A compound microbial agent for preventing and treating leek blight and a method of using the same
The use of compound microbial agents has solved the problem of leek blight prevention and control, achieved the goal of green planting, and avoided environmental pollution and drug resistance risks associated with chemical agents.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- MILE CITY AGRI TECH EXTENSION CENT
- Filing Date
- 2026-03-17
- Publication Date
- 2026-06-12
AI Technical Summary
Current technology lacks effective and safe agents for controlling leek blight. The use of chemical agents leads to environmental pollution and drug resistance problems, and existing microbial agents are not very effective.
A compound microbial agent, composed of palm leaf fermentation broth, modified starch, caffeine, maltodextrin, and sodium benzoate, is used to control leek blight by spraying with Bacillus subtilis, Bacillus vesicola, Rhodotorula rubra, and Trichoderma harzianum.
Effectively prevent and control leek blight, reduce the harm of chemical agents, achieve green planting, ensure the normal growth of leeks, and reduce the pollution of chemical agents to the environment and soil.
Smart Images
Figure CN122181553A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of microbial pesticide technology, specifically to a compound microbial agent for the prevention and control of leek blight and its application method. Background Technology
[0002] Phytophthora blight of chives is generally caused by Phytophthora infestans, a fungal disease commonly affecting the roots, stems, leaves, flowers, and scapes of chives. The pseudostems and bulbs are most severely affected. The disease thrives in hot and humid environments. After infection, sporangia are produced on the affected areas, leading to repeated infections. The diseased areas constrict due to dehydration, causing rot in the leaves, pseudostems, and roots, inhibiting plant growth and resulting in severe yield reduction. On chive leaves, the disease typically starts in the lower middle parts, initially appearing as dark green, water-soaked lesions or yellow spots. These lesions later constrict, wilt, and rot. When the lesions extend to half the leaf surface, the leaves turn yellow from the tip, droop, and soften. Phytophthora blight is currently one of the most significant diseases affecting chive production.
[0003] Currently, there are no officially registered pesticides for the prevention and control of leek blight in China. In actual cultivation, most pesticides are used for control, such as cymoxanil-mancozeb wettable powder. However, cymoxanil-mancozeb has a short residual period and easily induces resistance in pathogens, while mancozeb can easily harm aquatic organisms. Furthermore, the use of chemical pesticides can lead to pesticide residues and environmental pollution. At present, in order to achieve the goal of green planting, microbial agents and other methods have been gradually adopted for the prevention and control of plant diseases and pests. Therefore, it is crucial to develop a safe and effective microbial agent for leek blight. Summary of the Invention
[0004] To address the shortcomings of existing technologies, this invention provides a compound microbial agent for preventing and controlling leek blight and its application method, which effectively prevents and controls leek blight, ensures the normal growth of leeks, reduces the harm of chemical agents, and achieves green planting.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A compound microbial agent for preventing and controlling leek blight, the compound microbial agent being composed of the following raw materials in parts by weight: 30-40 parts palm leaf fermentation liquid, 0.02-0.04 parts compound microorganisms, 1-2 parts modified starch, 0.4-0.6 parts caffeine, 1-2 parts maltodextrin, and 0.06-0.08 parts sodium benzoate; the palm leaf fermentation liquid is obtained by fermenting the filter residue after alcohol extraction of palm leaves with *Salmonella spp.* and then pressing it; the compound microorganisms are obtained by mixing *Bacillus subtilis*, *Bacillus belye*, *Rhodotorula rubrum*, and *Trichoderma harzianum* in a mass ratio of 2:2:1:1; the modified starch is obtained by steam-exploding corn starch and then microwave-setting it.
[0006] Preferably, the specific preparation method of the palm leaf fermentation broth includes the following steps: S1-1. Add palm leaves to a 60%-70% ethanol solution, grind and crush them, then extract them with alcohol for 1-2 hours, then press and filter them, and dry the filter residue to obtain pretreated palm material for later use. S1-2. Mix the pretreated palm material with brown sugar water at a mass ratio of 1:3-5, then inoculate with *Gastrodia elata*, ferment on a shaker for 28-32 hours, then press and filter, adjusting the *Gastrodia elata* concentration in the filtrate to 10... 7 -10 9 The number of cells / mL was used to obtain the palm leaf fermentation broth.
[0007] Preferably, the alcohol extraction conditions in step S1-1 are constant temperature water bath extraction at 40-50℃.
[0008] Preferably, the drying temperature in step S1-1 is 40-50℃.
[0009] Preferably, the mass concentration of brown sugar in the brown sugar water in steps S1-2 is 0.5%-0.8%.
[0010] Preferably, the temperature of the shaking fermentation treatment in step S1-2 is 25±2℃, and the rotation speed of the shaking table is 120-180r / min.
[0011] Preferably, the method for preparing the modified starch includes the following steps: S2-1. Treat corn starch with steam explosion at 180-200℃ for 2-4 minutes under 1-2 MPa pressure, and then remove it to obtain steam-exploded starch for later use. S2-2. The above-mentioned steam-exploded starch is treated at a power of 400-600W for 30-40s to obtain modified starch.
[0012] Preferably, the moisture content of the corn starch is adjusted to 20%-25% before steam explosion treatment.
[0013] Preferably, the method of using the compound microbial agent is characterized in that the compound microbial agent is diluted with water by 200-400 times and then sprayed, and sprayed once every 7-10 days, for a total of 2-4 times.
[0014] This invention provides a compound microbial agent for preventing and controlling leek blight and its application method, which has the following advantages compared with the prior art: This invention uses Bacillus subtilis, Bacillus belye, Rhodotorula rubrum, Trichoderma harzianum, and Sarcoptera thunbergii as the main disease control microorganisms. Among them, Sarcoptera thunbergii is prepared by fermenting palm leaves after alcohol extraction to further enhance the control effect on leek blight. At the same time, modified starch, caffeine, maltodextrin, and sodium benzoate are added in combination to effectively ensure the control effect on leek blight while ensuring the growth of leeks, reducing the pollution of the environment and soil by chemical agents, and realizing green planting. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of chive leaves in group 1 of this invention. Figure 2 This is a schematic diagram of chive leaves in group 2 of this invention. Figure 3 This is a schematic diagram of chive leaves in group 3 of this invention. Figure 4 This is a schematic diagram of chive leaves in group 4 of this invention. Figure 5 This is a schematic diagram of chive leaves in group 5 of this invention. Figure 6 This is a schematic diagram of chive leaves in group 6 of this invention. Figure 7 This is a schematic diagram of chive leaves in group 7 of this invention. Figure 8 A schematic diagram showing the growth of chives on April 2nd after spraying them with a 100-fold diluted suspension of pathogenic bacteria following transplanting; Figure 9 This is a schematic diagram of the growth of chives in group 8 in an embodiment of the present invention; Figure 10 This is a schematic diagram of the growth of chives in group 9 in an embodiment of the present invention. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0017] The following examples used *Gnaphalium affine* purchased from Ningbo Mingzhou Biotechnology Co., Ltd. (product number B67211); *Bacillus subtilis* purchased from Beijing Bio-BioBiotechnology Co., Ltd. (product number Bio-81826); *Bacillus belyssus* purchased from Beijing Bio-BioBiotechnology Co., Ltd. (product number Bio-84965); *Rhodotorula rubrum* purchased from Beijing Bio-BioBiotechnology Co., Ltd. (product number Bio-57573); *Trichoderma harzianum* purchased from Beijing Bio-BioBiotechnology Co., Ltd. (product number Bio-15596); and *Phytophthora nicotine* purchased from Shanghai Jiachu Bioengineering Co., Ltd. (product number SHBCC D10922).
[0018] Example 1: 1. Raw material preparation 1.1 Preparation of Palm Leaf Fermentation Broth: Fermentation broth A: Palm leaves were ground and pulverized in three times their volume of a 65% ethanol solution, then extracted with alcohol at a constant temperature of 45°C for 1.5 hours. After pressing and filtration, the filter residue was dried at 45°C to remove the solvent, yielding pretreated palm material. The pretreated palm material was mixed with brown sugar water (0.7% by mass) at a ratio of 1:4 and stirred thoroughly. Then, *Gnaphalium affine* (0.1% of the pretreated palm material by mass) was inoculated and fermented on a shaker for 30 hours (temperature 25±2°C, rotation speed 120 r / min). After pressing and filtration, the concentration of *Gnaphalium affine* in the filtrate was adjusted to 10... 8 Fermentation broth A was obtained by measuring 1 / mL of 1 / mL.
[0019] Fermentation broth B: Palm leaves were ground into a paste by mixing brown sugar water (0.7% by weight) at a ratio of 1:4. The paste was then inoculated with *Gnaphalium affine* (0.1% of the palm leaf weight) and fermented on a shaker for 30 hours (25±2℃, 120 r / min). The mixture was then pressed, filtered, and concentrated to adjust the *Gnaphalium affine* concentration in the filtrate to 10%. 8 Fermentation broth B was obtained by measuring cells / mL.
[0020] Fermentation broth C: The *Gastrobinacillus rubiginii* was mixed into a suspension in sterile water and activated at a constant temperature of 25°C. The concentration of *Gastrobinacillus rubiginii* in the activation solution was controlled at 10... 8 The fermentation broth C was obtained by measuring 1 / mL of 1 / mL.
[0021] 1.2 Preparation of modified starch: The moisture content of corn starch was adjusted to 25%, and then subjected to steam explosion treatment at 200℃ for 3 minutes under a pressure of 1 MPa. The steam explosion starch was then treated at 400W power for 40 seconds to obtain modified starch.
[0022] 1.3 Preparation of composite microorganisms: A composite microorganism was obtained by mixing Bacillus subtilis, Bacillus vesicularis, Rhodotorula rubra, and Trichoderma harzianum in a mass ratio of 2:2:1:1.
[0023] 2. Preparation of compound microbial agents: Mix the raw materials according to the following formulas (mass distribution ratios) to prepare different compound microbial agents: Microbial agent A: 35 parts fermentation broth A, 0.03 parts compound microorganisms, 1.5 parts modified starch, 0.5 parts caffeine, 1.5 parts maltodextrin, and 0.07 parts sodium benzoate.
[0024] Microbial agent B: 35 parts fermentation broth B, 0.03 parts compound microorganisms, 1.5 parts modified starch, 0.5 parts caffeine, 1.5 parts maltodextrin, and 0.07 parts sodium benzoate; Inoculant C: Fermentation broth C 35 parts, compound microorganisms 0.03 parts, modified starch 1.5 parts, caffeine 0.5 parts, maltodextrin 1.5 parts, sodium benzoate 0.07 parts; Inoculant D: 35 parts sterile water, 0.03 parts compound microorganisms, 1.5 parts modified starch, 0.5 parts caffeine, 1.5 parts maltodextrin, and 0.07 parts sodium benzoate; Inoculant E: Fermentation broth A 35 parts, compound microorganisms 0.03 parts, modified starch 1.5 parts, maltodextrin 1.5 parts, sodium benzoate 0.07 parts.
[0025] 3. Preparation of pathogen suspension: Phytophthora tobaccois was inoculated onto OA medium plates and incubated in the dark at 25°C for 7 days until the mycelium completely covered the plate. The mycelium was then cut into small pieces (2mm × 2mm) and added to petri dishes containing 10% V8 liquid medium, 30 pieces per dish. Incubation continued in the dark at 25°C for 3 days. The culture medium was removed, and the plates were rinsed three times with sterile water, changing the water twice daily for three consecutive days to induce the production of zoosporangia. Induction was stopped when there were more than 10,000 zoosporangia per square centimeter of mycelial block. The zoospore-producing mycelial blocks were then treated at 8°C for 20 minutes, then placed at room temperature for 20 minutes to induce the release of zoospores from the zoosporangia. Sterile water was added to the petri dishes, and the surface of the mycelial cake was repeatedly agitated with a pipette. The suspension was then transferred to sterile centrifuge tubes. The centrifuge tubes containing the suspension were vortexed for 2 minutes to remove as many flagella as possible from the zoospores. Each tube was then centrifuged at 2500 rpm to concentrate the suspension, removing the supernatant. The concentrated suspension was resuspended and concentrated again for later use. The number of zoospores was determined to be 10 using a hemocytometer. 6 A suspension of bacteria per mL was prepared as a pathogen suspension.
[0026] 4. Field experiments: 4.1 Disease Prevention Experiment Seven planting areas were set up in the greenhouse, with sterilized garden soil used as the planting substrate. Healthy chive roots from the same batch were transplanted routinely to each planting area on March 22, 2025. The day after transplanting, each planting area was sprayed with a different pesticide, followed by a 100-fold dilution of pathogen suspension every 6 hours. Repeat spraying was performed on March 31 and April 7. On April 20, the incidence rate of chives in each planting area was observed and recorded (incidence rate = total number of diseased plants / total number of plants), as well as the severe disease rate (severe disease rate = number of severely diseased plants / total number of diseased plants). The specific results are shown in Table 1 below. Table 1
[0027] Two chive plants were randomly selected from each group, and one diseased leaf was cut from each plant (if there were no diseased leaves, they were cut randomly). The condition of the leaves in each group is as follows: Figure 1-7As shown, overall, the incidence rate of leeks treated with a 500-fold dilution of 72% cymoxanil-mancozeb wettable powder was similar to that of fungicide A, but the leeks treated with fungicide A had fewer severe cases. In group 4, the fermentation broth of fungicide B, which did not undergo alcohol extraction of palm leaves, resulted in a higher incidence rate of blight. The effects of adding *Salmonella sibirica* suspension and water to fungicide C and fungicide D showed little difference in incidence rate, but the addition of *Salmonella sibirica* suspension could limit the rate of severe disease to some extent. In group 7, fungicide E, which reduced the addition of caffeine, also showed a higher incidence rate compared to group 3.
[0028] 5. Experiment on the therapeutic effect on the disease: Two planting areas were set up inside the greenhouse, with sterilized garden soil used as the planting substrate. Healthy chive roots from the same batch were transplanted routinely to each planting area on March 22, 2025. The day after transplanting, each planting area was sprayed with a 100-fold diluted pathogen suspension. After leaf spots appeared (April 2nd), Figure 8 Two planting areas were sprayed with water and a 300-fold diluted solution of inoculant A, respectively. The solution was then sprayed again at 7-day intervals. The disease severity rate of chives in each planting area was observed and recorded on April 20th. The specific results are shown in Table 2 below. Table 2
[0029] The extent of lesion expansion on chives in specific groups 8 and 9 is as follows: Figure 8 and Figure 9 As shown in the table above, applying a 300-fold diluted solution of fungal agent A can effectively inhibit the spread of lesions to a certain extent, achieving the purpose of treatment, and simultaneously reducing the incidence of severe disease.
[0030] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A compound microbial agent for preventing and controlling leek blight, characterized in that, The compound microbial agent is composed of the following raw materials in parts by weight: 30-40 parts palm leaf fermentation broth, 0.02-0.04 parts compound microorganisms, 1-2 parts modified starch, 0.4-0.6 parts caffeine, 1-2 parts maltodextrin, and 0.06-0.08 parts sodium benzoate; The palm leaf fermentation broth is obtained by pressing the filter residue after ethanol extraction of palm leaves after fermentation with *Salmonella spp.* The composite microorganisms were obtained by mixing Bacillus subtilis, Bacillus belye, Rhodotorula rubrum, and Trichoderma harzianum in a mass ratio of 2:2:1:
1. The modified starch is obtained by steam-exploding corn starch followed by microwave setting.
2. The compound microbial agent according to claim 1, characterized in that, The specific preparation method of the palm leaf fermentation broth includes the following steps: S1-1. Add palm leaves to a 60%-70% ethanol solution, grind and crush them, then extract them with alcohol for 1-2 hours, then press and filter them, and dry the filter residue to obtain pretreated palm material for later use. S1-2. Mix the pretreated palm material with brown sugar water at a mass ratio of 1:3-5, then inoculate with *Gastrodia elata*, ferment on a shaker for 28-32 hours, then press and filter, adjusting the *Gastrodia elata* concentration in the filtrate to 10... 7 -10 9 The number of cells / mL was used to obtain palm leaf fermentation broth.
3. The compound microbial agent according to claim 2, characterized in that: The alcohol extraction in step S1-1 is performed under constant temperature water bath extraction at 40-50℃.
4. The compound microbial agent according to claim 2, characterized in that: The drying temperature in step S1-1 is 40-50℃.
5. The compound microbial agent according to claim 2, characterized in that: In steps S1-2, the mass concentration of brown sugar in the brown sugar water is 0.5%-0.8%.
6. The compound microbial agent according to claim 2, characterized in that: In steps S1-2, the temperature of the shaker fermentation treatment is 25±2℃, and the rotation speed of the shaker is 120-180r / min.
7. The compound microbial agent according to claim 1, characterized in that, The method for preparing the modified starch includes the following steps: S2-1. Treat corn starch with steam explosion at 180-200℃ for 2-4 minutes under 1-2 MPa pressure, and then remove it to obtain steam-exploded starch for later use. S2-2. The above-mentioned steam-exploded starch is treated at a power of 400-600W for 30-40s to obtain modified starch.
8. The compound microbial agent according to claim 1, characterized in that: Before the corn starch undergoes steam explosion treatment, the moisture content is adjusted to 20%-25%.
9. A method of using the compound microbial agent as described in any one of claims 1-8, characterized in that, The method of application is to dilute the compound microbial agent with water 200-400 times and then spray it, spraying once every 7-10 days, for a total of 2-4 times.