concentration is OD 600 =0.4-0.6, for example, it can be 0.4, 0.42, 0.45, 0.48, 0.5, 0.51, 0.52, 0.55, 0.26, 0.58, 0.6, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0020] Preferably, the control method specifically comprises the following steps:

[0021] (1) Apply earthworm fertilizer on the 7th to 15th day after the kiwifruit plants enter the leaf-falling period, where "7-15" can be, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, etc.;

[0022] (2) Applying fermented yellow water on the 15th to 30th day after the plant ends its dormancy period, wherein “15-30” can be, for example, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, etc.;

[0023] (3) Apply the microbial agent described in the first aspect on the 1st to 10th day after the plant enters the budding stage, wherein "1-10" can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc. Other specific point values ​​within this numerical range can be selected and will not be described in detail here.

[0024] In the present invention, the application of earthworm fertilizer can effectively improve soil compaction and increase soil nutrient content; fermented yellow water contains rich organic matter and various trace elements such as nitrogen, phosphorus, potassium, etc., and is a very high-quality natural fertilizer. After the yellow water is added, it can not only provide nutrients for the plants, but also provide nutrients for the growth of the microbial strains introduced subsequently. At the same time, the organic acid contained in the yellow water can cause metabolic disorders of harmful bacteria, and even lysis, which can effectively inhibit harmful bacteria. When used in combination with microbial agents, it effectively improves the prevention and control effect of kiwi root rot and improves the fruit quality and yield.

[0025] Preferably, the earthworm fertilizer is applied by trenching and fertilizing followed by soil covering and landfilling, and the application amount is 1.8-2.5t / mu, for example, it can be 1.8t / mu, 1.9t / mu, 2t / mu, 2.1t / mu, 2.2t / mu, 2.3t / mu, 2.4t / mu, 2.5t / mu, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0026] Preferably, the method for preparing the fermented yellow water is to aerobically ferment the yellow water at 23-28° C. for 7-10 days and then mix the yellow water with water in a volume ratio of 1:(7-14) to obtain the fermented yellow water;

[0027] The above-mentioned "23-28°C" may be, for example, 23°C, 23.5°C, 24°C, 24.5°C, 25°C, 25.5°C, 26°C, 26.5°C, 27°C, 27.5°C, 28°C, etc.;

[0028] The above-mentioned “7-10 days” may be, for example, 7 days, 7.5 days, 8 days, 8.5 days, 9 days, 9.5 days, 10 days, etc.;

[0029] The above-mentioned "1:(7-14)" can be, for example, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0030] Preferably, the fermented yellow water is applied by spraying on the soil surface, and the application amount is 1.8-2.5t / mu, for example, it can be 1.8t / mu, 1.9t / mu, 2t / mu, 2.1t / mu, 2.2t / mu, 2.3t / mu, 2.4t / mu, 2.5t / mu, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0031] Preferably, the microbial agent is applied by trenching and fertilizing followed by soil covering and landfilling, and the application amount is 0.5-1t / mu, for example, it can be 0.5t / mu, 0.55t / mu, 0.6t / mu, 0.65t / mu, 0.7t / mu, 0.75t / mu, 0.8t / mu, 0.85t / mu, 0.9t / mu, 0.95t / mu, 1t / mu, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0032] The present invention uses a specific amount of microbial agent to further improve the prevention and control effect of root rot.

[0033] Preferably, in step (1), decomposed organic fertilizer is also applied to the kiwifruit plants 15-25 days before the leaf fall period, wherein "15-25" can be, for example, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, etc. Other specific point values ​​within this numerical range can be selected and will not be described one by one here.

[0034] Preferably, the application method of the decomposed organic fertilizer is trenching and fertilizing followed by covering and landfilling, and the application amount is 1.8-3.2t / mu, for example, it can be 1.8t / mu, 1.9t / mu, 2t / mu, 2.1t / mu, 2.2t / mu, 2.3t / mu, 2.4t / mu, 2.5t / mu, 2.6t / mu, 2.7t / mu, 2.8t / mu, 2.9t / mu, 3t / mu, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0035] Preferably, nitrogen fertilizer is applied on the 15th to 30th day after the plants end their dormancy period in step (2), wherein "15-30" can be, for example, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, etc., and the application amount is 5-12kg, for example, 5kg / mu, 6kg / mu, 7kg / mu, 8kg / mu, 9kg / mu, 10kg / mu, 11kg / mu, 12kg / mu, etc. Other specific point values ​​within this numerical range can be selected and will not be described one by one here.

[0036] Preferably, a fungicide is also applied before applying the earthworm manure in step (1).

[0037] Preferably, the fungicide comprises cymoxanil mancozeb.

[0038] Cymoxanil mancozeb fungicide is a binary fungicide mixed with cymoxanil and fully complexed mancozeb. It is low-toxic, low-residue, and has both protective and therapeutic effects. Cymoxanil has a strong systemic effect, which can not only prevent the germination of pathogenic spores, but also has a good killing effect on pathogens that invade plant tissues. After application, it can further enhance the prevention and control and killing effects of root rot-related pathogens.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The present invention creatively develops a new microbial compounding method and a new kiwifruit root rot prevention and control strategy, that is, the combination of Bacillus subtilis and Amycolatopsis spp. is compounded and used. It is found that the two components cooperate with each other and synergistically enhance the effect, which can more effectively inhibit the pathogens related to root rot and also have a good improvement effect on soil permeability. Therefore, the use of the microbial agent in the prevention and control of root rot has a good prospect. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0042] The earthworm fertilizer involved in the following embodiments is a product purchased from Chengdu Huahong Biotechnology Co., Ltd.; the yellow water is purchased from Shuzhiyuan Wine Company; the decomposed organic fertilizer is a product of the model "Zhubang" organic matter decomposition agent (liquid) purchased from Chengdu Huahong Biotechnology Co., Ltd.; the compound fertilizer (phosphate fertilizer + potash fertilizer) is a product of the model "Zhubang" flash expanded potassium dihydrogen phosphate purchased from Chengdu Huahong Biotechnology Co., Ltd.;

[0043] The strains involved in the following examples are Bacillus subtilis ACCC 02983; Bacillus subtilis ACCC19759;

[0044] Amycolatopsis JCM 15899; Amycolatopsis CCTCC AB 2013252; Amycolatopsis CCTCC AB2014129;

[0045] Bacillus subtilis CCTCC AB 130168; Bacillus laterosporus CTCC CB 20082249.

[0046] The pathogens involved in the following examples: Fusarium solani and Fusarium oxysporum, were isolated, identified and preserved from the diseased root parts of kiwifruit.

[0047] The culture medium of the Bacillus subtilis in the following preparation example is (mass percentage): sucrose 1%, yeast extract 0.02%, (NH 4 ) 2 SO 4 0.05%, MgSO 4 0.01%、KCL 0.01%、Na 2 HPO 4 0.01% and CaCO 3 0.1%;

[0048] The culture medium for Amycolatopsis was ISP2 medium supplemented with 5% NaCl;

[0049] The kiwifruit involved in the following application examples are all ten-year-old kiwifruit plants in the peak fruit-bearing period.

[0050] Preparation Example 1

[0051] This preparation example provides two types of Bacillus subtilis suspensions. The preparation method comprises the following steps: inoculating the strain into a liquid culture medium, culturing at 37° C. for 18 h for activation, and continuously activating the suspension twice to obtain an activated solution; inoculating the activated solution into a new liquid culture medium at an inoculation rate of 10% (v / v), culturing at 28° C. for 48 h to obtain a bacterial solution; centrifuging the bacterial solution at 5000 rpm for 10 min, filtering the suspension to obtain bacterial cells, and resuspending the bacterial cells in a PBS solution to obtain the obtained suspension.

[0052] Preparation Example 2

[0053] This preparation example provides three types of Amycolatopsis pseudomycoticus suspensions. The preparation method comprises the following steps: inoculating the strain into a liquid culture medium, culturing at 37° C. for 18 h for activation, and continuously activating twice to obtain an activated solution; inoculating the activated solution into a new liquid culture medium at an inoculum amount of 10% (v / v), culturing at 37° C. for 24 h to obtain a bacterial solution; centrifuging the bacterial solution at 8000 rpm for 10 min, filtering to obtain bacterial bodies, and resuspending the bacterial bodies in a PBS solution to obtain the obtained product.

[0054] Preparation Example 3

[0055] The present preparation example provides a Bacillus subtilis suspension, and the preparation method comprises the following steps: inoculating the strains into skim milk respectively, culturing at 37° C. for 18 h for activation, and obtaining an activated solution; inoculating the activated solution into an MRS culture medium at an inoculum amount of 4% (v / v), culturing at 37° C. for 20 h, and obtaining a bacterial solution; centrifuging the bacterial solution at 8000 g for 10 min, filtering, obtaining bacterial bodies, and resuspending the bacterial bodies in a PBS solution.

[0056] Preparation Example 4

[0057] The present preparation example provides a Bacillus laterosporus bacterial suspension, and the preparation method comprises the following steps: inoculating the strains into skim milk respectively, culturing at 37° C. for 18 h for activation, and obtaining an activated solution; inoculating the activated solution into an MRS culture medium at an inoculum amount of 4% (v / v), culturing at 37° C. for 20 h, and obtaining a bacterial solution; centrifuging the bacterial solution at 8000 g for 10 min, filtering, and obtaining bacterial bodies, and resuspending the bacterial bodies in a PBS solution.

[0058] Example 1

[0059] This embodiment provides a microbial inoculant, which is composed of a bacterial suspension of Bacillus subtilis ACCC 02983 and a bacterial suspension of Amycolatopsis simulans JCM 15899 at a live cell count ratio of 1:1.

[0060] Example 2

[0061] This embodiment provides a microbial inoculant, which is composed of a bacterial suspension of Bacillus subtilis ACCC 19759 and a bacterial suspension of Amycolatopsis CCTCC AB 2013252 with a live cell count ratio of 8:3.

[0062] Example 3

[0063] This embodiment provides a microbial inoculant, which is composed of a bacterial suspension of Bacillus subtilis ACCC 02983 and a bacterial suspension of Amycolatopsis CCTCC AB 2014129 with a live cell count ratio of 2:7.

[0064] Comparative Example 1

[0065] This comparative example provides a microbial agent, which is a bacterial suspension of Bacillus subtilis ACCC 02983.

[0066] Comparative Example 2

[0067] This comparative example provides a microbial agent, which is a suspension of Amycolatopsis spp. JCM 15899.

[0068] Comparative Example 3

[0069] This comparative example provides a microbial agent, which is composed of a bacterial suspension of Bacillus subtilis CCTCC AB130168 and a bacterial suspension of Amycolatopsis spp. JCM 15899 at a live bacterial count ratio of 1:1.

[0070] Comparative Example 4

[0071] This comparative example provides a microbial agent, which is composed of a bacterial suspension of Bacillus laterosporus CTCC CB20082249 and a bacterial suspension of Amycolatopsis simulans JCM 15899 at a live cell count ratio of 1:1.

[0072] Test Example 1

[0073] Experiment on the control of kiwifruit root rot with chemicals in potted plants

[0074] (1) Preparation of pathogenic bacteria mixed suspension: The isolated, identified and preserved Fusarium solani and Fusarium oxysporum strains were inoculated into PDA medium by the plate streak method and cultured at 25°C in the dark for 5 days. When the colonies grew to 2 / 3 of the culture dish, an appropriate amount of mycelium was inoculated into 150 mL of PDB medium and cultured at 25°C with shaking at 200 rpm for 5 days. The obtained culture was then centrifuged at 8000 rpm for 5 min to obtain the bacterial cells. The spore content was diluted to a concentration of 1×10 6 / mL, and the two bacterial suspensions of Fusarium solani and Fusarium oxysporum were mixed in a ratio of 1:1 to obtain a mixed pathogenic bacteria suspension.

[0075] (2) The pot test was conducted at 25°C. A sterile scalpel was used to scratch the root junction of a healthy one-year-old kiwifruit plant for about 1 cm, and the wound was irrigated with the prepared mixed pathogenic bacteria suspension. Each plant was irrigated with 10 mL of the bacterial suspension, and an equal amount of sterile water was used as a control. Each treatment was repeated 5 times. The microbial agents prepared in Examples 1-3 and Comparative Examples 1-2 were diluted to OD 600 The concentration of 0.4, 0.5 and 0.6 was used. At the early stage of kiwifruit root rot, 50 mL of water was used for each root irrigated, and the blank control group was treated with sterile water. During the test, the pesticide was applied 4 times, with an interval of 2 days between each application. The disease condition of the plants was observed 5 days after the last irrigation, and the incidence rate was calculated. The disease index was calculated according to the disease grading standard, and the relative prevention effect of the microbial agent was calculated according to the following formula. The results are shown in Table 1.

[0076]

[0077] Among them, the disease grading standards are: Level 0: the main root of the plant grows normally, and there is no disease in the rhizome; Level 1: slight symptoms appear in the root neck, but the internal tissue is not infected; Level 3: the rhizome shows obvious symptoms, and dark brown water-soaked spots appear; Level 5: white hyphae appear, the roots and wood begin to rot, and there is a smell of wine lees; Level 7: the rotten part of the roots accounts for more than 30% of the total roots, forming light yellow rapeseed-sized pathogenic bacteria sclerotia; Level 9: The roots all turn black and rot, the above-ground leaves turn yellow and fall off, and wilt and die.

[0078] Table 1

[0079]

[0080]

[0081] The data in the table show that both the suspensions of Bacillus mucilaginosus and Amycolatopsis can prevent and control the occurrence of kiwifruit root rot and reduce the incidence of the disease, and Bacillus mucilaginosus has the best control effect, which can significantly reduce the incidence of kiwifruit root rot. In addition, it was unexpectedly found that the combined use of Bacillus mucilaginosus and Amycolatopsis has a better control effect on kiwifruit root rot.

[0082] Application Example 1

[0083] This application example provides a method for preventing and controlling kiwifruit root rot, which comprises the following steps:

[0084] (1) After the first round of fruit picking in late October, dig a 35 cm deep and 30 cm wide ring ditch around the tree circle, apply decomposed organic fertilizer at a rate of 2.5 t / mu, and irrigate and cover with soil;

[0085] (2) In early November, dig a 10 cm deep annular trench within a radius of 30 cm around the plant, scrape off the old skin and lesions at the root neck with a knife, and apply 72% cymoxanil mancozeb wettable powder to the soil within 1 m from the plant at a rate of 120 g / mu. Apply the same amount of cymoxanil mancozeb wettable powder again after 10 days.

[0086] (3) In late November, dig a 20 cm deep and 30 cm wide ring ditch 1 m away from the plant, apply earthworm fertilizer at a rate of 2.5 t / mu, and cover with soil;

[0087] (4) In late February of the following year, 8 kg / mu of urea was applied in combination with irrigation; yellow water fermented at 25°C for 8 days was diluted in a ratio of 1:9 and sprayed on the soil surface, with an application rate of 2 t / mu;

[0088] (5) In early April, the microbial agent prepared in Example 1 was diluted to an OD of 600 When the temperature is 0.5, a 15cm deep and 30cm wide annular ditch is opened 1m away from the plant, and microbial agents are applied. The soil and bacterial solution are mixed and then refilled into the ditch. The application rate of bacterial solution is 0.8t / mu.

[0089] (6) In late May, one week after the plants have finished flowering, apply 120 g of compound fertilizer (phosphate fertilizer + potash fertilizer) per plant;

[0090] (7) In late July, when the fruit is in its later stages of growth, apply 300 g of compound fertilizer (phosphate fertilizer + potassium fertilizer) to each plant.

[0091] Application Example 2

[0092] This application example provides a method for preventing and controlling kiwifruit root rot, which comprises the following steps:

[0093] (1) After the first round of fruit picking in late October, dig a 35 cm deep and 30 cm wide ring ditch around the tree circle, apply decomposed organic fertilizer at a rate of 2 t / mu, irrigate and cover with soil;

[0094] (2) In early November, dig a 10 cm deep annular trench within a radius of 30 cm around the plant, scrape off the old skin and lesions at the root neck with a knife, and apply 72% cymoxanil mancozeb wettable powder to the soil within 1 m from the plant at a rate of 110 g / mu. Apply the same amount of cymoxanil mancozeb wettable powder again after 10 days.

[0095] (3) In late November, dig a 20 cm deep and 30 cm wide ring ditch 1 m away from the plant, apply earthworm fertilizer at a rate of 2 t / mu, and cover with soil;

[0096] (4) In late February of the following year, 10 kg / mu of urea was applied in combination with irrigation; yellow water fermented at 28°C for 7 days was diluted in a ratio of 1:13 and sprayed on the soil surface, with an application rate of 1.8 t / mu;

[0097] (5) In early April, the microbial agent prepared in Example 2 was diluted to an OD of 600 When the humidity is 0.5, a 15cm deep and 30cm wide annular ditch is opened 1m away from the plant, and microbial agents are applied. The soil and bacterial solution are mixed and then refilled into the ditch. The amount of bacterial solution applied is 0.7t / mu. ;

[0098] (6) In late May, one week after the plants have finished flowering, apply 150 g of compound fertilizer (phosphate fertilizer + potash fertilizer) per plant;

[0099] (7) In late July, when the fruit is in its later stages of growth, apply 260 g of compound fertilizer (phosphate fertilizer + potassium fertilizer) to each plant.

[0100] Application Example 3

[0101] This application example provides a method for preventing and controlling kiwifruit root rot, which comprises the following steps:

[0102] (1) After the first round of fruit picking in late October, dig a 35 cm deep and 30 cm wide ring ditch around the tree circle, apply decomposed organic fertilizer at a rate of 2.8 t / mu, and irrigate and cover with soil;

[0103] (2) In early November, dig a 10 cm deep annular trench within a radius of 30 cm around the plant, scrape off the old skin and lesions at the root neck with a knife, and apply 72% cymoxanil mancozeb wettable powder to the soil within 1 m from the plant at a rate of 100 g / mu. Apply the same amount of cymoxanil mancozeb wettable powder again after 10 days.

[0104] (3) In late November, dig a 20 cm deep and 30 cm wide ring ditch 1 m away from the plant, apply earthworm fertilizer at a rate of 3 t / mu, and cover with soil;

[0105] (4) In late February of the following year, urea was applied at 6 kg / mu in combination with irrigation; yellow water fermented at 23°C for 10 days was diluted at a ratio of 1:8 and sprayed on the soil surface, with an application rate of 2.4 t / mu;

[0106] (5) In early April, the microbial agent prepared in Example 3 was diluted to an OD of 600 When the soil temperature reaches 0.5, a 15cm deep and 30cm wide annular ditch is opened 1m away from the plant, and microbial agents are applied. After the soil and bacterial solution are mixed, the soil is refilled into the ditch. The amount of bacterial solution applied is 0.6t / mu.

[0107] (6) In late May, one week after the plants have finished flowering, apply 100 g of compound fertilizer (phosphate fertilizer + potash fertilizer) per plant;

[0108] (7) In late July, when the fruit is in its later stages of growth, apply 280 g of compound fertilizer (phosphate fertilizer + potassium fertilizer) to each plant.

[0109] Application Example 4

[0110] This application example provides a method for controlling kiwifruit root rot, which is different from that of application example 1 only in step (2), in that mancozeb wettable powder is not applied, and then subsequent treatments are carried out in sequence.

[0111] Application Example 5

[0112] This application example provides a method for controlling kiwifruit root rot. The control method is different from that of application example 1 only in that the treatment of applying earthworm manure in step (3) is not performed, and subsequent treatments are performed in sequence.

[0113] Application Example 6

[0114] This application example provides a method for preventing and controlling kiwifruit root rot. The only difference between the prevention and control method and the application example 1 is step (4). The difference is that after applying urea, fermented yellow water is not applied, and then subsequent treatments are carried out in sequence.

[0115] Comparative application example 1

[0116] This comparative application example provides a method for preventing and controlling kiwifruit root rot. The only difference between the method and application example 1 is step (5). The difference is that the microbial agent used is the microbial agent prepared in comparative example 1.

[0117] Comparative Application Example 2

[0118] This comparative application example provides a method for preventing and controlling kiwifruit root rot. The only difference between the method and application example 1 is step (5). The difference is that the microbial agent used is the microbial agent prepared in comparative example 2.

[0119] Comparative Application Example 3

[0120] This comparative application example provides a method for preventing and controlling kiwifruit root rot. The only difference between the method and application example 1 is step (5). The difference is that the microbial agent used is the microbial agent prepared in comparative example 3.

[0121] Comparative Application Example 4

[0122] This comparative application example provides a method for preventing and controlling kiwifruit root rot. The only difference between the method and application example 1 is step (5). The difference is that the microbial agent used is the microbial agent prepared in comparative example 4.

[0123] Comparative Application Example 5

[0124] This comparative application example provides a method for controlling kiwifruit root rot, which is different from the control method in application example 1 only in that the treatment of applying a microbial agent in step (5) is not performed, and subsequent treatments are then performed in sequence.

[0125] Test Example 2

[0126] This test example tests the kiwifruit yield, soil porosity, and the abundance of beneficial and harmful bacteria in the soil under the control methods provided in Example 1-6 and Comparative Application Example 1-5. At the same time, kiwifruit plants under the original planting conditions are selected as the control group (without any external nutrient addition, including fertilizer, yellow water, and microbial agents, etc.).

[0127] The soil porosity is tested by the ring knife method; the bacterial abundance is tested by the high-throughput sequencing method.

[0128] Fusarium can cause root rot in kiwifruit growing areas. It causes the tree to wilt, the vascular tissue of the roots and stems to turn brown and necrotize, the plant growth declines, the upper branches and leaves lose water and dry up and fall off, and even the entire plant dries up and dies. Cladosporium can cause black spot disease in kiwifruit. It can cause leaf spots, scabs, post-harvest rot and other disease symptoms, resulting in reduced production. Cylindrospermum is the main pathogenic microorganism that causes kiwifruit root rot. Fecal sphaeroides can cause fruit tree rot, brown spot, sooty mold, etc.

[0129] The above test results are shown in Table 2.

[0130] Table 2

[0131]

[0132]

[0133]

[0134] From the data in the table, we can see that:

[0135] (1) It can be seen from Application Examples 1 to 3 that the microbial agent provided by the present invention can improve soil permeability, inhibit root rot-related pathogens, increase the abundance of beneficial bacteria in the soil, thereby improving plant resistance, promoting plant absorption of nutrients, and effectively increasing yield.

[0136] (2) By comparing Application Example 1 with Application Example 4, it can be seen that when the wettable powder of mancozeb is not applied in the control method of Application Example 4, the control effect and yield improvement effect are not as good as those of Application Example 1, indicating that the addition of a fungicide in the present invention can further improve the control effect of root rot.

[0137] (3) By comparing Application Example 1 with Application Example 5, it can be seen that when earthworm manure is not applied in the control method of Application Example 5, its technical effect is worse than that of Application Example 1. Since earthworm manure can increase soil porosity, increase air permeability, and promote root respiration, it shows that adding earthworm manure in the present invention can further enhance the control effect of root rot.

[0138] (4) By comparing Application Example 1 with Application Example 6, it can be seen that when fermented yellow water is not applied in the control method of Application Example 6, the control effect of root rot is reduced compared with Application Example 1. This indicates that the addition of yellow water in the present invention can further improve the control effect of root rot.

[0139] (5) By comparing Application Example 1 with Comparative Application Examples 1-5, it can be seen that after adding microbial agents in the present invention, the control effect of kiwifruit root rot can be effectively improved and the yield can be increased. Moreover, when Bacillus subtilis and Amycolatopsis pseudomycoticus are used in combination, the control effect of kiwifruit root rot is better.

[0140] In summary, the present invention creatively develops a new microbial compounding method and a new kiwifruit root rot prevention and control strategy, that is, the combination of Bacillus subtilis and Amycolatopsis spp. is compounded and used, and it is found that the two components cooperate with each other to synergistically enhance the effect, which can more effectively inhibit the pathogens related to root rot, and also has a good improvement effect on the soil permeability. Therefore, the use of the microbial agent in the prevention and control of root rot has a good prospect.

[0141] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0142] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0143] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A microbial agent for preventing and treating root rot, characterized in that: The strains in the microbial inoculant include a combination of Bacillus subtilis and Amycolatopsis spp.

2. The microbial agent according to claim 1, characterized in that The ratio of the viable counts of the Bacillus subtilis and Amycolatopsis spp. is (1-10):(1-10); Preferably, the dosage form of the microbial agent includes liquid, powder, tablet or granule.

3. Use of the microbial agent as claimed in claim 1 or 2 in preventing and treating plant root rot.

4. A method for preventing and treating kiwifruit root rot, characterized in that: The control method comprises applying the microbial agent as claimed in claim 1 or 2 to kiwi fruit plants.

5. The control method according to claim 4, characterized in that: When the microbial agent is a liquid agent, the application concentration is OD 600 =0.4-0.

6.

6. The control method according to claim 4 or 5, characterized in that: The control method specifically comprises the following steps: (1) Apply earthworm fertilizer 7-15 days after the kiwifruit plants enter the leaf-falling period; (2) Apply fermented yellow water 15-30 days after the plant ends its dormancy period; (3) Apply the microbial agent according to claim 1 or 2 on the 1st to 10th day after the plants enter the budding stage.

7. The control method according to claim 6, characterized in that: The earthworm fertilizer is applied by trenching and fertilizing and then covered with soil, and the application amount is 1.8-2.5t / mu; Preferably, the method for preparing the fermented yellow water is to aerobically ferment the yellow water at 23-28 for 7-10 days and then mix it with water in a volume ratio of 1:(7-14) to obtain the fermented yellow water; Preferably, the fermented yellow water is applied by spraying on the soil surface, and the application amount is 1.8-2.5t / mu.

8. The control method according to claim 6, characterized in that: The microbial agent is applied by digging trenches for fertilization and then covering with soil for landfill, and the application amount is 0.5-1 t / mu.

9. The control method according to claim 6, characterized in that: In step (1), decomposed organic fertilizer is applied to the kiwifruit plants 15-25 days before the kiwifruit plants enter the leaf-falling period; Preferably, the decomposed organic fertilizer is applied by trenching and then covered with soil for landfill, and the application amount is 1.8-3.2t / mu; Preferably, nitrogen fertilizer is applied on the 15th to 30th day after the plants end their dormancy period in step (2), with an application rate of 5 to 12 kg / mu.

10. The control method according to claim 6, characterized in that: In step (1), a fungicide is also applied before applying the earthworm fertilizer; Preferably, the fungicide comprises cymoxanil mancozeb.

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