A flue-cured tobacco rhizome disease prevention and control method based on soil monitoring regulation

Abstract

The application discloses a flue-cured tobacco rhizome disease prevention and control method based on soil monitoring and regulation, and relates to the technical field of environmental regulation, which comprises the following steps: acquiring the environmental physical parameters of the rhizosphere soil of flue-cured tobacco in real time, and inputting the weather forecast information of a target tobacco area; calculating a rhizome disease infection potential index according to the environmental physical parameters and the weather forecast information; comparing the rhizome disease infection potential index with preset low-risk and high-risk threshold values, and executing a hierarchical prevention and control decision according to the comparison result; the hierarchical prevention and control decision at least comprises one or a combination of multiple kinds of agricultural prevention and control measures, biological prevention and control measures and precise pesticide prevention and control measures; the application aims to realize early warning by constructing the rhizome disease infection potential index, quantifying the feedforward stress of the rhizosphere micro-ecology and the weather, and realizing the adaptive triggering and cooperative execution of the agricultural, biological and pesticide three-level prevention and control measures.

Description

Technical Field

[0001] This invention relates to the field of environmental control technology, and in particular to a method for controlling root and stem diseases of flue-cured tobacco based on soil monitoring and control. Background Technology

[0002] In tobacco-growing areas where high temperature and humidity are common and the rainy season is concentrated, root and stem soil-borne diseases such as black shank, bacterial wilt and root rot of flue-cured tobacco are serious and have become obstacles to high-quality and stable tobacco production. The above pathogens reproduce exponentially in the hot and humid rhizosphere environment. After infecting the vascular bundle tissue of the root and stem of tobacco plants, they cause obstruction of water and nutrient transport, resulting in missing seedlings, premature aging and even crop failure. Currently, the control of the above-mentioned diseases mainly relies on root irrigation with chemical agents. However, long-term single or repeated application of chemical agents has led to the increasing resistance of pathogens year by year, resulting in a continuous decline in control efficacy. This forces the concentration of agents to be continuously increased, creating a vicious cycle of escalating dosage and intensified resistance. At the same time, the broad-spectrum killing effect of chemical agents, while inhibiting pathogens, also severely damages the beneficial microbial community in the rhizosphere, weakening the soil's natural disease suppression capacity and further exacerbating continuous cropping obstacles. Among the existing methods, there are also attempts to use agricultural agronomic measures or biological agents for control. However, these measures are mostly simple superpositions of single methods, lacking a coordinated decision-making mechanism between the measures. The timing of implementation relies solely on manual experience and judgment, often missing the optimal intervention window and making it difficult to achieve a sustained and stable control effect. Therefore, there is an urgent need in this field for a comprehensive regulation method for flue-cured tobacco root and stem diseases that can comprehensively quantify rhizosphere temperature and humidity, redox characteristics, and meteorological feedforward stress, and thereby achieve graded, precise, and green prevention and control, in order to solve the above problems. Summary of the Invention

[0003] This invention aims to provide early warning by constructing a root and stem disease infection potential index, quantify feedforward stress from rhizosphere microecology and meteorology, and achieve adaptive triggering and coordinated execution of three-level control measures involving agriculture, biology, and chemicals.

[0004] To achieve the above objectives, this invention provides a method for controlling root and stem diseases of flue-cured tobacco based on soil monitoring and regulation, comprising the following steps: Step 1: Obtain real-time environmental physical parameters of the rhizosphere soil of flue-cured tobacco and connect them to the meteorological forecast information of the target tobacco area; Step 2: Calculate the root and stem disease infection potential index based on the environmental physical parameters and the meteorological forecast information; Step 3: Compare the root and stem disease infection potential index with preset low-risk and high-risk thresholds, and implement graded prevention and control decisions based on the comparison results; The tiered prevention and control decision-making includes at least one or a combination of agricultural control measures, biological control measures, and precision pesticide control measures.

[0005] Preferably, in step one, the environmental physical parameters are collected in real time by wireless sensor nodes distributed and deployed in the root layer of the tobacco field ridges, specifically including: rhizosphere weighted average soil temperature. Rhizosphere weighted average soil volumetric water content Rhizosphere weighted average soil redox potential Rhizosphere weighted average soil pH and the daily range of soil temperature ; The weather forecast information includes the cumulative predicted rainfall for the next 72 hours. and the average relative humidity of the air in the next 72 hours .

[0006] Preferably, in step two, the calculation model for the root and stem disease infection potential index is based on meteorological feedforward factors. Thermal fluctuation sensitizer and the fundamental potential of the rhizosphere microecology The product of the three is expressed as follows:

[0007] In the formula, The disease susceptibility index is a value that is directly proportional to the probability of the rhizome being infected by the disease.

[0008] Preferably, the meteorological feedforward factor Calculated using the following model:

[0009] in, The rainfall amount is the reference amount for flooding in the target tobacco-growing area. This is the threshold for sensitivity to air humidity.

[0010] Preferably, the thermal fluctuation sensitization factor Calculated using the following model:

[0011] in, This serves as a reference for the diurnal range of the average annual soil temperature in the target tobacco-growing area. It is a hyperbolic cosine function.

[0012] Preferably, the rhizosphere microecological foundation potential Calculated using the following model:

[0013] in, The optimal reference temperature for tobacco root system For the target tobacco-growing area, the reference field water holding capacity is... This is the critical reference potential for aerobic-anaerobic rhizosphere. The optimal pH level for the development of tobacco root and stem diseases. The rhizosphere weighted average soil pH The tolerance scale constant.

[0014] Preferably, in step three, the process of implementing tiered prevention and control decisions based on the comparison results includes: when If the risk level is determined to be low, only the aforementioned agricultural prevention and control measures will be implemented. when When the risk level is determined to be medium, both the agricultural control measures and the biological control measures shall be implemented. when When the risk level is determined to be high, the aforementioned agricultural control measures, biological control measures, and precision pesticide control measures shall be implemented simultaneously. in, The threshold for low-risk classification This is the threshold for high-risk classification.

[0015] Preferably, the agricultural control measures include: implementing single-row cultivation on raised ridges, with the ridge height set at 30cm to 35cm; deep plowing and sun-drying after ridging, with the sun-drying time set at 10 to 15 days; and timely removal of diseased and damaged tobacco plants in the tobacco field.

[0016] Preferably, the biological control measures include: dipping roots with a biochar-loaded Bacillus agent during the tobacco transplanting period; and drenching roots once with a biochar-loaded Bacillus agent during the tobacco clump stage; wherein the effective viable count of the Bacillus agent is not less than 1 billion CFU / g, and the dosage of the root drenching treatment is 2 kg to 3 kg per acre.

[0017] Preferably, the precise pesticide control measures include: unlocking the chemical drenching permission only when the risk level is determined to be high, and using low-toxicity biological fungicides for alternating precise application; the interval between two consecutive applications is 7 to 10 days, and the number of consecutive applications is 2 to 3; and when the root and stem disease infection potential index... The value fell back to the high-risk classification threshold twice in a row. If the following occurs, immediately disable the chemical drenching function and stop chemical intervention.

[0018] Compared with existing designs, the present invention has the following advantages: This invention introduces meteorological feedforward factors, incorporating the cumulative rainfall and relative humidity of the next 72 hours into the calculation of the root and stem disease infection potential index. This allows for the automatic triggering of agronomic interventions before the actual arrival of high-humidity, rainy weather, overcoming the lag in traditional control methods that only allow for symptomatic application of pesticides. It shifts the control point forward to before disease infection. Furthermore, agricultural control, biological control, and precision chemical control are all triggered uniformly by the root and stem disease infection potential index and complement each other, forming a continuous and stable three-dimensional control system. Attached Figure Description

[0019] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0020] Figure 1 This is a flowchart illustrating the method for controlling root and stem diseases in flue-cured tobacco provided in this embodiment. 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] Example 1: This example is applied to a typical hot and humid tobacco-growing region. These regions generally have high average annual temperatures and humidity, and concentrated rainfall during the tobacco growing season. Tobacco cultivation typically involves five stages: seedling stage, transplanting stage, seedling stage, vigorous growth stage, and maturity / harvest stage. The period from transplanting to vigorous growth is the peak period for the infection and symptoms of root and stem diseases in tobacco (including black shank, bacterial wilt, and root rot). During this period, the high temperature and humidity in the rhizosphere environment, combined with the soil microecological imbalance caused by continuous cropping, leads to an exponential increase in pathogen reproduction rates. Roots and stems are easily infected and blocked, causing wilting, death, and even large-scale crop failure. Therefore, this example provides a method for controlling root and stem diseases in tobacco based on soil monitoring and regulation. Please refer to [link to relevant documentation]. Figure 1 This includes the following steps: S1, real-time acquisition of environmental physical parameters of the rhizosphere soil of flue-cured tobacco, and access to meteorological forecast information of the target tobacco area; Specifically, environmental physical parameters are collected in real time by wireless sensor nodes distributed in the root layer of the tobacco field ridges. The sensor nodes are deployed as follows: multiple representative sampling points are selected in the target tobacco field along an "S" shaped route. The number of representative sampling points is adjusted based on the area of ​​the tobacco field. At each sampling point, a sensor probe is buried 10cm away from the base of the tobacco plant stem on both sides of the ridge. The sampling depth is 15cm (main root layer) and 25cm (lateral root layer). Each sensor continuously collects data at a sampling frequency of 3 hours / time. The real-time data of each node is transmitted to the field data aggregation gateway via wireless communication. The gateway performs an arithmetic average of the data of the same layer of different nodes at the same time, and then calculates the rhizosphere weighted average according to the depth weight (0.6 for 15cm layer and 0.4 for 25cm layer) as the representative value of the overall rhizosphere environment of the tobacco field at that time. Environmental physical parameters include: rhizosphere weighted average soil temperature Rhizosphere weighted average soil volumetric water content Rhizosphere weighted average soil redox potential Rhizosphere weighted average soil pH and the daily range of soil temperature ; It should be noted that, regarding soil temperature, temperature directly affects the growth and reproduction rate of pathogens and the metabolic activity of tobacco roots. Within a suitable temperature range, the rate of biochemical reactions accelerates exponentially with increasing temperature. Regarding soil volumetric water content, water is an essential medium for the diffusion and infection of pathogen zoospores. When the soil water content is close to the field capacity, the continuous water film in the soil pores provides a channel for the chemotactic movement of Phytophthora zoospores. The higher the water saturation, the greater the probability of pathogens coming into contact with the root surface. Soil redox potential is a direct indicator of soil aeration and reducing power. When the potential is below a critical value, the soil is in a strongly reducing state, anaerobic pathogens (especially *Ralstonia solanacearum*) proliferate rapidly, and reducing toxic substances (such as Fe) are also released. 2+ Mn 2+ Accumulation of H2S damages root epidermal cells, creating wound channels for pathogen invasion. Regarding soil pH, its value determines the composition of the rhizosphere microbial community and the dynamics of pathogens. Soil acidification in tobacco-growing areas inhibits the activity of beneficial actinomycetes and Bacillus, while Ralstonia solanacearum and Fusarium wilt thrive under slightly acidic to neutral conditions. As for the diurnal temperature range, drastic fluctuations in temperature between day and night exacerbate lipid peroxidation in root cell membranes, increase energy consumption for cell osmotic regulation, reduce the inherent resistance of the root system, and make it easier for pathogens to break through the physical barrier of the root surface.

[0023] Specifically, the weather forecast information includes the cumulative predicted rainfall for the next 72 hours. and the average relative humidity of the air in the next 72 hours Weather forecast information is accessed through the communication module of the IoT gateway to the 72-hour forecast data released by the meteorological department in the target area.

[0024] It should be noted that rainfall and high humidity dominated the outbreak of rhizomes and stems. The cumulative rainfall in the next 72 hours directly determines the increase and duration of soil moisture content, while relative humidity affects the stomatal opening of leaves, thereby indirectly regulating the rhizosphere water balance and the spread efficiency of pathogens. Incorporating these two meteorological feedforward parameters into the risk index model enables this embodiment to have predictive control capabilities, initiating intervention measures before severe weather arrives, rather than passively applying pesticides after the disease symptoms appear following rainfall.

[0025] S2, calculate the root and stem disease infection potential index based on environmental physical parameters and meteorological forecast information; Specifically, after receiving the real-time and forecast data acquired in step S1, the data aggregation gateway substitutes this data into the pre-set core algorithm model in the edge computing module to calculate the infection trend of root and stem diseases in tobacco fields within the next 72 hours, i.e., the root and stem disease infection potential index. The calculation model for this root and stem disease infection potential index is based on meteorological feedforward factors. Thermal fluctuation sensitizer and the fundamental potential of the rhizosphere microecology The product of the three is expressed as follows: ; Among them, meteorological feedforward factors The expression is:

[0026] In the formula, The cumulative rainfall forecast for the next 72 hours is obtained directly from weather forecasts. This is a preset reference rainfall amount for flooding in the target tobacco area. This value is set based on the median rainfall amount that caused the topsoil moisture content to reach saturation in a single rainfall event from the historical meteorological statistics of the target tobacco area. It is a fixed reference constant that can be predetermined based on the climate characteristics of the tobacco area. The average relative humidity of the air for the next 72 hours is obtained directly from the weather forecast and normalized to a decimal in the range of 0 to 1. The preset physiological sensitivity threshold for air humidity is also a decimal in the range of 0 to 1, representing the critical point at which the transmission efficiency of pathogens begins to increase significantly when the air humidity exceeds this value. This value is determined by the lower limit of the annual average relative humidity during the growing season of flue-cured tobacco in the target tobacco area. To maximize the function, ensure that the humidity term does not have a negative value; This meteorological feedforward factor The stress of future weather conditions is quantified in a feedforward manner, when the predicted humidity is not higher than the sensitivity threshold. At that time, the excess humidity was truncated to 0. =1 indicates that dry climates do not produce additional feedforward stress amplification effects; when humidity exceeds the threshold, the precipitation term... Multiplying the excess humidity term by the saturation growth curve (where the ratio asymptotically approaches 1 from 0 as rainfall increases) makes... Under extreme rain and high humidity conditions, the maximum value approaches 2, thus giving this embodiment the ability to be directly deployed in different ecological tobacco areas.

[0027] Among them, thermal fluctuation sensitization factor The expression is:

[0028] In the formula, The daily soil temperature range is calculated from the difference between the highest and lowest soil temperatures of the day. The reference value for the annual average daily soil temperature range of the target tobacco area is determined by the multi-year average of the daily soil temperature range during the flue-cured tobacco growing season in the historical meteorological data of the target tobacco area. Let be a hyperbolic cosine function, and its expansion is: ; This embodiment introduces the hyperbolic cosine function into the construction of the temperature difference sensitization factor. When =0 (no temperature difference), =1, thermal fluctuation sensitization factor It doesn't work at all, when Compared to As the temperature fluctuation sensitization factor gradually increases, The accelerated rise in a superlinear manner reflects the law that the root system's resistance deteriorates rapidly with increasing temperature difference.

[0029] Among them, the basic potential of the rhizosphere microecology The expression is:

[0030] In the formula, Rhizosphere weighted average soil temperature; The preset optimal reference temperature for enzyme activity in flue-cured tobacco roots is directly set based on the optimal temperature for root growth of this flue-cured tobacco variety, and is a fixed parameter based on variety characteristics. This represents the rhizosphere weighted average soil volumetric water content. The reference field water holding capacity for the target tobacco field is determined by consulting a soil physics handbook based on the soil texture of the target tobacco field. The preset rhizosphere aerobic-anaerobic critical reference potential is the threshold potential for the reducing dissolution of iron and manganese oxide systems in this type of soil. It is directly determined by soil chemistry principles and generally ranges from 200 to 300 mV. Rhizosphere weighted average soil redox potential; The rhizosphere weighted average soil pH; The optimal pH range for the development of tobacco root and stem diseases is set based on the optimal pH range for the development of major root and stem diseases such as black shank and bacterial wilt in tobacco pathology. The preset pH tolerance scale constant describes the spread of disease risk as pH deviates from the optimum value. It can be determined through fitting experiments and is usually taken as 0.7. In the formula, the first term This reflects the positive nonlinear correlation between pathogen reproduction rate and temperature, and the trend is amplified by a quadratic power; the second term... The rate of pathogen spread is directly proportional to the gradient of moisture content; when the moisture content approaches field capacity... At this time, the migration efficiency of pathogens exhibits a non-linear surge, and this surge trend is also increased by quadratic power; the third term In the middle, when At higher levels (good ventilation, strong oxidizing properties), the ratio is less than 1, and its contribution to the fundamental potential decreases. When the ratio decreases due to waterlogging or anaerobic decomposition of organic matter, it increases inversely, amplifying the disease infection potential and thus reflecting the trend that the stronger the reducing potential, the higher the risk of proliferation of anaerobic soil-borne pathogens; Item 4 In this case, when the rhizosphere pH is exactly equal to the optimal value for disease development... When the pH is 1, no decay is applied to the basic potential. As the pH deviates towards acidity or alkalinity, the decay term decreases smoothly in an exponential manner with squared distance, thus simulating the process by which the activity of pathogens is gradually impaired as the pH deviates from the optimal value.

[0031] Ultimately, meteorological feedforward factors This reflects the accelerated effect of rainfall and high humidity in the next 72 hours on the spread and infection efficiency of pathogens, enabling the system to provide early warning capabilities; thermal fluctuation sensitization factor This study reflects the nonlinear quantification of the weakening effect of diurnal temperature variation on the stress resistance of flue-cured tobacco roots, and quantitatively incorporates the physiological stress state of plants into risk assessment; the basic potential of the rhizosphere microecology. It reflects the basic risk level of pathogen reproduction and infection determined by the current rhizosphere temperature and humidity, redox characteristics and pH; the product of the three factors reflects the overall risk potential of flue-cured tobacco rhizomes to be infected by soil-borne pathogens during the next 72-hour window, under the combined effect of the three factors: the rhizosphere ecological environment, the plant's own stress resistance and the upcoming meteorological stress.

[0032] S3, the edge computing module in the data aggregation gateway completes... After real-time calculation, the root and stem disease infection potential index is compared with the preset low-risk and high-risk thresholds, and a graded prevention and control decision is made based on the comparison results. Among them, the tiered prevention and control decision-making includes at least one or a combination of agricultural control measures, biological control measures, and precision pesticide control measures.

[0033] Specifically, the process of implementing tiered prevention and control decisions based on comparison results includes: when When the risk level is determined to be low, it indicates that the current rhizosphere ecological environment is good, future meteorological conditions will not pose a significant stress, and the probability of natural occurrence of rhizosphere diseases is low. Therefore, only agricultural control measures are implemented, and the health of the field microenvironment is maintained through conventional agronomic methods. when When the risk level is determined to be medium, it indicates that several stress factors have appeared in the rhizosphere environment (such as high soil moisture, decreased potential, pH shift, or forecasted rainfall). The risk of pathogen infection is accumulating but has not yet reached the critical point of outbreak. Therefore, it is necessary to implement agricultural control measures and biological control measures at the same time, that is, to improve the environment through agronomic means while introducing beneficial microorganisms to establish a biological barrier in the rhizosphere. when When the risk level is determined to be high, it indicates that the root zone temperature and humidity are too high, the redox state is extremely deteriorated, and heavy rainfall and high humidity are coming. The combination of these three factors makes the root and stem diseases critical to break out. Therefore, it is necessary to implement agricultural control measures, biological control measures, and precise chemical control measures at the same time. in, The threshold for low-risk classification The high-risk classification thresholds are all assigned based on experience.

[0034] In one specific implementation, agricultural control measures include: implementing single-row cultivation on raised ridges, with the ridge height set at 30cm to 35cm; deep plowing and sun-drying the soil after ridging, with the sun-drying time set at 10 to 15 days; and timely removal of diseased and damaged tobacco plants from the tobacco field.

[0035] It should be noted that the so-called high-ridge single-row cultivation refers to raising the soil in the field to form a single-row planting ridge, with the ridge height of 30-35cm, and planting tobacco seedlings in the center of the ridge top. This measure allows excess water to drain quickly along the sides of the ridge during rainfall, avoiding water accumulation around the roots. The soil temperature drops, while the raised beds increase the surface area of ​​the root zone that receives solar radiation, which is beneficial for increasing soil temperature and promoting growth. Recovery; Deep plowing and sun-drying refers to turning over and breaking up the topsoil (depth ≥ 30cm) before ridging and exposing it to the sun for 10-15 days. This uses ultraviolet light to kill pathogen spores and insect eggs remaining in the topsoil, while promoting the full oxidation and decomposition of organic matter in the soil and eliminating the reducing toxic substances accumulated from continuous cropping; Timely removal of diseased plant debris refers to taking the diseased plant stems, leaves and root debris left over from the previous season out of the field for harmless treatment.

[0036] In one specific implementation, the biological control measures include: dipping roots with biochar-loaded Bacillus spores during the tobacco transplanting period; and drenching roots once with the same type of biochar-loaded Bacillus spores during the tobacco clump stage; the effective viable count of the Bacillus spores inoculum is not less than 1 billion CFU / g, and the dosage for root drenching is 2 kg to 3 kg per acre.

[0037] It should be noted that the so-called biochar-borne Bacillus inoculant refers to a composite inoculant (commercially available product) prepared by adsorbing highly active biocontrol strains such as Bacillus subtilis or Bacillus amyloliquefaciens onto a porous biochar carrier. The biochar carrier itself has abundant microporous structure and cation exchange capacity, providing an ideal colonization microenvironment for beneficial bacteria, while also playing a synergistic role in improving acidified soil and adsorbing rhizosphere toxins. The so-called root-dipping treatment refers to completely immersing the roots of tobacco seedlings in a diluted suspension of the inoculant (diluted 50 times) during transplanting, ensuring that the inoculant fully adheres to the root surface and its micro-wounds, guaranteeing... Beneficial bacteria establish a dominant position in the rhizosphere during the critical early stages after transplanting. The so-called root irrigation treatment refers to preparing the inoculum into a suspension and then directionally irrigating it around the base of the tobacco plant stem into the rhizosphere area, allowing the inoculum to directly contact the root surface and penetrate deep into the root soil, replenishing and consolidating the population density of beneficial bacteria that have colonized the roots during the transplanting period. This biological control measure can achieve green control by "using bacteria to control bacteria" through mechanisms such as competitive exclusion of beneficial bacteria, secretion of antimicrobial substances, and induction of systemic resistance in plants. However, compared with precision chemical control measures, the advantages of biological control are strong prevention, environmental friendliness, and no development of drug resistance problems, and its action speed is relatively mild.

[0038] In one specific implementation, the precision pesticide control measures include: unlocking the permission for chemical pesticide root irrigation only when the risk level is determined to be high, and using low-toxicity biological fungicides for alternating precision pesticide application; the interval between two consecutive pesticide applications is 7 to 10 days, and the number of consecutive pesticide applications is 2 to 3; The so-called low-toxicity biological fungicides include, but are not limited to, streptomycin, ningnanmycin, and metalaxyl-cymoxanil, etc., and are not specifically limited in this embodiment; when The real-time calculated value is lower than At that time, regardless of whether sporadic disease symptoms appear in the field, the system refuses to unlock the permission for chemical pesticide root irrigation, and forces the use of agricultural and biological control methods for intervention; only when The calculated value reaches or exceeds Only when this mathematical threshold is reached is the permission for chemical root irrigation unlocked. This mechanism eliminates the reliance on traditional prevention and control methods, such as indiscriminate irrigation upon diagnosis and excessive dosage, from the source of decision-making.

[0039] Furthermore, when The value dropped to [value] for two consecutive monitoring periods. If the following occurs, immediately stop the use of chemical agents for root irrigation and cease chemical intervention. Even if the planned 2-3 treatment courses of chemical agents have not yet been completed, the subsequent application of the agent should be forcibly interrupted to ensure that the amount of chemical agents used is strongly correlated with the actual dynamic risk. This will prevent pesticide waste and residue risks caused by continuing to use the agent after the risk has subsided, which would result in fixed application times.

[0040] The method for controlling flue-cured tobacco root and stem diseases based on soil monitoring and regulation provided in this embodiment uses distributed sensors to perceive the rhizosphere microenvironment and root and stem disease infection potential index in real time. Quantify future risks in advance, and based on The implementation of a tiered prevention and control strategy that combines environmental improvement, biological barriers, and chemical suppression fundamentally solves the problems of symptom-based treatment and reactive, lagging approaches in existing technologies. This enables continuous, green, efficient, and precise control of pathogens such as black shank, bacterial wilt, and root rot in flue-cured tobacco in hot and humid tobacco-growing areas.

[0041] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for controlling root and stem diseases of flue-cured tobacco based on soil monitoring and regulation, characterized in that, Includes the following steps: Step 1: Obtain real-time environmental physical parameters of the rhizosphere soil of flue-cured tobacco and connect them to the meteorological forecast information of the target tobacco area; Step 2: Calculate the root and stem disease infection potential index based on the environmental physical parameters and the meteorological forecast information; Step 3: Compare the root and stem disease infection potential index with preset low-risk and high-risk thresholds, and implement graded prevention and control decisions based on the comparison results; The tiered prevention and control decision-making includes at least one or a combination of agricultural control measures, biological control measures, and precision pesticide control measures.

2. The method according to claim 1, characterized in that, In step one, the environmental physical parameters are collected in real time by wireless sensor nodes distributed and deployed in the root layer of the tobacco field ridges, specifically including: rhizosphere weighted average soil temperature. Rhizosphere weighted average soil volumetric water content Rhizosphere weighted average soil redox potential Rhizosphere weighted average soil pH and the daily range of soil temperature ; The weather forecast information includes the cumulative predicted rainfall for the next 72 hours. and the average relative humidity of the air in the next 72 hours .

3. The method according to claim 2, characterized in that, In step two, the calculation model for the root and stem disease infection potential index is based on meteorological feedforward factors. Thermal fluctuation sensitizer and the fundamental potential of the rhizosphere microecology The product of the three is expressed as follows: In the formula, The disease susceptibility index is the root and stem disease susceptibility index, and its value is directly proportional to the probability of root and stem infection by disease.

4. The method according to claim 3, characterized in that, The meteorological feedforward factor Calculated using the following model: in, The rainfall amount is the reference amount for flooding in the target tobacco-growing area. This is the threshold for sensitivity to air humidity.

5. The method according to claim 3, characterized in that, The thermal fluctuation sensitizer Calculated using the following model: in, This serves as a reference for the diurnal variation of the average annual soil temperature in the target tobacco-growing area. It is a hyperbolic cosine function.

6. The method according to claim 3, characterized in that, The fundamental potential of the rhizosphere microecology Calculated using the following model: in, The optimal reference temperature for tobacco root system For the target tobacco-growing area, the reference field water holding capacity is... This is the critical reference potential for aerobic-anaerobic rhizosphere. The optimal pH level for the development of tobacco root and stem diseases. The rhizosphere weighted average soil pH The tolerance scale constant.

7. The method according to claim 3, characterized in that, In step three, the process of implementing tiered prevention and control decisions based on the comparison results includes: when If the risk level is determined to be low, only the aforementioned agricultural prevention and control measures will be implemented. when When the risk level is determined to be medium, both the agricultural control measures and the biological control measures shall be implemented. when When the risk level is determined to be high, the aforementioned agricultural control measures, biological control measures, and precision pesticide control measures shall be implemented simultaneously. in, The threshold for low-risk classification This is the threshold for high-risk classification.

8. The method according to claim 7, characterized in that, The agricultural control measures include: implementing single-row cultivation on raised ridges, with the ridge height set at 30cm to 35cm; deep plowing and sun-drying the soil after ridging, with the sun-drying time set at 10 to 15 days; and timely removal of diseased and damaged tobacco plants from the tobacco field.

9. The method according to claim 7, characterized in that, The biological control measures include: dipping roots with biochar-loaded Bacillus spores during the tobacco transplanting period; and drenching roots once with the same type of biochar-loaded Bacillus spores during the tobacco clump stage; the effective viable count of the Bacillus spores in the inoculum is not less than 1 billion CFU / g, and the dosage of the drenching treatment is 2 kg to 3 kg per mu.

10. The method according to claim 7, characterized in that, The precise pesticide control measures include: unlocking the permission for chemical root irrigation only when the risk level is determined to be high, and using low-toxicity biological fungicides for alternating precise application; the interval between two consecutive applications is 7 to 10 days, and the number of consecutive applications is 2 to 3; and when the root and stem disease infection potential index... The value fell back to the high-risk classification threshold twice in a row. If the following occurs, immediately disable the chemical drenching function and stop chemical intervention.

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