Biological control method for wheat and corn sheath blight

Abstract

The invention provides a biological control method for wheat and corn sheath blight, and belongs to the technical field of crop control. The biological control method comprises the following steps: applying a broad-spectrum continuous cropping-resistant microecological preparation before wheat or corn is sown; after the wheat turns green or the three-leaf stage of the corn, a broad-spectrum Lvkangwei microbial agent is sprayed. According to the micro-ecological regulation and control principle, two microbial preparations are combined, and the application mode, the application period and the application amount are further adjusted, so that the occurrence of wheat and corn sheath blight can be effectively controlled, the use of chemical pesticides in the agricultural production process can be reduced, the chemical pesticide residues are reduced, the quality of wheat and corn is improved, and the soil is improved; farmland non-point source pollution is reduced, and a biological control technical support is provided for green prevention and control of diseases and insect pests and green transformation development of agriculture.

Description

Technical Field

[0001] This invention belongs to the field of crop disease control technology, and in particular relates to a biological control method for wheat and corn sheath blight. Background Technology

[0002] Wheat and corn, as major food crops, are highly susceptible to sheath blight during cultivation, which has become one of the major obstacles to high yield and quality of wheat and corn. Sheath blight, a soil-borne disease caused by pathogens such as Rhizoctonia solani, is characterized by its wide range of incidence, multiple transmission routes, and severe damage. The pathogen mainly overwinters as sclerotia or mycelium in the soil and on diseased plant debris. Under suitable temperature and humidity conditions, it spreads through wind, rain, agricultural operations, or soil, invading the root and stem parts and leaf sheaths of crops, leading to symptoms such as leaf sheath rot, stem necrosis, lodging, and even ear withering.

[0003] Currently, the control of wheat and corn sheath blight in agricultural production still relies mainly on chemical pesticides, such as propiconazole, tebuconazole, and thifluzamide, for spraying or seed treatment. Although chemical control can achieve certain disease control effects in the short term, long-term and excessive use of chemical pesticides leads to a series of problems: First, pathogens easily develop resistance, causing the effectiveness of pesticide control to decline year by year, requiring continuous increases in pesticide dosage or changes in pesticide types, creating a vicious cycle; second, pesticide residues pollute soil, water bodies, and air, damaging the farmland ecological environment, affecting the quality and safety of agricultural products, and posing a potential threat to human health; third, long-term reliance on chemical control neglects the regulation of soil microecological balance, leading to decreased soil fertility, pathogen accumulation, and further exacerbating the risk of disease occurrence. Therefore, finding a control technology that can effectively control sheath blight while reducing the use of chemical pesticides, improving soil quality, and promoting green agricultural development has become an important issue that urgently needs to be addressed in the field of crop cultivation and plant protection. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a biological control method for wheat and corn sheath blight, which reduces the incidence of wheat and corn sheath blight and improves soil by combining the application of anti-continuous cropping microbial agents and Greenconway microbial preparations, thereby increasing crop yield.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a biological control method for wheat and corn sheath blight, comprising the following steps: applying a broad-spectrum anti-replanting microecological agent before wheat or corn sowing; and spraying a broad-spectrum Greenconway microbial agent after wheat has turned green or after corn has reached the three-leaf stage.

[0006] Preferably, the application rate of the broad-spectrum anti-replanting microecological agent is 3-7 kg / mu.

[0007] More preferably, the broad-spectrum anti-replanting microecological agent is applied together with crop base fertilizer and then tilled into the soil.

[0008] More preferably, the crop base fertilizer is a nitrogen-phosphorus-potassium ternary compound fertilizer at a rate of 35-45 kg / mu.

[0009] Preferably, the ratio of N:P2O5:K2O in the N:P2O5:K2O in the N:P2O5 compound fertilizer is (15-25):(12-17):(8-17).

[0010] Preferably, the application rate of the broad-spectrum GreenKangWei microbial agent is 20-40g / mu per application.

[0011] More preferably, the broad-spectrum Greenconway microbial agent is diluted 375-750 times and sprayed on the leaves.

[0012] Preferably, the broad-spectrum GreenKangWei microbial agent is sprayed continuously 2-4 times, with an interval of 10-15 days or more between each application.

[0013] Preferably, the application of the broad-spectrum anti-replanting microecological preparation or the broad-spectrum GreenKangWei microbial agent should be avoided during the midday high-temperature period.

[0014] This invention provides the application of the biological control method in the control of wheat and corn sheath blight.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The biological control method of this invention can effectively reduce the incidence of wheat and corn sheath blight, thereby reducing the use of chemical pesticides in agricultural production, lowering chemical pesticide residues, improving the quality of wheat and corn, improving soil, and mitigating non-point source pollution in farmland. It provides biological control technology support for green pest and disease control and the green transformation of agriculture. Specifically: (1) The biological control method of the present invention achieved a disease control rate of 62.5% for wheat sheath blight and 67.65% for corn sheath blight, and the incidence of corn sheath blight in the demonstration site was reduced by 32% compared with the conventional pesticide management plot; (2) Soil nutrient analysis results show that the biological control method of the present invention has a significant effect on promoting the absorption and utilization of soil nutrients by plants. It can increase the contents of soil organic matter, total nitrogen, hydrolyzable nitrogen, available phosphorus and available potassium by 30.72%, 29.29%, 20.41%, 60.00% and 6.90% respectively, increase the content of nutrients that plants can absorb and utilize in the soil, and improve the soil. (3) Using microecological agents to replace chemical pesticides to control diseases can reduce the use of chemical pesticides by more than 3 times, and the reduction effect is significant. The test results show that the biological control method of the present invention increases the yield of wheat and corn by 8.8% and 8.53% respectively. The corn yield in the field demonstration test increased by 9.34% compared with conventional management, and the income per mu of wheat and corn increased by more than 200 yuan. Detailed Implementation

[0016] This invention provides a biological control method for wheat and corn sheath blight, comprising the following steps: applying a broad-spectrum anti-replanting microecological agent before wheat or corn sowing; and spraying a broad-spectrum Greenconway microbial agent after wheat has turned green or after corn has reached the three-leaf stage.

[0017] The broad-spectrum anti-replanting microecological preparation of this invention was purchased from Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd., with registration certificate number Microbial Fertilizer (2018) Approval No. (2893), and an effective viable count ≥ 500 million / gram. This broad-spectrum anti-replanting microecological preparation is a microecological preparation made based on microecological theory, using highly efficient strains such as disease-preventing and growth-promoting Bacillus and Trichoderma, and processed using modern microbial fermentation technology. It mainly works by allowing the strains to colonize, reproduce, and transfer within the crop root surface, rhizosphere, and plant body, fully utilizing the microecological regulatory function of the strains to achieve the effects of preventing soil-borne diseases, solving continuous cropping obstacles, and improving soil. Effective strain names: Bacillus amyloliquefaciens, Bacillus mucilaginosus, Bacillus polymyxa. Application methods: can be applied as a base dressing, in holes or furrows, by root dipping, or by root irrigation.

[0018] The broad-spectrum GreenKangWei microbial inoculant of this invention was purchased from Zhongnong GreenKang (Beijing) Biotechnology Co., Ltd., registration certificate number: Microbial Fertilizer (2018) Approval No. (2699), with an effective viable count ≥35 billion / gram. This broad-spectrum GreenKangWei microbial inoculant is a fifth-generation plant microecological preparation developed based on plant microecology theory to address crop production problems. It is prepared using beneficial endophytic Bacillus and processed with modern microbial fermentation engineering technology. The effective strain is Bacillus amyloliquefaciens. Functional characteristics: regulates plant microecological balance, promotes growth, increases yield; enhances plant resistance to drought, cold, and disease, improves quality, and promotes early maturity. Application methods: can be used for seed dressing, root dipping, root irrigation, and spraying.

[0019] This invention, through the scientific formulation and application of the two microecological preparations, can effectively inhibit the growth of pathogens, enhance crop disease resistance, significantly improve yield and quality, reduce pesticide use, and protect the ecological environment.

[0020] In this invention, the preferred application rate of the broad-spectrum anti-replanting microecological agent is 3-7 kg / mu, more preferably 4-6 kg / mu, and even more preferably 5 kg / mu.

[0021] In this invention, a broad-spectrum anti-replanting microecological agent is preferably applied together with crop base fertilizer and then tilled into the soil. More preferably, the tilling depth is 20-40cm, and more preferably 30cm.

[0022] In this invention, the preferred crop base fertilizer is a NPK ternary compound fertilizer at 35-45 kg / mu, more preferably 40 kg / mu. The N:P2O5:K2O ratio in the NPK ternary compound fertilizer of this invention is (15-25):(12-17):(8-17); when the crop is wheat, it is more preferably N:P2O5:K2O=15:15:15 or 17:17:17 or 25:12:8; when the crop is corn, it is more preferably N:P2O5:K2O=25:10:15.

[0023] In this invention, the preferred application rate of broad-spectrum GreenKangWei microbial agent is 20-40g / mu per application, more preferably 25-35g / mu per application, and even more preferably 30g / mu per application.

[0024] In this invention, it is preferred to use a broad-spectrum Greenconway microbial preparation diluted 375-750 times for foliar spraying, and more preferably diluted 500 times for foliar spraying.

[0025] In this invention, the application of the broad-spectrum anti-replanting microecological preparation or the broad-spectrum GreenKangWei microbial agent should preferably be avoided during the midday high-temperature period.

[0026] In this invention, it is preferred to spray the broad-spectrum GreenKangWei microbial agent 2-4 times consecutively, with an interval of 10-15 days or more between each application; it is even more preferred to spray it 3 times consecutively, with an interval of 15 days or more between each application.

[0027] This invention provides the application of the biological control method in the control of wheat and corn sheath blight.

[0028] 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.

[0029] Example 1 A biological control method for wheat sheath blight includes the following steps: Before wheat sowing, apply 40 kg / mu of NPK 17:17:17 compound fertilizer and 5 kg / mu of broad-spectrum anti-replanting microecological agent (Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.) together, mix thoroughly, and then spread. Afterward, till the soil to a depth of 30 cm. After the wheat turns green, foliar spray 30 g / mu of broad-spectrum Lvkangwei microbial agent (Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.), diluted 500 times, for three consecutive applications. The first and second applications should use 30 g / mu, and the third application should use 60 g / mu, with an interval of at least 15 days between each application. Avoid applying the broad-spectrum anti-replanting microecological agent and the broad-spectrum Lvkangwei microbial agent during the midday heat.

[0030] Example 2 A biological control method for wheat sheath blight includes the following steps: Before wheat sowing, apply 35 kg / mu of NPK 25:12:8 compound fertilizer and 6 kg / mu of broad-spectrum anti-replanting microecological agent (Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.) together, mix thoroughly, and then spread. Afterward, till the soil to a depth of 20 cm. After the wheat turns green, foliar spray 40 g / mu of broad-spectrum Lvkangwei microbial agent (Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.), diluted 375 times, for four consecutive applications, with a 10-day interval between each application. Avoid applying the broad-spectrum anti-replanting microecological agent and the broad-spectrum Lvkangwei microbial agent during the midday heat.

[0031] Example 3 A biological control method for corn sheath blight includes the following steps: The corn trial employed simultaneous seed and fertilizer application. 45 kg / mu of a 25:10:5 NPK compound fertilizer and 4 kg / mu of a broad-spectrum anti-replanting microecological agent (Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.) were applied together with the seed planter. After the corn reached the three-leaf stage, 20 g / mu of a broad-spectrum Lvkangwei microbial agent (Zhongnong Lvkang (Beijing) Biotechnology Co., Ltd.), diluted 750 times, was sprayed on the leaves twice, with a 20-day interval between applications. Note that the application of the broad-spectrum anti-replanting microecological agent and the broad-spectrum Lvkangwei microbial agent should be avoided during the midday high-temperature period.

[0032] Experimental Example 1 I. Wheat or Corn Plot Experiment The scheme is as follows: a total of 4 microecological preparation treatments, 1 conventional chemical pesticide control, and 1 water control were designed. A randomized block design was used, and each treatment and control was replicated 3 times. The treatment methods of each group are shown in Table 1.

[0033] Table 1. Treatment and control table for wheat or corn plot experiments

[0034] The specific method is as follows: Treatment 1 and Treatment 2: Before wheat sowing or at corn sowing, apply 40 kg of compound fertilizer as basal fertilizer and 4 kg / mu or 8 kg / mu of anti-continuous cropping microecological agent (broad-spectrum type). For wheat trials, the microecological agent can be used together with the chemical fertilizer during land preparation, mixed evenly, and then broadcast before tilling. For corn trials, seed and fertilizer are sown simultaneously; the compound fertilizer and microecological agent are mixed evenly and applied to the soil with the seeder. The nitrogen-phosphorus-potassium ratio of the compound fertilizer used for wheat is 25:12:8, and the ratio for corn is 25:10:15.

[0035] Treatment 3: After wheat turns green or after corn reaches the three-leaf stage, spray foliar microecological preparation (broad-spectrum GreenKangWei microbial agent) at a dilution of 500 times, at a rate of 30g / mu-60g / mu (30g GreenKangWei is diluted with 15kg of water to achieve a 500-fold dilution, using a two-stage dilution method, and spray evenly on the plants after mixing). Spray three times consecutively; the dosage for the first and second applications is 30g / mu, and the dosage for the third application is 60g / mu, with an interval of more than 15 days between each application.

[0036] Treatment 4: Apply a basal anti-replanting microecological agent before sowing, and spray the leaves three times during the growing season with a 500-fold dilution of broad-spectrum Greenconway microbial agent. The specific operation method is a combination of treatments 1 and 3.

[0037] Control 1: Only compound fertilizer was applied as basal fertilizer (using the same method as treatment group 1), and no anti-replanting microecological agents were applied. During the growing season, Greenconway spray was not used, but an equal amount (spray volume) of chemical pesticide (tebuconazole) was sprayed as in the treatment.

[0038] Control 2: Only compound fertilizer was applied as basal fertilizer (using the same method as treatment 1), and no anti-replanting microecological agents were applied. During the growing season, no chemical pesticides or Greenconway sprays were used; instead, the same amount of water as the treatments was used for spraying.

[0039] During the wheat or maize experimental plots, all other field management practices were conducted according to standard field management practices. In the later stages of growth, the incidence of wheat or maize sheath blight was investigated. Twenty plants were sampled from each treatment and control plot, and the number of diseased plants was counted. The incidence rate and disease control efficacy were calculated. At harvest season, yield was measured. For wheat yield measurement, three random sampling points were selected from each treatment and control plot, with a 1m² sample taken from each point. 2 (Each community has an area of ​​66m²) 2 The corn was air-dried, threshed, weighed, and the yield per mu was calculated. When measuring the yield of corn, two rows were randomly selected from each treatment and control (12 rows of corn were planted in each plot), air-dried, threshed, and the grain yield was recorded. The yield per mu of the treatment and control was calculated, and the yield increase effect was calculated.

[0040] The incidence rate of sheath blight in each plot (%) = number of diseased plants / number of plants surveyed (20) × 100. The average value of the three replicates is the incidence rate of sheath blight in each treatment and control.

[0041] Disease prevention efficacy of each treatment (%) = (incidence rate of water control - incidence rate of treatment) / incidence rate of water control × 100.

[0042] Wheat yield per plot = 1m 2 The yield of each treatment and control plot is obtained by multiplying the average yield of the three sample plots by 66 and then calculating the average yield of the three replicates.

[0043] The yield of each plot in the maize experiment is calculated as: the sampled yield of each plot × 6. The average of the three replicates is used to obtain the yield of each treatment and control plot.

[0044] The yield increase effect (%) of each treatment on wheat and corn = (treatment yield - water control yield) / water control yield × 100.

[0045] Results of the small-scale test: Table 2. Incidence and control efficacy of various microecological agents for sheath blight in wheat plot trials

[0046] The survey data in Table 2 show that the incidence rates of wheat sheath blight in each treatment were 30.00%, 21.67%, 28.33%, 20.00%, 26.67%, and 53.33%, respectively. Among them, treatment 4, which was basal application of 4 kg of anti-replanting agent and three applications of Green Kangwei spray on plants during the growing season, had the lowest incidence rate of wheat sheath blight and the best control effect, with a control effect of 62.5%.

[0047] Table 3. Yield and yield increase of each treatment in wheat plot experiment.

[0048] Table 3 shows the yield data. The wheat yields of each treatment and the water control plot were 65.34 kg, 66.66 kg, 64.68 kg, 67.98 kg, 64.02 kg, and 62.70 kg, respectively. The yield increase rates of each treatment were 4.58%, 6.34%, 3.87%, 8.80%, and 2.82%, respectively. Among them, treatment 4, which was basal application of 4 kg of anti-replanting agent and three applications of Green Conway spray during the growing season, had the strongest yield increase effect, with a yield increase rate of 8.80% compared with the water control.

[0049] Table 4. Incidence and control efficacy of various microecological agents for sheath blight in maize plot trials.

[0050] Table 4 shows that the incidence rates of corn sheath blight in each treatment were 28.33%, 23.33%, 31.67%, 18.33%, 38.33%, and 56.67%, respectively. Among them, treatment 4, which was basal application of 4 kg of anti-replanting agent and spraying the plants with Green Conway three times during the growing season, had the lowest incidence rate of corn sheath blight and the best control effect, with a control effect of 67.65%.

[0051] Table 5. Yield and yield increase of each treatment in maize plot trials.

[0052] Table 5 shows the yield data. The maize yields of each treatment and the water control plot were 50.94 kg, 51.84 kg, 51.48 kg, 53.94 kg, 52.08 kg, and 49.68 kg, respectively. The yield increase rates of each treatment were 2.50%, 4.35%, 3.62%, 8.53%, and 4.83%, respectively. Among them, treatment 4, which was basal application of 4 kg of anti-replanting agent and three applications of Green Conway spray during the growing season, had the strongest maize yield increase effect, with a yield increase rate of 8.53% compared with the water control.

[0053] II. Field Demonstration Trial of Maize The treatment plan is as follows: 1. Treatment group: Before corn sowing, apply 5 kg of anti-replanting microecological agent as basal fertilizer. After the three-leaf stage, spray with a 500-fold dilution of foliar microecological agent (broad-spectrum Green Kangwei microbial agent), spraying three times consecutively (30 g / mu for the first and second applications, and 60 g / mu for the third application), with an interval of more than 15 days between each application. Other field management measures are the same as the control group. 2. Control group: No microecological agent is used; normal field management is carried out (irrigation, fertilization, chemical pesticide control of pests and diseases, etc.). During the later growth stage, the incidence of corn sheath blight is investigated. Five points are selected for both the treatment and control groups, with 20 plants investigated at each point. The number of diseased plants is counted, and the incidence of sheath blight and the control effect of the treatment are calculated. During the harvest season, samples are taken for yield measurement. Five points are randomly selected from both the treatment and control plots. A 20-meter-long corn cob is taken from each point, naturally air-dried, threshed, and the grain yield is recorded. The yield per mu for the treatment and control groups is calculated, and the yield increase effect is calculated.

[0054] The incidence rate of sheath blight at each treatment and control point (%) = number of diseased plants / number of plants surveyed (20) × 100. The average value of the 5 points is the incidence rate of sheath blight at the treatment and control points.

[0055] The disease prevention effect (%) at the demonstration site = (control incidence rate - treatment incidence rate) / control incidence rate × 100 The yield per mu for treatment and control = average yield of 5 sample points for treatment and control / 12 × 667 (maybe row spacing is 0.6m, 20m long may is 12m long in total). 2 ) The yield increase effect (%) of the demonstration site treatment = (yield per mu of treatment - yield per mu of control) / yield per mu of control × 100 The results of the field demonstration of maize are as follows: Table 6. Incidence of sheath blight in maize demonstration fields treated with microecological agents and compared with conventional chemical pesticides

[0056] Table 6 shows that the average incidence of sheath blight in the corn demonstration field was 79% under conventional chemical pesticide treatment and 47% under microecological agent treatment, which was 32% less than that under conventional chemical pesticide treatment.

[0057] Table 7. Corn yield per mu (unit of land area) under microecological preparation treatment and conventional chemical pesticide control in demonstration fields

[0058] Table 7 shows that the yield of corn in the demonstration field treated with conventional chemical pesticides was 554.50 kg / mu, while the yield of corn treated with microecological agents was 606.30 kg / mu, an increase of 9.34% compared with the control.

[0059] III. Soil Sample Test Results For each treatment (4 treatments and 2 controls, the same as the treatment groups and controls in step one of the plot experiments in this embodiment), 1 kg of topsoil sample was taken from a depth of 30 cm in each wheat and corn plot. After air drying, the organic matter, total nitrogen, hydrolyzable nitrogen, available phosphorus, and available potassium contents of each soil sample were tested by a professional testing agency. The results are shown in Table 8. Table 8. Results of soil sample testing in the plot.

[0060] As shown in Table 8, the contents of organic matter, total nitrogen, hydrolyzable nitrogen, available phosphorus, and available potassium in all treatments of the biocontrol agents were increased to varying degrees compared with the water control. This significantly increased the content of nutrients in the soil and promoted the absorption of nutrients by plants, thus improving the soil and increasing yield. Among them, the anti-replanting agents (treatments 1 and 2) showed a greater increase than the Greenconway microbial agent (treatments 3 and 4). Treatment 2, which involved applying 8 kg of the anti-replanting microecological agent as a basal agent during land preparation, showed the greatest increase in all soil samples compared with the water control (control 2). The contents of organic matter, total nitrogen, hydrolyzable nitrogen, available phosphorus, and available potassium increased by 30.72%, 33.33%, 30.61%, 138.33%, and 12.41%, respectively. Treatment 4, which involved applying 4 kg of anti-replanting fertilizer as a base and spraying the plants with GreenKangwei three times during the growing season, compared with the water control, increased the contents of organic matter, total nitrogen, hydrolyzable nitrogen, available phosphorus, and available potassium by 30.72%, 29.29%, 20.41%, 60.00%, and 6.90%, respectively.

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A biological control method for wheat and corn sheath blight, characterized in that, The process includes the following steps: applying a broad-spectrum anti-replanting microecological agent before wheat or corn sowing; and spraying a broad-spectrum Greenconway microbial agent after wheat has turned green or after corn has reached the three-leaf stage.

2. The biological control method according to claim 1, characterized in that, The application rate of the broad-spectrum anti-replanting microecological agent is 3-7 kg / mu.

3. The biological control method according to claim 1 or 2, characterized in that, The broad-spectrum anti-replanting microecological agent is applied together with crop base fertilizer and then tilled into the soil.

4. The biological control method according to claim 3, characterized in that, The crop base fertilizer is 35-45 kg / mu of NPK compound fertilizer.

5. The biological control method according to claim 4, characterized in that, The ratio of N:P2O5:K2O in the N-P-K ternary compound fertilizer is (15-25):(12-17):(8-17).

6. The biological control method according to claim 1, characterized in that, The application rate of the broad-spectrum Greenconway microbial agent is 20-40g / mu each time.

7. The biological control method according to claim 1, characterized in that, The broad-spectrum Greenconway microbial agent is diluted 375-750 times and applied as a foliar spray.

8. The biological control method according to claim 1, characterized in that, The broad-spectrum GreenKangWei microbial agent is sprayed continuously 2-4 times, with an interval of 10-15 days or more between each application.

9. The biological control method according to claim 1, characterized in that, The application of the broad-spectrum anti-replanting microecological preparation or the broad-spectrum GreenKangWei microbial agent should be avoided during the midday high-temperature period.

10. The application of the biological control method according to any one of claims 1-9 in the control of wheat and maize sheath blight.

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