Method and agent for relieving tobacco root rot and repairing root system

Abstract

The invention discloses a method and a medicament for relieving tobacco root rot and repairing a root system. A tobacco root rot relieving and root system repairing method comprises the following steps that S1, in the first-aid induction stage, 3-5 days after transplanting, induction liquid is applied in a irrigating mode, and the induction liquid comprises chitosan oligosaccharide, betaine, nano SiO2 and ZnSO4; s2, a slow-release protection stage: 3-7 days after irrigation, chitosan and gelatin coated controlled-release particles are applied to the tobacco root zone, the controlled-release particles comprise mannitol, water-soluble zinc and potassium humate, and the pH value of the root zone is maintained to be 6.0-6.8; s3, an ecological maintenance stage, the period is 15 days, a nutrient solution is applied, and the nutrient solution comprises organic acid, amino acid calcium and magnesium nitrate. The invention provides a green scheme without chemical pesticides and exogenous strains, and the control effect of the root rot is not less than 70%; the root system damage repair time is shortened; the root zone microenvironment is continuously regulated for more than or equal to 15 days.

Description

Technical Field

[0001] This invention belongs to the field of disease control technology, specifically relating to a method and agent for alleviating tobacco root rot and repairing the root system. Background Technology

[0002] Tobacco root rot (pathogen Fusarium solani / Pythium spp.) can cause an average annual yield loss of 15-30% in tobacco. Conventional chemical fungicides (such as carbendazim) are prone to causing excessive residues and pathogen resistance. Transplanted root damage repair is slow (traditionally requiring 10-15 days), delaying growth and reducing nicotine synthesis efficiency. Existing biological agents (such as Bacillus subtilis) have a colonization success rate of <40% in continuously cropped soils.

[0003] Single application of silicon / zinc elements has a control efficacy of only 35-50% against root rot and lacks damage repair function. Chitosan-induced resistance requires high-frequency application (3-5 days / time), resulting in high operating costs; microecological regulators (such as humic acid) have a short retention time in the root zone (<72 hours), making it difficult to sustainably inhibit pathogens. Therefore, this invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a method and agent for alleviating tobacco root rot and repairing root system damage, achieving efficient relief of tobacco root rot and rapid repair of root damage. It is suitable for sustainable tobacco cultivation and management and has the characteristics of being green, safe, and free of pesticide residues.

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

[0006] A method for alleviating tobacco root rot and repairing the root system includes the following steps:

[0007] S1. Emergency induction stage, 3-5 days after transplanting: Drench with induction solution, which includes 200-400 mg / L of chitosan oligosaccharide, 0.05-0.1% of betaine, 50-100 mg / L of nano-SiO2 and 0.02-0.05% of ZnSO4;

[0008] S2, Slow-release protection stage, 3-7 days after irrigation: Apply chitosan and gelatin-coated controlled-release granules to the tobacco root zone. The controlled-release granules include 2-5% mannitol, 0.5-1.5% water-soluble zinc and 1-3% potassium humate to maintain the pH of the root zone at 6.0-6.8.

[0009] S3, Ecological Maintenance Stage, with a cycle of 15 days: Irrigation with nutrient solution, which includes 0.2-0.3% organic acid, 0.1-0.3% amino acid calcium and 0.05-0.1% magnesium nitrate.

[0010] In the above method, the amount of induction solution applied is 200 mL / plant.

[0011] In the above method, the chitosan and gelatin coating is prepared by cross-linking chitosan and gelatin with glutaraldehyde.

[0012] In the above method, the mass ratio of chitosan to gelatin is 7:3.

[0013] In the above method, the chitosan and gelatin coating film has a thickness of 50 μm.

[0014] In the above method, the amount of controlled-release granules applied is 20g / hole.

[0015] In the above method, the organic acid includes citric acid and / or malic acid.

[0016] In the above method, the mass ratio of citric acid to malic acid is 2:1.

[0017] In the above method, the amount of nutrient solution applied is 150 mL / plant.

[0018] An agent for alleviating tobacco root rot and repairing root system includes at least one of the inducing solution, the controlled-release granules, and the nutrient solution described in any of the above methods.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. This invention provides a green solution without chemical pesticides or exogenous bacteria, simultaneously achieving root rot prevention efficacy ≥70%; shortening root damage repair time; and continuous regulation of the root zone microenvironment for ≥15 days.

[0021] 2. This invention is based on silicon-zinc dual regulation and polysaccharide induction to alleviate tobacco root rot and repair the root system. SiO2 can enter the endodermis via the apoplast pathway and synergistically activate the disease resistance gene NtPR1 with zinc, increasing its expression. Chitosan and gelatin coatings undergo gradient disintegration in the acidic rhizosphere environment, releasing potassium humate which chelates the Fe required by the pathogen. 3+ (The inhibition rate against pathogens is >90%).

[0022] 3. The agent of this invention is free of chemical pesticides and exogenous bacteria, and can effectively inhibit pathogens, improve root growth and tobacco quality. Attached Figure Description

[0023] Figure 1 This is a photograph of the root system of a tobacco plant after treatment in Example 1. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods.

[0025] In this invention, percentages represent the mass percentage of the corresponding components.

[0026] A method for alleviating tobacco root rot and repairing the root system includes the following steps:

[0027] S1. Emergency Induction Stage, 3-5 days after transplanting: Apply induction solution by irrigation, at a rate of 200 mL / plant. The induction solution includes 200-400 mg / L chitosan oligosaccharide, 0.05-0.1% betaine, 50-100 mg / L nano-SiO2, and 0.02-0.05% ZnSO4. The induction solution can stimulate auxin (IAA) secretion and promote callus formation (starting within 24 hours).

[0028] S2. Slow-release protection stage, 3-7 days after irrigation: Apply chitosan and gelatin-coated controlled-release granules to the tobacco root zone at a rate of 20g / hole. The controlled-release granules contain 2-5% mannitol, 0.5-1.5% water-soluble zinc, and 1-3% potassium humate to maintain the root zone pH at 6.0-6.8 and inhibit pathogen spore germination.

[0029] The chitosan and gelatin coating is prepared by crosslinking chitosan and gelatin with glutaraldehyde, and the preferred mass ratio of chitosan to gelatin is 7:3. The chitosan and gelatin coating film thickness is 50 μm.

[0030] S3, Ecological Maintenance Stage, with a cycle of 15 days: Apply nutrient solution at a rate of 150 mL per plant. The nutrient solution includes 0.2-0.3% organic acid, 0.1-0.3% amino acid calcium, and 0.05-0.1% magnesium nitrate. The nutrient solution can enhance calcium flow (Ca2+) in the xylem vessels. + (The transportation volume increased by more than 30%), blocking the channels for pathogen infection.

[0031] Organic acids include citric acid and / or malic acid. When citric acid and malic acid are combined, the mass ratio of citric acid to malic acid is 2:1.

[0032] Example 1: Application of Yunnan flue-cured tobacco transplanting (red soil, pH=5.8)

[0033] A method for alleviating and repairing tobacco root rot involves treating Yunnan flue-cured tobacco plants that have been infected with root rot for approximately two weeks. The method includes the following steps:

[0034] S1, Emergency Induction Stage, 3-5 days after transplanting:

[0035] The induction solution consisted of 300 mg / L chitosan oligosaccharide, 0.08% betaine, 80 mg / L nano-SiO2 (30 nm particle size) and 0.03% ZnSO4.

[0036] On the 4th day after transplanting, apply an induction solution in a ring 5cm away from the base of the stem, at a rate of 200mL per plant.

[0037] S2, Slow-release protection phase, 3-7 days after application:

[0038] The controlled-release granules contain 4% mannitol, 1% EDTA-Zn, 2% potassium humate, and 93% bentonite carrier, maintaining the root zone pH at 6.0.

[0039] Chitosan and gelatin coating is prepared by crosslinking chitosan and gelatin with glutaraldehyde. Chitosan and gelatin are mixed at a mass ratio of 7:3 and stirred in a 50°C constant temperature water bath until homogeneous. Then, a 2% (w / w) glutaraldehyde solution is slowly added dropwise, and the reaction is continued with stirring for 1 hour to form a crosslinked composite colloidal solution. This solution is sprayed onto the surface of controlled-release particles and dried to form a coating layer. The chitosan and gelatin coating film is 50 μm thick.

[0040] Five days after irrigation, apply chitosan and gelatin-coated controlled-release granules at a depth of 10 cm from the roots in the tobacco root zone, at a rate of 20 g per hole.

[0041] S3, the ecological maintenance phase, lasts 15 days:

[0042] The nutrient solution contains 0.2% citric acid, 0.2% calcium amino acids, and 0.08% magnesium nitrate, with a pH of 6.0.

[0043] Apply nutrient solution every 15 days at a rate of 150 mL per plant, for a total of 3 cycles.

[0044] The efficacy survey results showed that the method in this embodiment achieved a 76.4% control rate for root rot, and significantly increased the number of new roots. Figure 1 As shown. Furthermore, using the method of this invention, tobacco root rot can be controlled in approximately 9 days initially, and the health of the root system gradually improves.

[0045] Comparative Example 1

[0046] The tobacco variety and soil were the same as in Example 1. To control root rot in tobacco plants, on the 4th day after transplanting, nano-zinc oxide was applied in a ring 5cm from the base of the stem at a rate of 200mL per plant, 2-3 times per month. Repair was completed in about three weeks, and the plants resumed normal growth. The method in Comparative Example 1 showed a 50% control efficacy against root rot and lacked damage repair capabilities, requiring the use of other fertilizers for root system repair.

[0047] The potassium content in the tobacco leaves of Example 1 and Comparative Example 1 was measured on day 6 and day 10, respectively, and the results are shown in Table 1.

[0048] Table 1

[0049] Potassium content of tobacco leaves Day 6 Day 10 Example 1 1.8％ 2.2％ Comparative Example 1 1.7％ 1.9％

[0050] The results showed that the potassium content of the tobacco leaves in Example 1 was significantly increased, resulting in an increase in output value of 1420 yuan / mu. The potassium content of the tobacco leaves in Comparative Example 1 recovered more slowly, and the potassium content level was not as high as that in Example 1.

[0051] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for tobacco pythium root rot mitigation and root repair, comprising, The method comprises the following steps: S1, emergency induction stage, 3-5 days after transplanting: irrigation of an induction solution, the induction solution comprising 200-400 mg / L of chitosan oligosaccharide, 0.05-0.1% of betaine, 50-100 mg / L of nano-SiO2, and 0.02-0.05% of ZnSO4; S2, slow-release protection stage, 3-7 days after irrigation: application of chitosan and gelatin coated controlled-release particles in the root zone of the tobacco, the controlled-release particles comprising 2-5% of mannitol, 0.5-1.5% of water-soluble zinc, and 1-3% of humic acid potassium, maintaining the pH of the root zone at 6.0-6.8; S3, ecological maintenance stage, a period of 15 days: irrigation of a nutrient solution, the nutrient solution comprising 0.2-0.3% of organic acid, 0.1-0.3% of calcium amino acid, and 0.05-0.1% of magnesium nitrate.

2. The method of claim 1, wherein, The application amount of the induction solution is 200 mL / plant.

3. The method of claim 1, wherein, The chitosan and gelatin coating is prepared by cross-linking chitosan and gelatin with glutaraldehyde.

4. The method of claim 3, wherein, The mass ratio of the chitosan to the gelatin is 7:

3.

5. The method of claim 1, wherein, The chitosan and gelatin coating film has a thickness of 50 μm.

6. The method of claim 1, wherein, The application amount of the controlled-release particles is 20 g / hole.

7. The method of claim 1, wherein, The organic acid comprises citric acid and / or malic acid.

8. The method of claim 7, wherein, The mass ratio of the citric acid to the malic acid is 2:

1.

9. The method of claim 1, wherein, The application amount of the nutrient solution is 150 mL / plant.

10. An agent for alleviating tobacco black root rot and for repairing root system, characterized by, At least one of the induction solution, the controlled-release particles, and the nutrient solution in the method of any one of claims 1-9 is included.

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