A composition, biological agent, and its application and method for promoting lignification of fleshy root systems in fruit trees and / or preventing root rot in fruit trees.

Abstract

This invention relates to the field of plant protection technology, and in particular to a composition, biological agent, application, and method for promoting lignification of fleshy root systems in fruit trees and / or preventing root rot in fruit trees. The composition of this invention comprises component 1 and component 2; component 1 comprises a microbial agent and a plant extract, with a mass ratio of 20-50:30-44; the microbial agent comprises one or more of *Bacillus mucilaginosus*, *Trichoderma harzianum*, and *Beauveria bassiana*; the plant extract is prepared from one or more of willow bark, begonia blossoms, pomegranate peel, *Pseudomonas aeruginosa* bark, and neem bark; the active ingredient of component 2 is potassium humate. The composition of this invention can both promote root lignification and growth in plants and prevent root rot in fruit trees, and has the advantages of thorough treatment, low recurrence rate, no impact on fruit quality, and no harm to humans.

Description

Technical Field

[0001] This invention relates to the field of plant protection technology, and in particular to a composition, biological agent, and its application and method for promoting lignification of fleshy root systems in fruit trees and / or preventing root rot in fruit trees. Background Technology

[0002] Avocado root rot is a devastating disease in avocado cultivation, primarily caused by root damage. Currently, prevention and control of avocado root rot mainly involve strengthening orchard management, isolation and soil disinfection, and chemical control. However, treatment effectiveness varies and is time-consuming and labor-intensive. For example, chemical control involves the extensive use of chemical agents during the disease's onset to suppress root rot, but its treatment is often incomplete, recurrence is common, and it significantly impacts fruit quality. Furthermore, some chemicals are highly toxic and have long-lasting residual effects, posing health risks.

[0003] The main cause of root rot in avocados is that the fruit tree's fleshy roots are susceptible to pests and diseases, primarily due to their weak disease resistance. Conventional methods to promote root growth include applying plant growth regulators such as naphthaleneacetic acid, gibberellin, and indoleacetic acid. However, currently, there is no drug that can both promote root lignification and growth and prevent root rot in fruit trees. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a composition, biological agent, and its application and method for promoting lignification of fleshy root systems in fruit trees and / or preventing root rot in fruit trees. The composition of this invention not only promotes root lignification and growth but also prevents root rot in fruit trees, offering advantages such as thorough treatment, low recurrence rate, no impact on fruit quality, and no harm to human health.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention provides a composition for promoting lignification of fleshy root systems in fruit trees and / or preventing root rot in fruit trees, the composition comprising component 1 and component 2;

[0007] Component 1 includes a microbial agent and a plant extract; the mass ratio of the microbial agent to the plant extract is 20-50:30-44.

[0008] The microbial agent includes one or more of Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana.

[0009] The raw materials for preparing the plant extract include one or more of the following: willow bark, begonia flower, pomegranate peel, neem bark, and chinaberry bark.

[0010] The active ingredient of component 2 includes potassium humate.

[0011] Preferably, when the microbial agent includes Bacillus jellyoidus, Trichoderma harzianum, and Beauveria bassiana, the mass ratio of Bacillus jellyoidus, Trichoderma harzianum, and Beauveria bassiana is 5-15:10-20:1-15; the effective viable count of Bacillus jellyoidus is ≥10 billion / g, the effective viable count of Trichoderma harzianum is ≥2 billion / g, and the effective viable count of Beauveria bassiana is ≥10 billion / g;

[0012] When the raw materials for preparing the plant extract include willow bark, begonia flowers, pomegranate peel, neem bark, and chinaberry bark, the mass ratio of the willow bark, begonia flowers, pomegranate peel, neem bark, and chinaberry bark is 50-80:10-30:40-60:15-35:45-75.

[0013] When the raw materials for preparing the plant extract include willow bark, begonia flowers, pomegranate peel, and neem bark, the mass ratio of the begonia flowers, pomegranate peel, neem bark, and chinaberry bark is 10-30:40-60:50-85:40-65;

[0014] When the raw materials for preparing the plant extract include begonia flowers, pomegranate peel, neem bark and chinaberry bark, the preferred mass ratio of begonia flowers, pomegranate peel, neem bark and chinaberry bark is 10-30:40-60:50-85:40-65;

[0015] When the raw materials for preparing the plant extract include willow bark, begonia flowers, pomegranate peel, and neem bark, the mass ratio of the willow bark, begonia flowers, pomegranate peel, and neem bark is 50-80:10-30:10-30:50-85.

[0016] When the raw materials for preparing the plant extract include willow bark, begonia flowers, neem bark, and chinaberry bark, the mass ratio of the willow bark, begonia flowers, neem bark, and chinaberry bark is 50-80:10-30:40-60:50-85.

[0017] When the raw materials for preparing the plant extract include willow bark, pomegranate peel, neem bark, and chinaberry bark; the mass ratio of the willow bark, pomegranate peel, neem bark, and chinaberry bark is 50-80:40-60:50-85:40-65; when the raw materials for preparing the plant extract include willow bark, begonia flowers, and pomegranate peel, the mass ratio of the willow bark, begonia flowers, and pomegranate peel is 50-80:10-30:40-60.

[0018] When the raw materials for preparing the plant extract include pomegranate peel, neem bark and chinaberry bark, the mass ratio of pomegranate peel, neem bark and chinaberry bark is 20-45:30-65:15-45;

[0019] When the raw materials for preparing the plant extract include begonia flowers, pomegranate peel and euphorbia bark, the mass ratio of begonia flowers, pomegranate peel and euphorbia bark is 45-80:20-45:30-60;

[0020] When the raw materials for preparing the plant extract include willow bark, *Pseudolarix amabilis* bark, and *Melia azedarach* bark, the mass ratio of the willow bark, *Pseudolarix amabilis* bark, and *Melia azedarach* bark is 35–60:45–80:15–45.

[0021] When the raw materials for preparing the plant extract include willow bark and begonia flowers, the mass ratio of the willow bark to the begonia flowers is 85-120:75-110.

[0022] When the raw materials for preparing the plant extract include pomegranate peel and Pseudolarix amabilis bark, the mass ratio of pomegranate peel to Pseudolarix amabilis bark is 75-115:120-155;

[0023] When the raw materials for preparing the plant extract include willow bark and neem bark, the mass ratio of the willow bark to the neem bark is 85-120:45-65.

[0024] When the raw materials for preparing the plant extract include willow bark and pomegranate peel, the mass ratio of the willow bark to the pomegranate peel is 85-120:75-115;

[0025] When the raw materials for preparing the plant extract include begonia flowers and pomegranate peel, the mass ratio of begonia flowers to pomegranate peel is 75-110:75-115.

[0026] Preferably, the method for preparing the plant extract includes the following steps:

[0027] The raw materials were boiled to obtain a plant extract.

[0028] Preferably, the boiling process is carried out 2 to 3 times, and each boiling session lasts 2 to 3 hours; the amount of water used in each boiling session is 2 to 4 times the mass of the raw materials.

[0029] This invention provides a biological agent that promotes lignification of fleshy root systems in fruit trees and / or prevents root rot in fruit trees, the biological agent comprising the composition described in the above technical solution.

[0030] The present invention provides the application of the composition or preparation described in the above-mentioned technical solution in promoting the lignification of fleshy root systems in fruit trees and / or preventing root rot in fruit trees.

[0031] Preferably, the fruit tree with fleshy roots includes the avocado tree.

[0032] The present invention provides a method for promoting lignification of the roots of fruit trees with fleshy roots and / or preventing root rot in fruit trees, comprising: applying the composition or the preparation described in the above-mentioned technical solution after the fruit trees with fleshy roots have been planted.

[0033] Preferably, the amount of microbial agent applied in the composition or preparation is 500-600 g / 667 m³. 2 667m 2 The mass ratio of the applied microbial agent to the plant extract is 20–50:30–44, and the application rate of component 2 is 200–300 g / 667 m³. 2 .

[0034] Preferably, the application method of the microbial agent includes drip irrigation or deep application, the application method of the plant extract includes drip irrigation deep application or watering, and the application method of component 2 includes drip irrigation, sprinkler irrigation, watering or spraying.

[0035] Beneficial Effects: This invention provides a composition for promoting root lignification and / or preventing root rot in fruit trees. The composition comprises component 1 and component 2. Component 1 comprises a microbial agent and a plant extract. The mass ratio of the microbial agent to the plant extract is 20-50:30-44. The microbial agent comprises one or more of Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana. The raw materials for preparing the plant extract include one or more of willow bark, begonia flower, pomegranate peel, Pseudolarix amabilis bark, and Melia azedarach bark. The active ingredient of component 2 comprises potassium humate. Plant extracts have bactericidal and root lignification-promoting effects, microbial agents have bactericidal and insecticidal effects, and potassium humate is a nutrient source. This invention combines plant extracts, microbial agents, and potassium humate, creating a synergistic effect. The microbial agents and plant extracts work together to prevent root rot while providing sufficient nutrition to the plants, further improving the lignification of the fruit tree's fleshy roots and reducing root damage, especially in avocados. It can also effectively inhibit harmful pathogens and prevent soil-borne diseases and pests, thereby protecting the growth of fruit trees.

[0036] Moreover, the composition of the present invention has the advantages of thorough treatment, low recurrence rate, no impact on fruit quality, and no harm to the human body. It also provides a new approach to the prevention and control of avocado root rot. Detailed Implementation

[0037] Unless otherwise specified, all components described in this invention are readily available to those skilled in the art.

[0038] This invention provides a composition for promoting root lignification and / or preventing root rot in fruit trees. The composition comprises component 1 and component 2. Component 1 comprises a microbial agent and a plant extract. The mass ratio of the microbial agent to the plant extract is 20–50:30–44, more preferably 22–48:32–42, more preferably 25–45:35–40, and most preferably 35:38. The active ingredient of component 2 includes potassium humate. The composition of this invention also preferably comprises separately packaged components 1 and 2, more preferably separately packaged microbial agent, plant extract, and potassium humate. In this invention, the fulvic acid in the potassium humate is a small-molecule organic fertilizer absorbed by plants, which can improve the physical and chemical properties of the soil, form a granular structure, and facilitate aeration. The potassium in the potassium humate promotes the circulation of nutrients within the tree, creating a favorable microenvironment for root growth and development, thereby promoting the absorption and transport of nutrients by new roots and facilitating the absorption of organic fertilizer by fruit trees, thus improving tree vigor. In this invention, the fruit trees preferably include fruit trees with fleshy roots, and more preferably include avocado fruit trees.

[0039] The microbial agent of the present invention includes one or more of Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana, preferably including Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana. When the microbial agent of the present invention includes Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana, the mass ratio of Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana is preferably 5-15:10-20:1-15, more preferably 8-14:2-18:6-14, and even more preferably 10-12:14-16:8-12.

[0040] That is, when the microbial agent of the present invention includes *Bacillus mucilaginosus*, *Trichoderma harzianum*, and *Beauveria bassiana*, the microbial agent of the present invention preferably includes 5-15 parts of *Bacillus mucilaginosus* by weight, more preferably 8-14 parts, more preferably 10-12 parts, and most preferably 10 parts. In the present invention, the *Bacillus mucilaginosus* is preferably an agricultural *Bacillus mucilaginosus* agent; the effective viable count of the *Bacillus mucilaginosus* is preferably ≥10 billion / g. The present invention, by applying *Bacillus mucilaginosus* to the soil, can form a beneficial microbial community with the roots of fruit trees in the soil, supplementing the soil with a large number of beneficial microorganisms. The cytokinins, gibberellins, and other physiologically active substances secreted by this strain promote the lignification of fruit tree roots, enhance the disease resistance and root growth of fruit trees, inhibit the reproduction of harmful and pathogenic microorganisms in the soil, and effectively prevent root rot; moreover, this strain has the function of fixing nitrogen and releasing soil nutrients, and is a microbial culture powder.

[0041] Based on the mass fraction of the gelatinous Bacillus, the fungal agent of the present invention preferably includes 10-20 parts of Trichoderma harzianum, more preferably 12-18 parts, more preferably 14-16 parts, and most preferably 15 parts. The Trichoderma harzianum of the present invention is preferably an agricultural-grade Trichoderma harzianum agent; the effective viable count of the Trichoderma harzianum is preferably ≥2 billion / g. Trichoderma harzianum is a broad-spectrum fungicide. After being applied to the soil, Trichoderma harzianum of the present invention can grow rapidly on the root surface of fruit trees, effectively preventing pathogens from contacting the plant roots, thereby protecting the fruit tree roots from pathogen infection. Simultaneously, Trichoderma harzianum secretes antibiotics and other compounds that induce plant defense responses, which can inhibit the growth and colonization of pathogens and improve the root microenvironment, enhancing the growth and disease resistance of fruit trees.

[0042] Based on the mass fraction of the aforementioned *Bacillus jellyoides*, the fungal agent of this invention preferably includes 5-15 parts of *Beauveria bassiana*, more preferably 6-14 parts, even more preferably 8-12 parts, and most preferably 10 parts. The *Beauveria bassiana* of this invention is preferably an agricultural-grade *Beauveria bassiana* agent; the effective viable count of the *Beauveria bassiana* is preferably ≥10 billion / g. The *Beauveria bassiana* of this invention is an entomopathogenic fungus that can invade insects to achieve the effect of controlling pests; *Beauveria bassiana* is significantly effective against soil-borne pests, and is non-toxic, odorless, non-polluting, and residue-free. After application, it can continuously reproduce and grow in the soil, providing long-term control. When used in combination with *Bacillus jellyoides* and *Trichoderma harzianum*, it can control root rot in fruit trees while preventing soil-borne pests and stimulating root growth and development in fruit trees.

[0043] In existing technologies, microbial agents are often applied alone. This invention combines three microbial agents with different functions, providing insecticidal, fungicidal, and nutrient-providing effects in a synergistic manner. The resulting comprehensive effect not only prevents root rot in planted fruit trees, ensuring their healthy growth, but also offers some control over other soil-borne pests and diseases, especially avocados. The principle behind this invention's use of the three microbial agents is to utilize the interaction between the fruit tree's root system and various harmless microbial communities (Bacillus mucilaginosus, Trichoderma harzianum, and Beauveria bassiana) to regulate the lignification degree of the fruit tree's roots, thereby enhancing the root system's resistance to pathogens. This method is non-toxic, harmless, and highly effective.

[0044] In this invention, the mass of 1 mL of the plant extract is preferably 1 g. The raw materials for preparing the plant extract of this invention preferably include one or more of willow bark, begonia flowers, pomegranate peel, *Pseudolarix amabilis* bark, and neem bark, more preferably willow bark, begonia flowers, and pomegranate peel; the mass ratio of willow bark, begonia flowers, and pomegranate peel is 50–80:10–30:40–60, more preferably 55–75:15–25:45–55. In this invention, *Pseudolarix amabilis* bark and neem bark have insect-repellent effects, but they are both pharmaceutical raw materials, with relatively high usage costs, making large-scale promotion in the future inconvenient. Therefore, willow bark, begonia flowers, and pomegranate peel are more recommended.

[0045] When the raw materials for preparing the plant extract of the present invention include five kinds of raw materials, the preferred materials are willow bark, begonia flower, pomegranate peel, neem bark, and chinaberry bark; the preferred mass ratio of the willow bark, begonia flower, pomegranate peel, neem bark, and chinaberry bark is 50-80:10-30:40-60:15-35:45-75, and more preferably 45-85:5-35:35-65:10-40:40-80.

[0046] When the raw materials for preparing the plant extract of the present invention include four kinds of raw materials, the preferred materials are willow bark, begonia flower, pomegranate peel and neem bark, or begonia flower, pomegranate peel, neem bark and chinaberry bark, or willow bark, begonia flower, pomegranate peel and chinaberry bark, or willow bark, begonia flower, neem bark and chinaberry bark, or willow bark, pomegranate peel, neem bark and chinaberry bark. The preferred mass ratio of willow bark, begonia flower, pomegranate peel, and neem bark in this invention is 50-80:10-30:40-60:50-85, more preferably 42-83:7-33:37-63:47-82; the preferred mass ratio of begonia flower, pomegranate peel, neem bark, and chinaberry bark is 10-30:40-60:50-85:40-65, more preferably 15-35:35-55:45-80:35-60; the preferred mass ratio of willow bark, begonia flower, pomegranate peel, and chinaberry bark is 50-80:10-30: The preferred mass ratio of willow bark, begonia blossom, neem bark, and chinaberry bark is 50-80:10-30:40-60:50-85, more preferably 53-77:13-27:43-57:53-82; the preferred mass ratio of willow bark, pomegranate peel, neem bark, and chinaberry bark is 50-80:40-60:50-85:40-65, more preferably 53-87:43-57:53-82.

[0047] When the raw materials for preparing the plant extract of the present invention include three raw materials, the preferred materials are willow bark, begonia flowers, and pomegranate peel; or pomegranate peel, sedge bark, and chinaberry bark; or begonia flowers, pomegranate peel, and sedge bark; or willow bark, sedge bark, and chinaberry bark; the preferred mass ratio of willow bark, begonia flowers, and pomegranate peel is 50-80:10-30:40-60, more preferably 55-75:15-25:45-55; the preferred mass ratio of pomegranate peel, sedge bark, and chinaberry bark is... The preferred ratio is 20–45:30–65:15–45, more preferably 25–40:35–60:20–40; the preferred mass ratio of the begonia flowers, pomegranate peel, and neem bark is 45–80:20–45:30–60, more preferably 50–85:25–50:35–65; the preferred mass ratio of the willow bark, neem bark, and chinaberry bark is 35–60:45–80:15–45, more preferably 40–65:50–85:20–50.

[0048] When the raw materials for preparing the plant extract of the present invention include two raw materials, the preferred materials are willow bark and begonia flowers, or pomegranate peel and neem bark, or willow bark and chinaberry bark, or willow bark and pomegranate peel, or begonia flowers and pomegranate peel; the preferred mass ratio of willow bark to begonia flowers is 85-120:75-110, more preferably 90-125:80-115; the preferred mass ratio of pomegranate peel to neem bark is 75-115:120-15. 5. More preferably, the ratio is 80-120:125-160; the preferred mass ratio of willow bark to neem bark is 85-120:45-65, more preferably 90-125:50-70; the preferred mass ratio of willow bark to pomegranate peel is 85-120:75-115, more preferably 90-125:80-120; the preferred mass ratio of begonia flowers to pomegranate peel is 75-110:75-115, more preferably 80:120.

[0049] When the raw materials for preparing the plant extract of the present invention preferably include willow bark, begonia flowers, and pomegranate peel, the raw materials preferably include 50-80 parts of willow bark, more preferably 55-75 parts, and most preferably 55 parts. Based on the mass parts of the willow bark, the raw materials preferably include 10-30 parts of begonia flowers, more preferably 15-25 parts, and most preferably 25 parts. Based on the mass parts of the willow bark, the raw materials preferably include 40-60 parts of pomegranate peel, more preferably 45-55 parts, and most preferably 55 parts.

[0050] In this invention, the percentage by mass of the microbial agent and the percentage by mass of the raw material extracted by the plant extract can be different.

[0051] In this invention, the willow bark is preferably taken from the bark of willow trunks; more preferably, it is taken from willow bark with a growth cycle of 3 years or more, as the bark at this stage has a higher content of salicylic acid, resulting in better insect-repellent properties; even more preferably, the bark of willow trunks with a growth cycle of 3 years or more is broken into small pieces, sprayed with water to clean it, and then sun-dried for 2 days before use. Willow bark is rich in salicylic acid, which can promote the root growth of fruit trees and increase the lignification of the roots. It also contains salicylic acid and aspirin, which can promote root and sprouting of plants, as well as have antibacterial, anti-inflammatory, and antiseptic effects.

[0052] In this invention, the begonia flower is preferably the flower of the begonia, a perennial herbaceous plant of the Begoniaceae family. In addition to trace elements and amino acids, begonia flowers also contain oxalic acid, flavonoids, and sterols. According to the "Compendium of Materia Medica Supplement", it has the effects of clearing heat and detoxifying, reducing swelling and promoting tissue regeneration, and has the effect of assisting in killing insects. A certain amount of oxalic acid can improve the lignification degree of fruit tree roots.

[0053] In this invention, pomegranate peel is preferably the peel of the pomegranate fruit, more preferably harvested in autumn when the pomegranate fruit is ripe and the top splits open. The seeds and septa are removed, and the peel is cut into segments and sun-dried or dried over a low flame. Thick, reddish-brown pomegranate peel is selected for use. The pomegranate peel described in this invention has broad-spectrum antibacterial effects. The Chinese Pharmacopoeia records its hemostatic and anthelmintic properties. Furthermore, pomegranate peel inhibits the growth of various pathogenic bacteria, and its water extract shows significant inhibitory effects on the growth of various putrefactive fungi.

[0054] In this invention, the raw materials used for preparation are all common plant residues. The combined use of these raw materials after boiling can prevent root rot in fruit trees, promote lignification of the fruit tree roots, and prevent soil-borne pests.

[0055] The present invention preferably also provides a method for preparing the plant extract, comprising the following steps: boiling the raw materials to obtain the plant extract. In this invention, it is preferable to pulverize each raw material before boiling; willow bark, pomegranate peel, *Pseudolarix amabilis* bark, and *Melia azedarach* bark are preferably pulverized into small particles with a particle size of 2-3 mm; begonia flowers are preferably pulverized into powder. The present invention does not impose any requirements on the pulverization method; any method well known to those skilled in the art can be used. The present invention pulverizes the raw materials into small particles to facilitate the extraction of the plant extract, maximizing the extraction of the effective components.

[0056] This invention preferably involves mixing the extracts obtained from each decoction to obtain a plant extract. The decoction is preferably performed 2-3 times, more preferably 3 times. Each decoction is preferably performed for 2-3 hours, more preferably 2.5 hours. The amount of water used in each decoction is preferably 2-4 times the mass of the raw materials, more preferably 3 times. Under the decoction conditions provided by this invention, more salicylic acid can be obtained. The raw materials for the plant extract of this invention are all extracted from common plant residues, which have the advantages of being inexpensive and easy to collect. Furthermore, the decoction method is convenient and simple to operate. The plant extract has significant effects in disease prevention, insect repellency, sterilization, and preservation, and can also promote root lignification and growth.

[0057] The composition of this invention combines plant extracts with three different functional microbial agents and potassium humate to enhance the lignification of the fleshy roots of fruit trees, thereby reducing root damage. It also protects the growth of fruit trees, inhibits harmful pathogens, and prevents soil-borne diseases and pests.

[0058] This invention provides an agent for promoting root lignification and / or preventing root rot in fruit trees, the agent comprising the composition described in the foregoing technical solutions. The composition has been described in detail in the foregoing technical solutions, and therefore will not be repeated here. In this invention, the fruit trees preferably include those with fleshy roots, and more preferably include avocado trees.

[0059] Based on the above advantages, the present invention provides the application of the composition or preparation described in the above technical solution in promoting root lignification and / or preventing root rot in fruit trees. In the present invention, the fruit tree preferably includes a fruit tree with fleshy roots, and more preferably includes an avocado tree.

[0060] The present invention provides a method for promoting lignification of fruit tree roots and / or preventing root rot in fruit trees, comprising: applying the composition or preparation after the fruit trees are planted.

[0061] The present invention involves applying the aforementioned composition or preparation after the fruit trees are planted. The composition or preparation of the present invention has been discussed in detail in the foregoing technical solutions and will not be repeated here. In the present invention, the application rate of the microbial agent in the composition or preparation is 500–600 g / 667 m³. 2 Further preferred values ​​are 520–580 g / 667 m 2 It is also preferred to have a concentration of 540–560 g / 667 m 2 More preferably, 460–540 g / 667 m 2 ; per 667m 2The preferred mass ratio of the applied microbial agent to the plant extract is 20–50:30–44, more preferably 22–48:32–42, and even more preferably 25–45:35–40; the application amount of component 2 is 200–300 g / 667 m³. 2 More preferably, it is 220–280 g / 667 m 2 .

[0062] When components 1 and 2 are prepared and used immediately, this invention preferably drip-irrigates components 1 and 2 sequentially, and more preferably drip-irrigates the bacterial agent, plant extract, and component 2 sequentially. This invention does not impose any requirements on the drip irrigation method; any method well-known to those skilled in the art can be used. The drip irrigation method used in this invention has the advantages of saving water, fertilizer, and labor.

[0063] When components 1 and 2 are not freshly prepared and used, the present invention preferably applies the microbial agent, plant extract, and component 2 sequentially, or applies a mixture of the microbial agent and extract, followed by component 2 sequentially. The application method of the microbial agent preferably includes deep application; the suitable environment for the Bacillus silicoides, Trichoderma harzianum, and Beauveria bassiana described in the present invention is a low-temperature, low-ultraviolet, dry, and relatively humid environment, and they cannot be exposed to direct sunlight or excessive water shortage. Therefore, deep application is preferred, and sprinkler irrigation, watering, or spraying on the soil surface is not recommended; the application method of the plant extract preferably includes deep application or watering; the application method of component 2 preferably includes sprinkler irrigation, watering, or spraying. The main reason why non-freshly prepared bacterial agents and component 2 cannot be mixed is due to the preservation environment of the bacterial strains. In this case, if the bacterial agent is mixed with potassium humate or extract, it is very easy to cause large-scale death of the strains. The main reason why plant extracts cannot be mixed with potassium humate is that potassium humate is weakly alkaline, while plant extracts are acidic. The weakly alkaline potassium humate is prone to chemical reaction when mixed with acidic liquids, ultimately affecting the effect of the composition or biological agent. This invention does not have any requirements for the method of application; any method well known to those skilled in the art can be used. The preferred method of deep application in this invention includes trench application. Specifically, the preferred method is to apply the deep trench radially with the trunk as the central axis and the outer edge of the vertical projection of the crown as the trench length, which yields better results. In a specific embodiment of this invention, the preferred depth of deep application is 10 cm.

[0064] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0065] Example 1

[0066] 1. Preparation of biological agents

[0067] Preparation of Component 1

[0068] Inoculum: 1 part by weight is 45g, 10 parts (450g) of Bacillus jellyii (effective viable count ≥10 billion / g), 15 parts (675g) of Trichoderma harzianum (effective viable count ≥2 billion / g) and 10 parts (450g) of Beauveria bassiana (effective viable count ≥10 billion / g);

[0069] Extraction of plant extracts:

[0070] Assuming 1 part by weight is 30g, 55 parts (1650g) of willow bark and 55 parts (1650g) of pomegranate peel were mixed and crushed, and sieved into small particles of 2-3mm using a mesh sieve. 25 parts (750g) of begonia flowers were ground into powder. The three were mixed together, and twice the weight of the resulting mixture was added to each decoction. The mixture was decocted 3 times, each time for 2.5 hours. The extracts were mixed and filtered to obtain 1710mL of plant extract, which was then refrigerated.

[0071] The microbial agent was added to the above-obtained plant extract and stirred until homogeneous, wherein the mass ratio of the microbial agent to the plant extract was 35:38, to obtain component 1;

[0072] Component 2 is potassium humate, which was purchased from Heijinjing mineral source potassium humate humic acid water-soluble fertilizer.

[0073] 2. Application method

[0074] After the avocado trees are planted, components 1 and 2 are applied sequentially via drip irrigation. The dosage of the microbial agent in component 1 is 550g / 667m². 2 In component 1, the mass ratio of the bacterial agent to the plant extract is 35:38, and the amount of potassium humate is 240g / 667m³. 2 The water usage is 15 kg / 667 m³. 2 .

[0075] Example 2

[0076] The pot experiment was conducted at the Panzhihua Academy of Agricultural and Forestry Sciences in Sichuan Province, using the Has variety of avocado trees.

[0077] The Fusarium oxysporum standard strain used in this embodiment was provided by Ningbo Mingzhou Biotechnology Co., Ltd.

[0078] Comprehensive PDA agar medium: Peel 200g of potatoes, chop them, add 1000mL of water, simmer for 20 minutes, filter with gauze, add the filtrate to 1000mL, add 20g of glucose and 15g of agar, heat until melted, autoclave, and dispense into petri dishes to obtain comprehensive PDA agar medium.

[0079] The standard strain of Fusarium oxysporum was inoculated into a comprehensive PDA agar medium at an inoculation amount of 15%, and cultured at a temperature of 25–28°C for 5–8 days to obtain a culture solution with a viable count of 115,500 CFU / mL.

[0080] Thirty potted avocado seedlings with uniform growth were selected and artificially inoculated with root rot pathogens. The strain used was the standard strain of Fusarium oxysporum, simulating a root rot outbreak. The inoculation method was a field-based root-damage inoculation method. Without affecting the growth of the avocado, the soil around the avocado roots was completely dug up, wounds were created on the roots, the cultured strain was added to the wounds, and the soil was immediately covered and watered thoroughly. After inoculation, the avocado trees were cultured in their normal growing environment. Because the types and quantities of microorganisms in the soil were complex and the ratio between strains could not be determined, the growth factors of the microbial agent in the soil were not controlled separately.

[0081] Fifteen avocado trees were drip-irrigated with the biological agent prepared in Example 1, designated as the experimental group. The other 15 avocado trees were treated with conventional root rot control methods, namely organic fertilizer + fungicide, designated as the control group. The specific methods are as follows:

[0082] Experimental group: After planting avocado trees inoculated with root rot fungus, the fungal agent from Example 1 was applied deeply. The deep application method was as follows: radial deep trenches were made with the trunk as the central axis and the outer edge of the canopy's vertical projection as the trench length, with a depth of 10 cm and a dosage of 525 g / 667 m². 2 The calculated dosage of the microbial agent is 7g / plant. Simultaneously with the application of the microbial agent, the plant extract obtained in Example 1 and potassium humate are applied sequentially. The plant extract is applied to the roots in the morning, and the potassium humate is applied in the afternoon. The mass ratio of plant extract to potassium humate is 5:2, and the total dosage is 11.2g / plant. This translates to 8g / plant of plant extract and 3.2g / plant of potassium humate, meaning the total dosage of plant extract is 600g / 667m³. 2 The dosage of potassium humate is 240g / 667m. 2 The water usage is 15 kg / 667 m³. 2 After that, normal daily management will proceed.

[0083] Control group: After planting avocado trees inoculated with root rot fungus, the roots were drenched with organic fertilizer and pyraclostrobin in sequence. The organic fertilizer was diluted with water at a rate of 2.5 kg / plant (5 times dilution), stirred well, and then applied to the roots. This was done every 7 days for a total of 8 applications. The pyraclostrobin was applied at a rate of 35 mL / 667 m³. 2Root irrigation was carried out every 7 days for a total of 8 times, after which normal daily management was carried out; the organic fertilizer was "Zhuangtianxia" agricultural organic fertilizer produced by Henan Xinlianxiang Fertilizer Co., Ltd., and the pyraclostrobin-pyraclostrobin was "Lvfei" pyraclostrobin-pyraclostrobin produced by Syngenta, Switzerland.

[0084] The experimental group was observed for disease condition, root lignification degree, and growth on days 15, 30, 45, 60, and 75 after the application of potassium humate.

[0085] The control group was observed for disease condition, root lignification degree, and growth on days 15, 30, 45, 60, and 75 after the first root drenching with pyraclostrobin.

[0086] The results were as follows: In the control group, there were no obvious changes in the leaves of the avocado plants on day 15; on day 30, some leaves of the avocado plants drooped and wilted naturally; on day 45, some leaves of the avocado plants became lighter in color, new leaves became smaller, leaf tips withered and leaf edges curled; on day 60, the avocado plants had difficulty in sprouting new shoots, branches lost water and shrank, and branches suddenly withered; on day 75, a small number of leaves fell off and branches withered again. When the avocado roots were slowly rinsed with running water, it was found that the root tips and root branches were black and brittle.

[0087] In the experimental group, there were no obvious changes in the leaves of avocado plants on days 15 and 30. On day 45, some leaves of avocado plants drooped naturally and young leaves wilted. On day 60, the leaves of avocado plants turned yellow, the edges of young leaves curled, and new leaves became smaller. On day 75, some leaves of avocado plants turned green again and the leaves unfolded and became firm. The symptoms did not worsen significantly. When the roots of avocado plants were slowly rinsed with running water, it was found that the fibrous roots were all lignified with reddish-brown circular spots, the surface of the main root had a thin epidermis, and there were no obvious changes in the internal cortex and vascular cylinder.

[0088] Therefore, the composition described in this invention can effectively inhibit the growth of root rot fungi and promote the lignification of avocado tree roots.

[0089] Example 3

[0090] The field trial was conducted at the avocado planting base in Daqinggou, Panzhihua City, Sichuan Province, using the Has variety of avocado trees.

[0091] Twenty avocado trees infected with root rot were planted. The symptoms were browning and blackening of the avocado's fibrous roots. Ten trees were managed normally and were recorded as the control group. The other ten trees were treated with the preparation provided in Example 1 and were recorded as the experimental group. The specific method is as follows:

[0092] Experimental group: Panzhihua in March with normal climate. After planting, the application methods of the inoculant, plant extract and potassium humate in Example 1 were the same as those in the experimental group in Example 2. Then, routine water and fertilizer management was carried out.

[0093] Control group: Panzhihua has normal climate in March, and the watering frequency is once every 10 days.

[0094] After the experimental group was treated with potassium humate and plant extract, the disease condition and growth (root system observation) of the experimental group and the control group were observed on the 15th, 30th, 45th, 60th, 75th and 90th days.

[0095] The results were as follows: In the control group, on day 15, some avocado plants exhibited natural drooping and wilting; on day 30, the leaves turned a pale green or light yellow, new leaves became smaller, leaf tips turned brown and necrotic, leaf edges curled, and the overall tree vigor became loose; on day 45, new shoots had difficulty sprouting, branches lost water and shrank, and branches suddenly withered; on day 60, a small number of leaves fell off and branches withered again; on day 75, the top of the avocado plant died and a large number of leaves fell off; on day 90, the entire avocado plant dried up and died. On day 90, observation after slowly rinsing the avocado roots with running water revealed that the roots were black, completely rotten, and brittle.

[0096] On day 15, the leaves of the avocado plants in the experimental group showed no obvious changes. On day 30, some leaves drooped naturally and young leaves wilted. On day 45, the leaves turned yellow, the edges of young leaves curled, and new leaves became smaller. On day 60, some leaves turned green again and the leaves unfolded and became firm. On day 75, new shoots sprouted from the lower branches of the avocado plants. On day 90, the symptoms of the avocado plants were not significantly different from those on day 75. On day 90, after slowly rinsing the avocado roots with running water, it was observed that all the fibrous roots were lignified with reddish-brown circular spots. The surface of the main root had a thin, yellowish epidermis, the internal cortex was brown, and the vascular cylinder was white, indicating a greater degree of lignification of the roots.

[0097] Therefore, the composition described in this invention can effectively prevent and control root rot pathogens and promote lignification of avocado tree roots.

[0098] Example 4

[0099] The field trial was conducted at the Dalongtan Avocado Standardized Planting Base in Panzhihua City, Sichuan Province, using the Has variety of avocado trees.

[0100] Twenty avocado trees infected with root rot were selected, with symptoms including browning and blackening of the root hairs. Ten trees were treated with conventional root rot control methods, namely organic fertilizer + fungicide, and were designated as the control group. The other ten trees were treated with the preparation provided in Example 1 and were designated as the experimental group. The specific methods are as follows:

[0101] Experimental group: Panzhihua had normal climate in March. After planting, the application methods of the inoculant, plant extract and potassium humate in Example 1 were the same as those in the experimental group in Example 2. After that, normal daily management was carried out.

[0102] Control group: Same as in Example 2.

[0103] After the experimental group was treated with potassium humate and plant extract, the disease condition, root lignification degree, and growth were observed in both the experimental and control groups on days 15, 30, 45, 60, and 75.

[0104] The results were as follows: In the control group, there were no obvious changes in the leaves of the avocado plants on day 15; on day 30, some leaves of the avocado plants drooped and wilted naturally; on day 45, some leaves of the avocado plants became lighter in color, new leaves became smaller, leaf tips withered and leaf edges curled; on day 60, the avocado plants had difficulty in sprouting new shoots, branches lost water and shrank, and branches suddenly withered; on day 75, a small number of leaves fell off and branches withered. When the avocado roots were slowly rinsed with running water, it was found that the root tips and root branches were black and brittle.

[0105] In the experimental group, there were no obvious changes in the leaves of avocado plants on days 15 and 30. On day 45, some leaves of avocado plants drooped naturally and young leaves wilted. On day 60, the leaves of avocado plants turned yellow, the edges of young leaves curled, and new leaves became smaller. On day 75, some leaves of avocado plants turned green again and the leaves unfolded and became firm. The symptoms did not worsen significantly. When the roots of avocado plants were slowly rinsed with running water, it was found that the fibrous roots were all lignified with reddish-brown circular spots, the surface of the main root had a thin epidermis, and there were no obvious changes in the internal cortex and vascular cylinder.

[0106] Therefore, the composition described in this invention can effectively inhibit the growth of root rot fungi and promote the lignification of avocado tree roots.

[0107] In summary, the biological agent described in this invention can promote the lignification and growth of plant roots, prevent root rot in fruit trees, and has the advantages of thorough treatment, low recurrence rate, no impact on fruit quality, and no harm to the human body.

[0108] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A composition for promoting lignification of fleshy root systems in fruit trees and preventing root rot in fruit trees, characterized in that, The composition comprises component 1 and component 2; Component 1 includes a microbial agent and a plant extract; The mass ratio of the bacterial agent to the plant extract is 20~50:30~44; The bacterial agent is Bacillus jellyoidis, Trichoderma harzianum, and Beauveria bassiana; The raw materials for preparing the plant extract are willow bark, begonia flowers, and pomegranate peel; The active ingredient of component 2 includes potassium humate; The preparation method of the plant extract includes the following steps: The raw materials were boiled to obtain a plant extract.

2. The composition according to claim 1, characterized in that, The mass ratio of the gelatinous Bacillus, Trichoderma harzianum, and Beauveria bassiana is 5~15:10~20:1~15; the effective viable count of the gelatinous Bacillus is ≥10 billion / g, the effective viable count of Trichoderma harzianum is ≥2 billion / g, and the effective viable count of Beauveria bassiana is ≥10 billion / g. The mass ratio of willow bark, begonia flowers, and pomegranate peel is 50-80:10-30:40-60.

3. The composition according to claim 1, characterized in that, The boiling process is repeated 2 to 3 times, with each boiling session lasting 2 to 3 hours. The amount of water used in each boiling session is 2 to 4 times the mass of the raw materials.

4. A biological agent that promotes lignification of fleshy root systems in fruit trees and prevents root rot, characterized in that, The biological agent includes the composition according to any one of claims 1 to 3.

5. The application of the composition according to any one of claims 1 to 3 or the biological agent according to claim 4 in promoting lignification of fleshy root systems in fruit trees and preventing root rot in fruit trees, characterized in that, The fruit tree with fleshy roots is the avocado tree.

6. A method for promoting lignification of fleshy root systems in fruit trees and preventing root rot, characterized in that, include: After the fruit trees with fleshy roots are planted, apply the composition according to any one of claims 1 to 3 or the biological agent according to claim 4; The fruit tree with fleshy roots is the avocado tree.

7. The method according to claim 6, characterized in that, The dosage of the microbial agent in the composition or biological agent is 500-600g / 667m. 2 667m 2 The mass ratio of the applied microbial agent to the plant extract is 20-50:30-44, and the application rate of component 2 is 200-300 g / 667 m³. 2 .

8. The method according to claim 6 or 7, characterized in that, The application methods of the microbial agent include drip irrigation or deep application, the application methods of the plant extract include drip irrigation, deep application or watering, and the application methods of component 2 include drip irrigation, sprinkler irrigation, watering or spraying.