Tobacco floating seedling disease prevention and control method

Abstract

The invention relates to the technical field of tobacco disease prevention and control methods, in particular to a tobacco floating seedling disease prevention and control method. Comprising the following steps: adding a mixed disinfectant of 20-30 g / m < 3 > of trichloroisocyanuric acid, 20-30 g / m < 3 > of thiophanate methyl and 5-8 g / m < 3 > of moroxydine hydrochloride into each floating nursery pond; in the floating seedling raising process, terahertz wave treatment is continuously applied to the floating seedling raising pond; a small amount of disinfectant combination with a specific proportion is added into the floating seedling raising pond, terahertz wave treatment is applied to the floating seedling raising pond, fumigation and other disinfection means are matched, the disease infection rate of the tobacco seedlings can be completely controlled to be 0%, and tobacco seedling growth hindering caused by phytotoxicity is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of tobacco disease prevention and control methods, and in particular to a tobacco floating seedling disease prevention and control method. Background Art

[0002] Floating seedling cultivation of tobacco is a modern seedling cultivation technology that combines soilless cultivation with precise environmental control. Its core principles are based on the following key links: matrix function: the use of lightweight porous matrix (such as peat soil, perlite, etc.) can not only fix the roots of tobacco seedlings, but also absorb water and nutrients in the nutrient solution through capillary action to achieve continuous supply; water bed function: the seedling tray floats in a pool of nutrient solution, and the water body provides a stable temperature buffer (due to the large specific heat capacity of water), reducing the impact of external environmental fluctuations on the root system; the tobacco seedlings contact the nutrient solution through the pores of the matrix, and the roots directly absorb nitrogen, phosphorus, potassium and other mineral elements from the water bed. At the same time, oxygen enters the root system through the pores of the matrix to ensure normal respiration.

[0003] In the prior art, seedling trays and pools need to be strictly disinfected (such as using bleaching powder or formalin) to block the spread of soil-borne diseases. However, existing disinfection methods cannot completely avoid common diseases in the seedling raising process, such as damping-off disease, root rot, black stem disease, common mosaic disease, wildfire disease, bacterial wilt, etc., which lead to tobacco production reduction. The Chinese patent with publication number CN113575237A discloses a disease prevention and control method based on improving the comprehensive resistance of tobacco, which discloses that one day before cutting the leaves, a 600-fold dilution containing 25g of 30% morpholinoguanidine hydrochloride is sprayed per mu. One day before and after sealing the tray, a 15kg aqueous solution containing 10 ml of island oligosaccharide and 100g of green land health is sprayed per mu, and a second spraying is performed after an interval of 8 days. One day before seedling emergence, a 750-fold dilution containing 20g of 20% cintamidine is sprayed per mu. However, tobacco leaves still suffer from disease. On the other hand, although the method of using a large amount of disinfectants to prevent and control tobacco seedling diseases can effectively improve the disease rate of tobacco seedlings, the disinfectants themselves will cause certain phytotoxicity to the tobacco seedlings, such as a decrease in the activity of anti-stress enzymes, resulting in a decrease in anti-stress activity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is: how to improve the tobacco floating seedling disease prevention and control method, which can not only effectively improve the disease rate of tobacco seedlings, but also improve the anti-stress enzyme activity of tobacco seedlings after seedling cultivation.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A tobacco floating seedling disease prevention and control method comprising:

[0007] Each floating nursery pond is added with 20-30g / m3 of trichloroisocyanuric acid 3, thiophanate methyl 20-30g / m 3 , morpholinoguanidine hydrochloride 5-8g / m 3 Mix disinfectant;

[0008] During the floating seedling cultivation process, terahertz wave treatment is continuously applied to the floating seedling cultivation pond.

[0009] Furthermore, in the above tobacco floating seedling disease prevention and control method, the frequency of the terahertz wave is 0.5-10 THz.

[0010] Furthermore, the above tobacco floating seedling disease prevention and control method also includes comprehensive disinfection and pest control of weeds, ground and outer film around the tobacco seedling shed before seedling cultivation begins.

[0011] Furthermore, in the above-mentioned tobacco floating seedling disease prevention and control method, the weeds, ground and outer film around the tobacco seedling shed are fully disinfected and deinsectized as follows: 100 times diluted trichloroisocyanuric acid and 500 times diluted chlorflucythrinate are mixed, and the weeds, ground and outer film around the tobacco seedling shed are fully sprayed for disinfection and deinsectization.

[0012] Furthermore, the above tobacco floating seedling disease prevention and control method also includes fumigating the seedling shed with trichloroisocyanuric acid fumigant before the seedling cultivation begins.

[0013] Furthermore, in the above-mentioned tobacco floating seedling disease prevention and control method, the fumigation treatment is specifically as follows: pour 200g of trichloroisocyanuric acid fumigant into a 500mL beaker, place it on an electronic heating table, place the electronic heating table in the seedling shed, set the temperature to 250°C, and heat for 30 minutes. After heating until smoke appears, close the seedling shed for 12 hours, and then open for ventilation for 2 hours.

[0014] Furthermore, the above-mentioned tobacco floating seedling disease prevention and control method also includes disinfecting the tobacco seedlings themselves during thinning.

[0015] Furthermore, in the aforementioned tobacco floating seedling disease control method, during thinning, the tobacco seedlings are disinfected as follows: At each thinning location, a 20cm x 50cm x 30cm plastic box is placed. 40g of manganese zinc formate, 20g of amino oligosaccharides, and 20g of thiazolinone are added, followed by water and stirring until the mixture reaches a height of 25cm. Immediately after thinning each tray of tobacco seedlings, a 40cm-wide soft-bristled brush dipped in the aforementioned mixture is used to gently brush the entire tray of seedlings to ensure even coverage.

[0016] Furthermore, the above-mentioned tobacco floating seedling disease prevention and control method also includes installing a spray disinfection device for spray disinfection after leaf cutting. The device includes an aluminum chassis, movable rollers, a tray with a fixing screw in the middle, a hook for connecting to a leaf cutter, and a 25L electric sprayer. Before the tobacco seedlings begin to be cut, 50g of formic acid and mexamethylenetetramine, 40g of morphoguanidine hydrochloride, and 50g of closatin 3000 powder are poured into the electric sprayer, and water is added to 25L, and stirred evenly. The electric sprayer is equipped with a motion sensor switch. When leaf cutting begins, the spray disinfection device is loaded with the above-mentioned chemicals, connected to the leaf cutter, and the electric sprayer switch is turned on. Once the leaf cutter starts to work, the spray disinfection device is immediately turned on to spray disinfect the tobacco seedlings after cutting.

[0017] The beneficial effects of the present invention are as follows: by adding a small amount of disinfectant combination in a specific ratio to the floating seedling nursery pond, applying terahertz wave treatment in the floating seedling nursery pond, and combining it with fumigation and other disinfection methods, the present invention can completely control the disease rate of tobacco seedlings to 0% and avoid the growth retardation of tobacco seedlings caused by pesticide damage;

[0018] By installing spray disinfection equipment for leaf cutting, the cut leaf parts can be disinfected in time before and after the leaf cutting process. Compared with the original method of spraying separately after the leaf cutting is completed, the amount of disinfectant used can be reduced, and at the same time, the cut leaf parts can be avoided from being infected with bacteria due to delayed disinfection. DETAILED DESCRIPTION

[0019] To explain the technical content, achieved objectives and effects of the present invention in detail, the following describes them in conjunction with the implementation methods.

[0020] Example 1

[0021] A tobacco floating seedling disease prevention and control method comprises the following steps:

[0022] Before starting seedling cultivation, mix a 100-fold dilution of trichloroisocyanuric acid and a 500-fold dilution of lambda-cyhalothrin to thoroughly disinfect and eliminate weeds, the ground, and the outer film around the tobacco seedling shed.

[0023] Pour 200g of trichloroisocyanuric acid fumigant into a 500mL beaker and place it on an electronic heating table. The electronic heating table is placed in a seedling shed and the temperature is set to 250°C for 30 minutes. After heating until smoke appears, the seedling shed is sealed for 12 hours and then ventilated for 2 hours. The volume of each floating seedling pond is 0.3 cubic meters, and a mixed disinfectant consisting of 8g of trichloroisocyanuric acid, 8g of thiophanate-methyl, and 2g of guanidine hydrochloride is added to each floating seedling pond.

[0024] During the floating seedling cultivation process, terahertz waves are continuously applied to the floating seedling cultivation pool, and the frequency of the terahertz waves is 5THz.

[0025] During tobacco seedling thinning, place a 20cm x 50cm x 30cm plastic box at each thinning location. Add 40g of manganese zinc formate, 20g of amino oligosaccharides, and 20g of thiazolinone, then add water to a height of 25cm and mix thoroughly. Immediately after thinning each tray of tobacco seedlings, use a 40cm wide soft-bristled brush dipped in the above-mentioned mixture and gently brush the entire tray to evenly coat it with the mixture.

[0026] A spray disinfection device was added for spray disinfection after leaf cutting. The device includes an aluminum chassis, movable rollers, a tray with a fixing screw in the middle, a hook for connecting to the leaf cutter, and a 25L electric sprayer. Before the tobacco seedlings begin to be cut, 50g of formic acid and mexamethylenetetramine, 40g of morphoguanidine hydrochloride, and 50g of closatin 3000 powder were poured into the electric sprayer, and water was added to 25L and stirred evenly. The electric sprayer was equipped with a motion sensor switch. When leaf cutting began, the spray disinfection device was loaded with the above-mentioned drugs, connected to the leaf cutter, and the electric sprayer switch was turned on. After the leaf cutter started to work, the spray disinfection device was immediately turned on to spray disinfect the tobacco seedlings after the leaves were cut.

[0027] In the above embodiment, the floating nursery pond is continuously treated with terahertz waves, specifically through the photoconductive antenna (PCA) is achieved by using femtosecond laser pulses (such as titanium sapphire laser) to irradiate semiconductor materials (such as Gallium arsenide or low temperature grown gallium arsenide LT-GaAs), by applying a bias voltage (DC or high frequency), the carrier movement is accelerated to produce The transient current is generated, and the rapid change of the current radiates broadband terahertz radiation through the antenna structure (such as a dipole or spiral electrode). Pulse, encapsulate the antenna in a material that transmits terahertz waves (such as high-resistance silicon, polyethylene or quartz window) to avoid direct contact with liquid The semiconductor directs the terahertz waves into the pool water through the window.

[0028] Comparative Example 1

[0029] On the basis of Example 1, the step of continuously applying terahertz wave treatment to the floating seedling pond during the floating seedling cultivation process, with the terahertz wave frequency being 5 THz, is omitted, and the other steps remain unchanged.

[0030] Comparative Example 2

[0031] On the basis of Example 1, the step of continuously applying terahertz wave treatment to the floating seedling pond during the floating seedling cultivation process with a terahertz wave frequency of 5 THz was omitted, and each floating seedling pond was instead added with a mixed disinfectant consisting of 100 g of trichloroisocyanuric acid, 100 g of thiophanate-methyl, and 40 g of guanidine hydrochloride.

[0032] Comparative Example 3

[0033] On the basis of Example 1, the step of continuously applying terahertz wave treatment to the floating seedling pond during the floating seedling cultivation process with a terahertz wave frequency of 5 THz is omitted, and the addition of a mixed disinfectant consisting of 8 g of trichloroisocyanuric acid, 8 g of thiophanate-methyl and 2 g of guanidine hydrochloride to each floating seedling pond is omitted, and the other steps remain unchanged.

[0034] Experimental example

[0035] In the same seedling shed, 4 groups of seedling pools were set up, with 3 seedling pools in each group; the first group adopted the tobacco floating seedling disease prevention and control method, the second group adopted the tobacco floating seedling disease prevention and control method of comparative example 1, the third group adopted the tobacco floating seedling disease prevention and control method of comparative example 2, and the fourth group adopted the tobacco floating seedling disease prevention and control method of comparative example 3. After 60 days of seedling cultivation, 10 tobacco seedlings were randomly selected from each group of tobacco seedlings, and the seedling height and stem circumference of the tobacco seedlings were measured, and the average value was taken.

[0036] The activity of POD (Potassium oxidase) was tested on the extracted tobacco seedlings as follows:

[0037] 1-3 g of fresh root, stem, or leaf tissue from tobacco seedlings was minced and added to pre-chilled phosphate buffer (pH 7.0-7.8, 0.05-0.1 mol / L). The tissue was then ground into a homogenate in an ice bath, with a homogenate volume to tissue mass ratio of 5-10 mL / g. Samples with high plant fiber content (e.g., stems) were subjected to ultrasonication (power 200-300 W, ultrasound 3 s / 7 s interval, total duration 3-5 min). The homogenate was centrifuged at 8000-12000 × g for 10-15 minutes at 4°C. The supernatant was used as the enzyme solution to be tested and stored at low temperature until further use. A reaction mixture was prepared: 2.9 mL of 0.1 M phosphate buffer (pH 5.5-7.0); 1 mL of 0.1% guaiacol solution; and 0.18%-2% 1 mL of H2O2 solution; 0.1 mL of homogenate; react in a 37°C water bath in the dark for 15 minutes, or at 30°C until a brown-red product is formed; add 2 mL of 20% trichloroacetic acid (TCA) or distilled water to terminate the reaction, filter, and measure absorbance; measure the absorbance change of the reaction product at a wavelength of 470 nm, using a blank control group (containing inactivated enzyme solution) as the baseline. A change of 0.01 absorbance per minute is considered 1 unit (U) of enzyme activity.

[0038] The POD activity of the sample was calculated using the formula:

[0039]

[0040] Where:

[0041] ΔOD 470: absorbance change;

[0042] D: enzyme solution dilution multiple;

[0043] t: reaction time (min);

[0044] W: sample fresh weight (g);

[0045] The disease conditions of all tobacco seedlings in each group were counted (including damping-off disease, root rot, black stem disease, common mosaic disease, wildfire disease, bacterial wilt, etc.), and the disease rate of each group was calculated.

[0046] The experimental results are as follows:

[0047] Group 1 (Example 1): average seedling height 15.28 cm, average stem girth 1.05 cm, disease infection rate 0%, average POD activity 503.424 U / g (fresh weight);

[0048] The second group (comparative example 1): the average seedling height was 14.28 cm, the average stem circumference was 0.95 cm, the infection rate was 3.52%, and the average POD activity was 405.822 U / g (fresh weight);

[0049] Group 3 (Comparative Example 2): average seedling height 12.37 cm, average stem girth 0.76 cm, disease infection rate 0.52%, average POD activity 328.418 U / g (fresh weight);

[0050] The fourth group (Comparative Example 3): the average seedling height was 14.96 cm, the average stem girth was 0.99 cm, the disease infection rate was 0.24%, and the average POD activity was 465.316 U / g (fresh weight).

[0051] The experimental results show that in Example 1, by adding a disinfectant combination in a specific proportion and dosage to the seedling pond and continuously applying terahertz wave treatment to the floating seedling pond, the growth of tobacco seedlings can be effectively promoted, the infection rate is completely reduced to 0, and the average POD activity is the highest, reaching 503.424 U / g.

[0052] Discussion of experimental results: Although directly adding a large amount of disinfectant to the floating nursery pond can effectively prevent and control tobacco seedling disease, it will also lead to a decrease in POD activity, reduce the stress resistance of tobacco seedlings, and hinder the growth of tobacco seedlings to a certain extent. The solution of the present invention (Example 1) adds a small amount of disinfectant combination in a specific proportion to the floating nursery pond, applies terahertz wave treatment in the floating nursery pond, and combines with fumigation and other disinfection methods to completely control the disease rate of tobacco seedlings to 0%, and avoid the growth hindrance of tobacco seedlings caused by pesticide damage. Terahertz waves can not only destroy the cell membrane structure of microorganisms such as viruses through high-frequency vibration, achieve significant inactivation effects on common pathogens such as Escherichia coli and bacterial wilt bacteria in the water of seedling ponds, and reduce the risk of water-borne diseases such as root rot and sudden wilt in tobacco seedlings; high-frequency vibration can also significantly inactivate common pathogens such as Escherichia coli and bacterial wilt bacteria in the water of seedling ponds, reduce the risk of water-borne diseases such as root rot and sudden wilt in tobacco seedlings, retain essential minerals such as calcium and magnesium in the water after treatment, and avoid the loss of nutrients caused by traditional chemical disinfection. Terahertz waves convert water molecules from a polymerized state (large molecules) into a small molecule structure with a linear arrangement (molecular weight reduced by 680 times), enhancing the permeability and solubility of water molecules. Small molecule water is more easily absorbed by the roots of tobacco seedlings, improving the transport efficiency of water and nutrients, and promoting the metabolism of seedlings. After treatment, the viscosity of the water body is reduced, and the dissolved oxygen content is increased by more than 30%, alleviating the problem of root rot caused by lack of oxygen in the seedling pond water.

[0053] On the other hand, by installing spray disinfection equipment for leaf cutting, the cut leaf parts can be disinfected in time before and after the leaf cutting process. Compared with the original method of spraying separately after the leaf cutting is completed, the amount of disinfectant used can be reduced, and at the same time, the cut leaf parts can be avoided from being infected with bacteria due to delayed disinfection.

[0054] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention specification, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A tobacco floating seedling disease prevention and control method, characterized in that: include: Each floating nursery pond is added with 20-30g / m3 of trichloroisocyanuric acid 3 , thiophanate methyl 20-30g / m 3 , morpholinoguanidine hydrochloride 5-8g / m 3 Mix disinfectant; During the floating seedling cultivation process, terahertz wave treatment is continuously applied to the floating seedling cultivation pond.

2. The tobacco floating seedling disease prevention and control method according to claim 1, characterized in that: The frequency of the terahertz wave is 0.5-10 THz.

3. The tobacco floating seedling disease prevention and control method according to claim 1, characterized in that: It also includes comprehensive disinfection and pest control of weeds, ground and outer film around the tobacco seedling shed before seedling cultivation begins.

4. The tobacco floating seedling disease prevention and control method according to claim 3, characterized in that: The weeds, ground and outer film around the tobacco seedling shed are thoroughly disinfected and de-insectized. Specifically, a 100-fold diluted solution of trichloroisocyanuric acid and a 500-fold diluted solution of highly effective chlorflucythrinate are mixed, and the weeds, ground and outer film around the tobacco seedling shed are thoroughly sprayed for disinfection and de-insectization.

5. The tobacco floating seedling disease prevention and control method according to claim 1, characterized in that: It also includes fumigating the seedling shed with trichloroisocyanuric acid fumigant before the seedling cultivation begins.

6. The tobacco floating seedling disease prevention and control method according to claim 5, characterized in that: The fumigation treatment is specifically as follows: pour 200g of trichloroisocyanuric acid fumigant into a 500mL beaker, place it on an electronic heating table, place the electronic heating table in the seedling shed, set the temperature to 250℃, and the time for 30 minutes. After heating until smoke appears, close the seedling shed for 12 hours, and then open for ventilation for 2 hours.

7. The tobacco floating seedling disease prevention and control method according to claim 1, characterized in that: It also includes the disinfection of the tobacco seedlings themselves during thinning.

8. The tobacco floating seedling disease prevention and control method according to claim 1, characterized in that: During thinning, the tobacco seedlings should be disinfected as follows: Place a 20cm x 50cm x 30cm plastic box at each thinning location, add 40g of manganese zinc formate, 20g of amino oligosaccharide, and 20g of thiazolinone, then add water to a height of 25cm and stir evenly. Immediately after thinning each tray of tobacco seedlings, use a 40cm wide soft-bristled brush dipped in the above-mentioned mixture and gently brush the entire tray to evenly coat it with the mixture.

9. The tobacco floating seedling disease prevention and control method according to claim 1, characterized in that: It also includes the installation of spray disinfection equipment for spray disinfection of leaf cutting. The equipment includes an aluminum chassis, movable rollers, a tray with fixed screws in the middle position and a hook connected to the leaf cutter, as well as an electric sprayer with a capacity of 25L. Before the tobacco seedlings start to be cut, 50g of formic acid·hypromexyl, 40g of morpholino hydrochloride, and 50g of chloramphenicol 3000 powder are poured into the electric sprayer, and water is added to 25L and stirred evenly; the electric sprayer is equipped with a motion sensing switch. When the leaf cutting starts, the spray disinfection equipment is loaded with the above-mentioned agents, connected to the leaf cutter, and the electric sprayer switch is turned on. After the leaf cutter moves to work, the spray disinfection equipment is immediately turned on to spray disinfect the tobacco seedlings after the leaves are cut.

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