Method for preventing and treating tobacco black shank and bacterial wilt

Abstract

The invention discloses a method for preventing and treating tobacco black shank and bacterial wilt, which comprises the following steps: S1, applying biochar to improve soil permeability: before tobacco seedlings are transplanted, mixing the biochar and a special compound fertilizer for flue-cured tobacco according to a ratio, uniformly stirring, and applying the mixture into soil to improve the soil permeability, cultivate developed root systems of tobacco plants and enhance the resilience of the tobacco plants; s2, increasing the number of effective microbial communities in soil by using a biological agent in combination with pesticide, wherein 3 days after tobacco seedlings are transplanted, a mixed preparation of mineral source potassium fulvic acid, bacillus subtilis and trichoderma harzianum is used for root irrigation; by applying a combination of specific biochar and a biological control preparation, the physical and chemical properties of tobacco field soil are effectively improved, the growth and development of flue-cured tobacco plants are promoted, and meanwhile, the disease resistance of the tobacco plants is remarkably enhanced; in field application, the prevention and control measure shows an excellent prevention and control effect on tobacco black shank and bacterial wilt.

Description

Technical Field

[0001] This invention relates to the field of mechanical technology, specifically to a method for preventing and controlling tobacco black shank disease and bacterial wilt. Background Technology

[0002] Tobacco black shank and bacterial wilt are two of the most serious soil-borne diseases in tobacco production, caused by *Phytophthora parasitica* var. *nicotianae* and *Pseudomonas azolanacearum*, respectively. In recent years, due to factors such as insufficient resistant varieties, significant soil-borne cropping obstacles, and the strong soil-borne nature of the pathogens, the frequency and severity of black shank and bacterial wilt have been increasing year by year. Furthermore, in actual tobacco field production, they often exhibit combined infection phenomena, significantly increasing the difficulty of disease identification and control, and becoming one of the key diseases seriously restricting tobacco leaf quality and yield.

[0003] Currently, the control of these two types of diseases mainly relies on a comprehensive approach including the breeding of resistant varieties, crop rotation, application of chemical pesticides, and biological control. However, with the long-term and widespread use of chemical pesticides, the problem of pathogen resistance is becoming increasingly serious, leading to the "3R" problems (resistance, residue, and reinfection) such as environmental pollution and excessive pesticide residues. Meanwhile, resistant varieties face resource scarcity and unstable resistance, making it impossible to fundamentally curb the continued development of the disease.

[0004] With the increasing emphasis on green agriculture and sustainable development, biological control technologies are gaining importance. Biochar, as a novel soil amendment, offers crucial support for building a green, efficient, and ecological tobacco disease control system due to its functions in improving soil physicochemical properties, enhancing water and fertilizer retention, regulating soil pH, and promoting the reproduction of beneficial microorganisms. Meanwhile, the potential of natural plant-derived pesticides and beneficial microorganisms in controlling black shank and bacterial wilt is being increasingly demonstrated. However, their field application effectiveness remains susceptible to influences from soil structure, environmental conditions, and application methods. The lack of stable and efficient supporting field application techniques has become a key factor limiting their widespread adoption.

[0005] Therefore, there is an urgent need to develop a method for controlling tobacco black shank and bacterial wilt to improve the stability and field adaptability of biological control, thereby effectively alleviating the production losses caused by tobacco black shank and bacterial wilt and promoting the development of tobacco planting towards green, low-carbon and high-quality directions. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preventing and controlling tobacco black shank disease and bacterial wilt, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a method for preventing and controlling tobacco black shank disease and bacterial wilt, the method comprising the following steps:

[0008] S1. Apply biochar to improve soil permeability: Before transplanting tobacco seedlings, mix biochar with flue-cured tobacco-specific compound fertilizer in a certain proportion, mix well and apply to the soil to improve soil permeability, cultivate well-developed root systems of tobacco plants, and enhance the stress resistance of tobacco plants.

[0009] S2. Use biological agents in combination to increase the number of beneficial bacteria in the soil: Three days after transplanting tobacco seedlings, use a mixture of mineral-derived potassium humate, Bacillus subtilis and Trichoderma harzianum for root irrigation.

[0010] S3. Intercropping with mint to optimize soil ecology: Within one week after the tobacco seedlings are transplanted, select healthy mint plants free from pests and diseases as mother plants. Cut the mint runners into several sections, each containing at least one node, and bury them in the soil between every two tobacco seedlings.

[0011] Preferably, the ratio of biochar to flue-cured tobacco compound fertilizer in S1 is 1:0.5 to 1:1.

[0012] Preferably, the biochar is a harmless carbon source produced by high-temperature carbonization of organic matter, and has strong adsorption and water and fertilizer retention properties.

[0013] Preferably, the amount of root irrigation solution used per plant in S2 is 1000 ml, and it is used three times consecutively, with an interval of 15 days between each application.

[0014] Preferably, the biological agent comprises a combination of potassium humate, Bacillus subtilis, and Trichoderma harzianum, wherein Bacillus subtilis is used to inhibit the growth of pathogens, and Trichoderma harzianum is used to decompose organic matter in the soil and promote the proliferation of beneficial soil bacteria.

[0015] Preferably, in S3, the plant spacing is 15 cm, and 2-3 mint runners are planted for every two tobacco seedlings.

[0016] Preferably, the planting nodes of the mint stolons are buried in the soil at a depth of 3-5 cm, with the stems and leaves on the nodes facing upwards and exposed above the soil surface.

[0017] Preferably, the method is applied to all stages of flue-cured tobacco cultivation to enhance the tobacco plants' resistance to diseases and pests and improve the quality of tobacco leaves.

[0018] Compared with existing technologies, the beneficial effects of this invention are as follows: This method, through the application of a specific combination of biochar and biological control agents, not only effectively improves the physical and chemical properties of tobacco field soil and promotes the growth and development of flue-cured tobacco plants, but also significantly enhances the disease resistance of the tobacco plants themselves. In field application, this control measure shows excellent control effects against tobacco black shank and bacterial wilt. Specifically, at the initial stage of black shank, the control effect of this technology can reach 85.32%, and even at the peak of black shank occurrence, the control effect can still be stably maintained at 84.77%, showing strong persistence and field adaptability. At the same time, the control effect against tobacco bacterial wilt also exceeds 90%, which is significantly better than conventional chemical treatment, fully verifying the practical value and promotion potential of this method in the integrated management of major soil-borne diseases of tobacco. Attached Figure Description

[0019] Figure 1 This is a diagram illustrating the steps of the method of the present invention;

[0020] Figure 2 This is a photograph of the actual planted mint and tobacco plants of this invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0022] Please see Figures 1-2 This invention provides a technical solution: a method for preventing and controlling tobacco black shank disease and bacterial wilt, comprising the following steps:

[0023] S1: Applying biochar improves soil permeability

[0024] Before transplanting tobacco seedlings, mix biochar with a special compound fertilizer for flue-cured tobacco in a ratio of 1:0.5 to 1:1, and apply the mixture to the soil. This step improves soil permeability, fosters a well-developed root system in the tobacco plants, and enhances their resistance to adverse conditions. Biochar, as a harmless carbon source produced by the high-temperature carbonization of organic matter, has strong adsorption, water retention, and fertilizer retention capabilities, thereby effectively improving soil quality and promoting healthy plant growth.

[0025] S2: Use a combination of biological agents and pesticides to increase the number of beneficial soil bacteria.

[0026] Three days after transplanting tobacco seedlings, apply a root drench with a mixture of mineral-derived potassium humate, Bacillus subtilis, and Trichoderma harzianum. This combination of biological agents effectively inhibits the growth of pathogens and promotes the proliferation of beneficial soil microorganisms. Bacillus subtilis inhibits the growth of various pathogens, while Trichoderma harzianum helps decompose organic matter in the soil. Use 1000 ml of the solution per plant for the root drench, applying three times consecutively, with a 15-day interval between each application, to enhance the control effect.

[0027] S3: Intercropping mint optimizes soil ecology

[0028] Within one week of transplanting tobacco seedlings, select healthy, disease-free mint plants as mother plants. Cut the mint runners into several sections, each containing at least one node, and bury them in the soil. Plant the mint between every two tobacco seedlings, with a spacing of 15 cm. Bury the nodes of the mint runners 3-5 cm deep, with the stems and leaves above the soil surface. Plant 2-3 sections of mint runners per section. The root system and aroma components of mint can effectively optimize soil ecology, inhibit the growth of pathogens, and improve soil microbial diversity, thereby enhancing the tobacco's resistance to black shank and bacterial wilt.

[0029] Example 1: Application of biochar and compound fertilizer, root irrigation with bio-inoculants, and intercropping of mint.

[0030] Objective: To improve the disease resistance of tobacco plants and prevent tobacco black shank and bacterial wilt.

[0031] 1. Applying biochar improves soil permeability

[0032] Before transplanting tobacco seedlings, mix biochar and flue-cured tobacco-specific compound fertilizer in a 1:1 ratio and apply the mixture to the soil at a depth of approximately 10-15 cm. This process improves soil permeability, enhances root development, and increases the tobacco plant's ability to adapt to adverse conditions.

[0033] 2. Use of biological agents in combination with other medications

[0034] On the third day after transplanting tobacco seedlings, apply a mixture of mineral-derived potassium humate, Bacillus subtilis, and Trichoderma harzianum for root drenching. Use 1000 ml per seedling, keeping the soil moist after drenching to ensure the pesticide penetrates the soil. Repeat this treatment three times, with a 15-day interval between each application. During this period, this method effectively increases the number of beneficial microorganisms in the soil, inhibits the growth of pathogens, and optimizes the soil's microecological environment.

[0035] 3. Intercropping mint optimizes soil ecology

[0036] One week after transplanting tobacco seedlings, select healthy, disease-free mint plants and cut runners, inserting them between every two seedlings. Bury the runners 3-5 cm deep in the soil, ensuring a 15 cm spacing between each seedling. Use 2-3 runners for every two seedlings. The roots and aroma components of mint effectively optimize soil ecology and inhibit soil pathogens.

[0037] result:

[0038] Data after 30 days showed that the tobacco plants in the treatment group had significantly better plant height (25.07 cm), stem circumference (1.88 cm), number of leaves (12.00), and leaf area index (0.62) than the control group.

[0039] Disease control efficacy: During the peak growing season on June 17, the control efficacy of black shank disease in the treatment group reached 85.32%, and the control efficacy of bacterial wilt reached 93.50%, which were significantly improved compared with the control group.

[0040] Example 2: Enhance the application of biological agents, combined with peppermint intercropping

[0041] Objective: To control tobacco black shank and bacterial wilt by combining pesticide application and intercropping, and to optimize the growing environment.

[0042] 1. Apply a mixture of biochar and compound fertilizer

[0043] The application method is the same as in Example 1. Biochar and flue-cured tobacco-specific compound fertilizer are mixed at a ratio of 1:0.5 and applied to the tobacco planting soil. The use of biochar can improve the soil's water retention and aeration, while also promoting the growth of tobacco roots.

[0044] 2. Use biological agents in combination with pesticides for root irrigation

[0045] Three days after transplanting tobacco seedlings, prepare a mixture of potassium humate, Bacillus subtilis, and Trichoderma harzianum for root drenching. Use 1000 ml per plant, applying three times consecutively, with a 15-day interval between applications. This method effectively increases beneficial bacteria in the soil and enhances its disease resistance.

[0046] 3. Intercropping techniques for mint

[0047] In the first week after transplanting tobacco seedlings, select healthy and disease-free mint plants, cut runners, and plant them between every two seedlings. Plant 2-3 mint runners between each seedling, ensuring a planting depth of 3-5 cm, to ensure that the growth of the mint roots and tobacco plants complement each other.

[0048] result:

[0049] Data after 60 days showed that the tobacco plants in the treatment group were superior to those in the control group in terms of plant height (106.58 cm), stem circumference (2.50 cm), number of leaves (22.22), leaf length (56.12 cm), leaf width (21.54 cm), and leaf area index (2.84).

[0050] Table 1 Effects of treatments on tobacco plant growth and development

[0051]

[0052] Disease control efficacy: At the initial outbreak stage on July 2nd, the control efficacy against black shank was 84.77%, and against bacterial wilt was 91.34%. This biological treatment combined with intercropping significantly reduced the disease incidence and effectively controlled the spread of the disease.

[0053] Table 2. Control effects of treatments on tobacco black shank disease

[0054]

[0055] Table 3. Control effect of treatments on tobacco bacterial wilt

[0056]

[0057]

[0058] These two examples combine multiple methods, including biochar, compound fertilizer, high-quality biological agents, and intercropping with mint, to effectively control black shank and bacterial wilt in tobacco, and promote the growth and development of tobacco. This method not only improves the crop's resistance to adverse conditions but also optimizes the soil micro-ecological environment, providing a strong guarantee for high yield and healthy growth of tobacco.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for controlling tobacco black shank and bacterial wilt, characterized by, The method comprises the following steps: S1, applying biochar to improve soil permeability: before transplanting tobacco seedlings, mix biochar with special compound fertilizer for flue-cured tobacco in proportion, apply it into the soil after mixing evenly, improve the permeability of the soil, cultivate the root system of tobacco plants, and enhance the stress resistance of tobacco plants; S2, using bio-bacterium combined medication to increase the number of soil beneficial bacteria: 3 days after transplanting tobacco seedlings, use a mixed preparation of mineral potassium fulvic acid, bacillus subtilis and trichoderma harzianum for root irrigation; S3, interplanting peppermint to optimize soil ecology: within one week after transplanting tobacco seedlings, select healthy and disease-free peppermint plants as mother plants, cut the creeping stems into several segments, each containing at least one node, and bury them in the soil, with a planting position of between every two tobacco seedlings.

2. The method for controlling tobacco black shank and bacterial wilt according to claim 1, wherein, The proportion of biochar to special compound fertilizer for flue-cured tobacco in S1 is 1:0.5-1:

1.

3. The method for controlling black root rot and bacterial wilt according to claim 2, wherein The biochar is a harmless carbon source formed by high-temperature carbonization of organic matter, with strong adsorption and water and fertilizer retention properties.

4. The method for controlling black root rot and bacterial wilt according to claim 1, wherein, The root irrigation liquid in S2 is used at a dosage of 1000 ml per plant, continuously for 3 times, with an interval of 15 days each time.

5. The method for controlling black root rot and bacterial wilt according to claim 1, wherein, The bio-bacterium includes a combination of potassium fulvic acid, bacillus subtilis and trichoderma harzianum, the bacillus subtilis is used to inhibit the growth of pathogenic bacteria, and the trichoderma harzianum is used to decompose organic matter in the soil and promote the proliferation of soil beneficial bacteria.

6. The method for controlling black root rot and bacterial wilt according to claim 1, wherein, The plant spacing in S3 is 15 cm, and 2-3 portions of peppermint creeping stems are planted between every two tobacco seedlings.

7. The method for controlling black root rot and bacterial wilt according to claim 6, wherein the composition is applied to the soil or the plant. The planting node of the peppermint creeping stem is buried in the soil at a depth of 3-5 cm, with the stems and leaves on the node exposed to the soil surface.

8. The method for controlling black root rot and bacterial wilt according to claim 1, wherein, The method is applied to each stage of flue-cured tobacco cultivation to enhance the disease and pest resistance of tobacco plants and improve the quality of tobacco leaves.

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