A method for cultivating strong cigar seedlings at high temperature in the early stage

Abstract

The invention discloses a method for raising seedlings of cigar tobacco under high temperature in the early stage, including the steps of preparing a seedling pool, sterilizing seedling trays, loading substrates, sowing, water management, fertilization management, temperature and humidity management, thinning, leaf cutting, seedling hardening and disease prevention, wherein water management is operated in a shallow water seedling raising and dry-wet alternating manner, adding a special fertilizer for cigar seedling raising for the first time when the tobacco seedlings grow to the cross stage, adding a special fertilizer for cigar seedling raising for the second time after the first leaf cutting, hanging a thermometer and hygrometer in the seedling raising shed after sowing, monitoring the temperature and humidity changes in the seedling shed during the seedling raising period in real time, regulating the temperature and humidity in the shed by covering a sunshade net and ventilating the seedling raising shed around, and taking 3 leaf cutting operations. The present invention uses wet seedling raising and supporting technical measures to carry out seedling cultivation, effectively overcomes the high temperature obstacle in the early stage of Hainan cigar tobacco seedling raising, achieves the purpose of reducing the number of slender seedlings with stems, cultivating high-quality cigar tobacco seedlings, and promoting the growth quality after transplanting.

Description

Technical Field

[0001] The invention relates to a seedling raising method for cultivating strong cigar seedlings at high temperature in the early stage, belonging to the technical field of cigar seedling raising. Background Art

[0002] In recent years, my country's cigar industry has developed rapidly, and the demand for cigar tobacco raw materials has continued to increase. To this end, cigar tobacco growing areas such as Hainan, Sichuan, Hubei, and Yunnan are increasing their research efforts on key production technologies for cigar tobacco raw materials to continuously meet the needs of cigar tobacco industrial enterprises for high-quality raw materials. Among them, seedling cultivation is an important link that affects the production of high-quality cigar tobacco raw materials.

[0003] Hainan has the natural ecological conditions for producing high-quality cigar tobacco raw materials and is the production area with the greatest potential advantages in developing cigar tobacco raw material production in my country. At present, multiple seedling raising methods such as floating seedling raising and tray seedling raising coexist in tobacco areas, and they are not the same between regions and different years. The quality of tobacco seedlings is unstable and the level of seedling raising intensiveness is not high. At the same time, combined with ecological and climatic conditions, drying room matching and other factors, Hainan's cigar tobacco areas often adopt batch sowing and seedling raising from September and October each year to January and February of the following year, with the seedling raising being more concentrated in October. During this period, except for the temperature drop from December to January of the following year, the temperature in the seedling raising shed is mostly above 30°C, especially from late September to mid-to-late November. As a result, the tobacco seedlings sown from late September to mid-to-late October, regardless of whether they are raised by floating seedlings or tray seedlings, have fast emergence and fast early growth, but thin stems and underdeveloped root systems. In early December, the temperature drops again, and the tobacco seedlings have low resistance, resulting in low overall quality. Summary of the invention

[0004] Based on the above, the present invention provides a seedling raising method for cultivating strong cigar seedlings under high temperature in the early stage, which overcomes the high temperature obstacle in the early stage of Hainan cigar tobacco seedling raising by moist seedling raising and matching technical measures, thereby achieving the purpose of reducing the number of thin seedlings with stalks, cultivating high-quality cigar seedlings, and promoting the growth quality after transplanting.

[0005] The technical solution of the present invention is: a method for cultivating strong cigar seedlings at high temperature in the early stage, the method comprising:

[0006] 1) Make a nursery pond;

[0007] 2) Seedling tray disinfection: The number of holes in the seedling tray is 70 to 100, and the seedling tray should be disinfected before sowing;

[0008] 3) Matrix loading: Add water to the moist matrix and stir continuously to make the matrix slightly moist, so that it can be held in the hand and fall apart at the touch. Then fill the holes of the seedling tray with the matrix evenly, lift the seedling tray with both hands, release both hands and let the seedling tray fall vertically, repeat 2-3 times, and finally scrape off the excess matrix on the tray surface and the edge of the seedling tray;

[0009] 4) Sowing: Plant the seeds into the hole matrix, and place the seedling trays into the seedling pool in turn after sowing. The water depth of the seedling pool after placing the seedling trays is maintained at 1 to 1.5 cm;

[0010] 5) Water management: Water management should be carried out by raising seedlings in shallow water and alternating between dry and wet conditions;

[0011] 6) Fertilization management: When the tobacco seedlings grow to the cross stage, add the special fertilizer for cigar seedlings for the first time, and add the special fertilizer for cigar seedlings for the second time after the first leaf cutting. The pure nitrogen concentration of each fertilizer addition is 100-150 mg / kg water. Each time fertilization is applied, the fertilizer is dissolved and then evenly applied to the water in the seedling pool;

[0012] 7) Temperature and humidity management: After sowing, a thermometer and hygrometer are hung in the seedling shed to monitor the temperature and humidity changes in the shed in real time during the seedling raising period. The temperature and humidity in the shed are regulated by covering it with a sunshade net and ventilating the shed on all sides;

[0013] 8) Thinning and leaf cutting: When the tobacco seedlings grow to 3-4 true leaves, thin and supplement the seedlings. When thinning, leave one healthy tobacco seedling in each hole, pull out the extra tobacco seedlings, and transplant them into the holes without tobacco seedlings to ensure that the whole tray of tobacco seedlings is uniform. The first leaf cutting is done when the leaves of the tobacco seedlings just cover the surface of the seedling tray, and then the leaf cutting is done twice according to the growth situation;

[0014] 9) Hardening of seedlings: 10-15 days before transplanting tobacco seedlings, the main method is to stop fertilizer and control water, and strengthen the ventilation of the seedling shed to harden the seedlings;

[0015] 10) Disease prevention and control.

[0016] Preferably, the moist seedling raising substrate is formed by uniformly mixing 6 to 8 parts of commercial floating seedling raising substrate and 2 to 3 parts of sterilized fine soil in a volume ratio.

[0017] Preferably, when sowing, use a bamboo stick to lightly draw lines along the holes of the seedling tray, leaving a 1-2 mm deep groove on the matrix of each hole, and then put 1-2 coated seeds in each groove, and then scrape the matrix on the seedling tray flat, so that the seeds are exposed.

[0018] Preferably, in water management, the water depth at the bottom of the pond is 1-1.5 cm from the time the seedling trays are placed in the pond until the tobacco seedlings grow to 5 true leaves; the pond water is controlled according to the principle of alternating dry and wet from the time the tobacco seedlings have 5 true leaves to the time the tobacco plants become seedlings, that is, when the water in the seedling pond evaporates naturally, water is replenished in time, and the pond water depth is 1 cm; after the seedlings become mature, intermittent water supply is mainly used, that is, starting from 10 to 15 days before transplanting, the nutrient solution in the seedling pond is drained, and water is sprayed on the tobacco seedlings intermittently, and the frequency and amount of water are gradually reduced.

[0019] Preferably, in fertilization management, the special fertilizer for cigar seedling cultivation includes the following components in parts by weight: 150 parts of monoammonium phosphate, 295 parts of ammonium nitrate phosphate, 440 parts of potassium sulfate, 15 parts of borax, and 100 parts of magnesium sulfate heptahydrate.

[0020] Preferably, in the temperature and humidity management, the seedling shed is covered with a sunshade net from sowing to the large cross stage of the tobacco seedlings, and the film around the seedling shed is kept uncovered, leaving only the insect-proof net to ensure that the temperature in the seedling shed does not exceed 30°C and the relative humidity of the air is 80-85%; after the large cross stage of the tobacco seedlings, when the growth of the tobacco seedlings after thinning and reseeding returns to normal, the sunshade net is removed, the film switches around the seedling shed are adjusted, and the temperature in the shed is maintained at 25-28°C, and the relative humidity of the air is 75-80%; in the seedling stage of tobacco seedlings, when encountering low temperature weather, the film switches around the seedling shed are adjusted, and the temperature in the shed is not lower than 25°C, and the relative humidity of the air is about 80-85%.

[0021] Preferably, in the leaf cutting operation, the first leaf cutting does not exceed 50% of the leaf area, the second leaf cutting is about 6 to 8 days after the first leaf cutting, minus 50% to 80% of the leaf area, and the third leaf cutting is about 7 to 8 days after the second leaf cutting, minus 50% to 80% of the leaf area.

[0022] Preferably, while cutting the leaves for the second time, pinch off 2 to 3 old yellow leaves at the bottom of the tobacco seedlings, and use a wooden board or bamboo strip to scrape off the roots extending out of the bottom of the tray.

[0023] Preferably, in the seedling hardening operation, the specific operation of stopping fertilizer and controlling water is to first discharge the nutrient solution in the seedling pool step by step in 2 to 3 times, and when the surface of the seedling matrix is ​​dry and white, spray water in an appropriate amount to moisten the matrix in the holes, and then repeat the above process.

[0024] Preferably, when preventing and controlling diseases, strengthen the prevention and control of anthracnose and damping-off diseases caused by high temperature in the early stage of seedling cultivation, and use 1:1:(160-200) Bordeaux liquid for prevention and control 3-7 days after the big cross stage of tobacco seedlings.

[0025] The beneficial effects of the present invention are as follows: the present invention cultivates strong seedlings through moist seedling cultivation in conjunction with improvements in supporting technologies such as seedling trays, water management, fertilization management, temperature and humidity management, and leaf cutting operations, thereby effectively overcoming the high temperature obstacle in the early stage of Hainan cigar tobacco seedling cultivation, achieving the purpose of reducing the number of thin seedlings with stems, cultivating high-quality cigar tobacco seedlings, and promoting the growth quality after transplanting.

[0026] 1. The seedling tray used in the present invention has an appropriate number of holes, which not only reduces the increase in the amount of seedling tray and seedling substrate caused by too few holes, but also avoids the weak growth of tobacco seedlings due to too many holes in the seedling tray, and achieves the purpose of cultivating strong seedlings by regulating the seedling density. In this scheme, the number of holes in the seedling tray is designed to be 70 to 100 holes. The seedling trays used in conventional moist seedling cultivation and tray seedling cultivation in other tobacco areas are plastic trays, which are generally more than 100 holes and less than 200 holes. Due to the temperature and humidity conditions during the seedling cultivation in Hainan, in order to prevent the tobacco seedlings from growing too long due to a large number of holes (high density), combined with the test and production conditions, the seedling tray used is a seedling tray with a ground number of holes, which is generally 100 holes or less. Considering that too few holes (such as 50 holes) cause the seedling cultivation to occupy land and other costs are high, the minimum is more than 70 holes. The specifications of these seedling trays are generally the same, that is, the more holes the seedling tray has, the smaller the hole volume.

[0027] 2. The present invention adopts shallow water seedling cultivation and dry-wet alternation to manage water, which greatly reduces the water used for seedling cultivation. The most important thing is that water is supplied by gradually reducing the nutrient solution in the seedling cultivation pool and alternating dry and wet in the seedling stage, which can effectively promote the healthy and developed root system. At the same time, the special fertilizer for cigar seedling cultivation used contains large, medium and trace elements, which can balance the nutrition of tobacco seedlings and improve the resistance of tobacco seedlings. Effective management of water and fertilizer can promote the cultivation of strong seedlings.

[0028] 3. The present invention realizes the change of temperature and humidity in the seedling shed by adjusting the sunshade net and the film around the seedling shed, which is simple, easy and practical. Especially in the early stage of cigar seedling cultivation, the temperature outside and in the seedling shed is high. Covering the sunshade net and uncovering the film around the seedling shed can effectively reduce the temperature and humidity in the shed, and reduce the excessive growth of tobacco seedlings and thin stems caused by high temperature; when the cigar seedlings grow to the big cross stage, the sunshade net is removed in time, and the film around the seedling shed is opened and closed according to weather changes, which can play an effective role in heat preservation and promote the growth of tobacco seedlings.

[0029] 4. The present invention implements three leaf cutting operations to quantify the leaf cutting time and degree, which can effectively control the growth of the aboveground part of the tobacco seedlings and promote the growth of the root system. In particular, when performing the second leaf cutting, the roots extending out of the bottom of the tray are scraped off, which can promote the formation of more lateral roots and adventitious roots in the holes and increase the number of tobacco seedling roots. DETAILED DESCRIPTION

[0030] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation of the present invention is described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0031] Embodiment 1:

[0032] A method for growing strong cigar seedlings at high temperature in the early stage, the method comprising:

[0033] (1) Make a nursery pool. Use shaped cement bricks to make the nursery pool. The length of the nursery pool is 7m. After the bottom of the nursery pool is leveled, a black cushioning membrane with a thickness of 0.12mm is laid on it. The membrane is compacted and fixed with bricks around it. Then put 2cm deep water in the pool. Observe whether the nutrient pool membrane is leaking and whether the pool bottom is level. If the pool bottom is uneven or the cushioning membrane is leaking, the pool bottom should be leveled and the cushioning membrane should be replaced in time.

[0034] (2) Disinfection of seedling trays. 5 days before sowing, rinse the 72-hole seedling plastic tray and soak it in 500 times 10% chlorine dioxide solution for 12 minutes. Take it out and stack it neatly. Dry it before use.

[0035] (3) Matrix loading. Place a moist seedling matrix made by mixing 7 parts of floating seedling commercial matrix and 3 parts of sterilized fine soil by volume on a flat and clean surface, add water and stir continuously to make the matrix slightly moist, so that it can be held in the hand and fall apart when touched. Then fill the holes of the seedling tray with the matrix evenly, lift the seedling tray with both hands, release your hands and let the seedling tray fall vertically to the floor, repeat twice, and finally use a wooden board to scrape off the excess matrix on the tray surface and the edge of the seedling tray.

[0036] (4) Sowing. Use a bamboo stick to gently draw lines along the holes in the seedling tray, leaving a 2mm deep groove on the substrate in each hole. Then place 1 to 2 coated seeds in each groove. Then use a bamboo stick to flatten the substrate on the seedling tray so that the seeds are exposed. After sowing, place the seedling trays in the seedling pool one by one. The water depth in the seedling pool after placing the seedling trays is kept at 1.5cm.

[0037] (5) Water management. Water management should be carried out in accordance with the shallow water seedling raising and dry-wet alternation method. From the time the seedling tray is placed in the pond until the tobacco seedlings grow to 5 true leaves, the water depth at the bottom of the pond should be 1.5 cm; from the time the tobacco seedlings have 5 true leaves until the tobacco plants are mature, the water in the pond should be controlled in accordance with the dry-wet alternation principle, that is, when the water in the seedling pond evaporates naturally, water should be replenished in time, and the depth of the pond water should be 1 cm. After the seedlings are mature, intermittent water supply is mainly adopted, that is, starting from 14 days before transplanting, the nutrient solution in the seedling pond should be drained, and water should be sprayed on the tobacco seedlings intermittently, and the frequency and amount of water should be gradually reduced.

[0038] (6) Fertilization management. When the tobacco seedlings grow to the cross stage, add the first fertilizer for cigar seedlings, which consists of 150 parts of monoammonium phosphate, 295 parts of ammonium nitrate phosphate, 440 parts of potassium sulfate, 15 parts of borax, and 100 parts of magnesium sulfate heptahydrate. The pure nitrogen concentration when adding fertilizer is 100 mg / kg water; after the first leaf cutting, add the second fertilizer for cigar seedlings. The pure nitrogen concentration when adding fertilizer is 150 mg / kg water. Each time you apply fertilizer, dissolve the fertilizer and evenly apply it into the water of the seedling pool.

[0039] (7) Temperature and humidity management. After sowing, hang a thermometer and hygrometer in the seedling shed to monitor the temperature and humidity changes in the shed in real time during the seedling raising period. Cover the shed with a sunshade net and ventilate the shed to control the temperature and humidity. From sowing to the large cross stage of tobacco seedlings, cover the seedling shed with a sunshade net with a shading rate of 70%. At the same time, keep the film around the seedling shed uncovered, leaving only the 40-mesh insect-proof net, and ensure that the temperature in the seedling shed is 29°C and the relative humidity of the air is 84%. After the large cross stage of tobacco seedlings, when the growth of the tobacco seedlings after thinning and replanting returns to normal, remove the sunshade net and adjust the film switches around the seedling shed to keep the temperature in the shed at 27°C and the relative humidity of the air at 80%. In the seedling stage of tobacco seedlings, when the weather is cold, adjust the film switches around the seedling shed to keep the temperature in the shed at 25°C and the relative humidity of the air at 84%.

[0040] (8) Thinning and leaf cutting. When the tobacco seedlings grow to 3 true leaves, thin out and replant them. When thinning, leave one healthy tobacco seedling in each hole, pull out the extra tobacco seedlings and transplant them into the holes without tobacco seedlings to ensure that the tobacco seedlings are uniform throughout the tray. The first leaf cutting is done when the leaves of the tobacco seedlings just cover the surface of the seedling tray, subtracting 40% of the leaf area. The second leaf cutting is done 7 days after the first leaf cutting, subtracting 80% of the leaf area. At the same time, pinch off the two old yellow leaves at the bottom of the tobacco seedlings, and use a wooden board or bamboo piece to scrape off the roots extending from the bottom of the tray. The third leaf cutting is done 8 days after the second leaf cutting, subtracting 80% of the leaf area.

[0041] (9) Hardening the seedlings. Starting 14 days before transplanting the tobacco seedlings, the seedling hardening should be carried out by stopping fertilizer and controlling water, combined with strengthening ventilation in the seedling shed. When stopping fertilizer and controlling water, the nutrient solution in the seedling pool should be gradually discharged in two times. When the surface of the seedling substrate is dry and white, spray water to moisten the substrate in the holes, and then repeat the above process.

[0042] (10) Disease control. Strengthen the control of diseases such as anthracnose and damping-off caused by high temperatures in the early stage of seedling cultivation, and use 1:1:160 Bordeaux liquid for control 5 days after the tobacco seedlings reach the cross stage.

[0043] Compared with the floating seedling method (using conventional 162-hole foam trays and floating seedling commercial substrates at the same time and place, and performing seedling management according to the floating seedling technology), the stem circumference of the tobacco seedlings of this embodiment (stem circumference is 1.48 cm) is 0.17 cm larger than the stem circumference of the tobacco seedlings obtained by the floating seedling method (stem circumference is 1.31 cm), and the seedling index of the tobacco seedlings of this embodiment (0.131 g / plant) is 0.05 g / plant larger than the seedling index of the tobacco seedlings obtained by the floating seedling method (0.081 g / plant), and no diseases and insect pests occur.

[0044] Note: Seedling index = (stem girth / stem height + root dry weight / stem and leaf dry weight) × whole plant dry weight

[0045] Embodiment 2:

[0046] A method for growing strong cigar seedlings at high temperature in the early stage, the method comprising:

[0047] (1) The preparation of the nursery pond is the same as in Example 1.

[0048] (2) Disinfection of seedling trays. 5 days before sowing, take a rinsed 100-hole seedling plastic tray and soak it in a 500-fold diluted 10% chlorine dioxide solution for 15 minutes. Take it out and stack it neatly. Dry it before use.

[0049] (3) Matrix loading. Place a moist seedling matrix made by mixing 6 parts of floating seedling commercial matrix and 4 parts of sterilized fine soil by volume on a flat and clean surface, add water and stir continuously to make the matrix slightly moist, so that it can be held in the hand and fall apart when touched. Then fill the holes of the seedling tray with the matrix evenly, lift the seedling tray with both hands, release your hands and let the tray fall vertically to the floor, repeat 3 times, and finally use a wooden board to scrape off the excess matrix on the tray surface and the edge of the tray.

[0050] (4) Sowing. Use a bamboo stick to gently draw lines along the holes in the seedling tray, leaving a 1.5 mm deep groove on the substrate in each hole. Then place 1 to 2 coated seeds in each groove. Then use a bamboo stick to flatten the substrate on the seedling tray so that the seeds are exposed. After sowing, place the seedling trays in the seedling pool one by one. The water depth in the seedling pool after placing the seedling trays is kept at 1.5 cm.

[0051] (5) Water management. Water management should be carried out in accordance with the shallow water seedling cultivation and dry-wet alternation method. From the time the seedling tray is placed in the pond until the tobacco seedlings grow to 5 true leaves, the water depth at the bottom of the pond should be 1.5 cm; from the time the tobacco seedlings have 5 true leaves until the tobacco plants are mature, the water in the pond should be controlled in accordance with the dry-wet alternation principle, that is, when the water in the seedling pond evaporates naturally, water should be replenished in time, and the depth of the pond water should be 1 cm. After the seedlings are mature, intermittent water supply is mainly adopted, that is, starting from 15 days before transplanting, the nutrient solution in the seedling pond should be drained, and water should be sprayed on the tobacco seedlings intermittently, and the frequency and amount of water should be gradually reduced.

[0052] (6) Fertilization management. When the tobacco seedlings grow to the cross stage, add the first fertilizer for cigar seedlings, which consists of 150 parts of monoammonium phosphate, 295 parts of ammonium nitrate phosphate, 440 parts of potassium sulfate, 15 parts of borax, and 100 parts of magnesium sulfate heptahydrate. The pure nitrogen concentration when adding fertilizer is 120 mg / kg water; after the first leaf cutting, add the second fertilizer for cigar seedlings. The pure nitrogen concentration when adding fertilizer is 150 mg / kg water. Each time you apply fertilizer, dissolve the fertilizer and evenly apply it into the water of the seedling pool.

[0053] (7) Temperature and humidity management. After sowing, a thermometer and hygrometer are hung in the seedling shed to monitor the temperature and humidity changes in the shed in real time during the seedling raising period. The temperature and humidity in the shed are controlled by covering it with a shade net with a shading rate of 70% and ventilating the surrounding areas of the seedling shed. From sowing to the large cross stage of the tobacco seedlings, the shade net is covered in the seedling shed. At the same time, the film around the seedling shed is kept uncovered, and only 40 acres of insect-proof nets are retained to ensure that the temperature in the seedling shed is 29°C and the relative humidity of the air is 85%. After the large cross stage of the tobacco seedlings, when the growth of the tobacco seedlings after thinning and replanting returns to normal, the shade net is removed and the film switches around the seedling shed are adjusted to keep the temperature in the shed at 27°C and the relative humidity of the air at 78%. In the case of low temperature during the tobacco seedling growth period, the film switches around the seedling shed are adjusted to keep the temperature in the shed at 25°C and the relative humidity of the air at 85%.

[0054] (8) Thinning and leaf cutting. When the tobacco seedlings grow to 3 true leaves, thin out and replant them. When thinning, leave one healthy tobacco seedling in each hole, pull out the extra tobacco seedlings, and transplant them into the holes without tobacco seedlings to ensure that the tobacco seedlings are uniform throughout the tray. The first leaf cutting is done when the leaves of the tobacco seedlings just cover the surface of the seedling tray, subtracting 50% of the leaf area. The second leaf cutting is done 7 days after the first leaf cutting, subtracting 70% of the leaf area. At the same time, pinch off the 3 old yellow leaves at the bottom of the tobacco seedlings, and use a wooden board or bamboo piece to scrape off the roots extending from the bottom of the tray. The third leaf cutting is done about 7 days after the second leaf cutting, subtracting 75% of the leaf area.

[0055] (9) Hardening the seedlings. About 15 days before transplanting the tobacco seedlings, the seedling hardening should be carried out by stopping fertilizer and controlling water, and strengthening ventilation in the seedling shed. When stopping fertilizer and controlling water, the nutrient solution in the seedling pool should be gradually discharged in three times. When the surface of the seedling substrate is dry and white, spray water to moisten the substrate in the holes, and then repeat the above process.

[0056] (10) Disease control. Strengthen the control of diseases such as anthracnose and damping-off caused by high temperatures in the early stage of seedling cultivation, and use 1:1:160 Bordeaux liquid for control 4 days after the tobacco seedlings reach the cross stage.

[0057] Compared with the floating seedling method (using conventional 162-hole foam trays and floating seedling commercial substrates at the same time and place, and performing seedling management according to the floating seedling technology), the stem circumference of the tobacco seedlings of this embodiment (stem circumference is 1.35 cm) is 0.09 cm larger than the stem circumference of the tobacco seedlings obtained by the floating seedling method (stem circumference is 1.26 cm), and the seedling index of the tobacco seedlings of this embodiment (0.120 g / plant) is 0.038 g / plant larger than the seedling index of the tobacco seedlings obtained by the floating seedling method (0.082 g / plant), and no diseases and insect pests occur.

[0058] Note: Seedling index = (stem girth / stem height + root dry weight / stem and leaf dry weight) × whole plant dry weight

[0059] Embodiment 3:

[0060] A method for growing strong cigar seedlings at high temperature in the early stage, the method comprising:

[0061] (1) Make a nursery pool. Use steel pipes and other materials to make the nursery pool. The length of the nursery pool is 8m and the bottom of the nursery pool is flat. After the pool bottom is made level, lay a black cushioning membrane with a thickness of 0.12mm. Use bricks to compact and fix the membrane around it. Then put 1.5cm deep water in the pool. Observe whether the nutrient pool membrane is leaking and whether the pool bottom is level. If the pool bottom is uneven or the cushioning membrane is leaking, level the pool bottom and replace the cushioning membrane in time.

[0062] (2) Disinfection of seedling trays. 5 days before sowing, rinse the 72-hole seedling plastic trays and soak them in 500 times 10% chlorine dioxide solution for 15 minutes. Take them out and stack them neatly. Dry them before use.

[0063] (3) Matrix loading. Place a moist seedling matrix made by mixing 6 parts of floating seedling commercial matrix and 4 parts of sterilized fine soil by volume on a flat and clean surface, add water and stir continuously to make the matrix slightly moist, so that it can be held in the hand and fall apart when touched. Then fill the holes of the seedling tray with the matrix evenly, lift the seedling tray with both hands, release your hands and let the tray fall vertically to the floor, repeat 3 times, and finally use a wooden board to scrape off the excess matrix on the tray surface and the edge of the tray.

[0064] (4) Sowing. Use a bamboo stick to gently draw lines along the holes in the seedling tray, leaving a 2mm deep groove on the substrate in each hole. Then place 1 to 2 coated seeds in each groove. Then use a bamboo stick to flatten the substrate on the seedling tray so that the seeds are exposed. After sowing, place the seedling trays in the seedling pool one by one. The water depth in the seedling pool after placing the seedling trays is kept at 1.0cm.

[0065] (5) Water management. Water management should be carried out in accordance with the shallow water seedling raising and dry-wet alternation method. From the time the seedling tray is placed in the pond until the tobacco seedlings grow to 5 true leaves, the water depth at the bottom of the pond should be 1 cm; from the time the tobacco seedlings have 5 true leaves until the tobacco plants are mature, the water in the pond should be controlled in accordance with the dry-wet alternation principle, that is, when the water in the seedling pond evaporates naturally, water should be replenished in time, and the depth of the pond water should be 1 cm. After the seedlings are mature, intermittent water supply is mainly adopted, that is, starting from 12 days before transplanting, the nutrient solution in the seedling pond should be drained, and water should be sprayed on the tobacco seedlings intermittently, and the frequency and amount of water should be gradually reduced.

[0066] (6) Fertilization management. When the tobacco seedlings grow to the cross stage, add the first fertilizer for cigar seedlings, which consists of 150 parts of monoammonium phosphate, 295 parts of ammonium nitrate phosphate, 440 parts of potassium sulfate, 15 parts of borax, and 100 parts of magnesium sulfate heptahydrate. The pure nitrogen concentration when adding fertilizer is 100 mg / kg water; after the first leaf cutting, add the second fertilizer for cigar seedlings. The pure nitrogen concentration when adding fertilizer is 120 mg / kg water. Each time you apply fertilizer, dissolve the fertilizer and evenly apply it into the water of the seedling pool.

[0067] (7) Temperature and humidity management. After sowing, a thermometer and hygrometer are hung in the seedling shed to monitor the temperature and humidity changes in the shed in real time during the seedling raising period. The temperature and humidity in the shed are controlled by covering it with a shade net with a shading rate of 70% and ventilating the surrounding areas of the seedling shed. From sowing to the large cross stage of the tobacco seedlings, the shade net is covered in the seedling shed. At the same time, the film around the seedling shed is kept uncovered, and only the 40-mesh insect-proof net is retained to ensure that the temperature in the seedling shed is 28°C and the relative humidity of the air is 82%. After the large cross stage of the tobacco seedlings, when the growth of the tobacco seedlings after thinning and replanting returns to normal, the shade net is removed and the film switches around the seedling shed are adjusted to keep the temperature in the shed at 26°C and the relative humidity of the air at 80%. In the case of low temperature during the tobacco seedling growth stage, the film switches around the seedling shed are adjusted to keep the temperature in the shed at 25°C and the relative humidity of the air at 84%.

[0068] (8) Thinning and leaf cutting. When the tobacco seedlings grow to 3 true leaves, thin out and replant them. When thinning, leave one healthy tobacco seedling in each hole, pull out the extra tobacco seedlings, and transplant them into the holes without tobacco seedlings to ensure that the tobacco seedlings are uniform throughout the tray. The first leaf cutting is done when the leaves of the tobacco seedlings just cover the surface of the seedling tray, subtracting 50% of the leaf area. The second leaf cutting is done 8 days after the first leaf cutting, subtracting 70% of the leaf area. At the same time, pinch off the two old yellow leaves at the bottom of the tobacco seedlings, and use a wooden board or bamboo piece to scrape off the roots extending from the bottom of the tray. The third leaf cutting is done about 7 days after the second leaf cutting, subtracting 70% of the leaf area.

[0069] (9) Hardening the seedlings. About 12 days before transplanting the tobacco seedlings, the seedling hardening should be carried out by stopping fertilizer and controlling water, combined with strengthening ventilation in the seedling shed. When stopping fertilizer and controlling water, the nutrient solution in the seedling pool should be gradually discharged in three times. When the surface of the seedling substrate is dry and white, spray water to moisten the substrate in the holes, and then repeat the above process.

[0070] (10) Disease control. Strengthen the control of diseases such as anthracnose and damping-off caused by high temperatures in the early stage of seedling cultivation, and use 1:1:200 Bordeaux liquid for control 5 days after the tobacco seedlings reach the cross stage.

[0071] Compared with the tray seedling raising method (using conventional 72-hole plastic trays and floating seedling commercial substrates at the same time and place, and managing according to the tray seedling raising technology), the stem circumference of the tobacco seedlings of this embodiment (stem circumference is 1.42 cm) is 0.08 cm larger than the stem circumference of the tobacco seedlings obtained by the tray seedling raising method (stem circumference is 1.34 cm), and the seedling index of the tobacco seedlings of this embodiment (0.124 g / plant) is 0.041 g / plant larger than the seedling index of the tobacco seedlings obtained by the tray seedling raising method (0.083 g / plant), and no diseases and insect pests occur.

[0072] Note: Seedling index = (stem girth / stem height + root dry weight / stem and leaf dry weight) × whole plant dry weight

[0073] Test example:

[0074] At the cigar tobacco planting base in Wuzhishan City, Hainan Province, the seedling raising effects of the present invention (using Example 1) and the tray seedling raising method (using conventional 72-hole plastic trays and the same floating seedling raising commercial substrate, managed according to the tray seedling raising technology) and the floating seedling raising method (using 78-hole foam trays and the same floating seedling raising commercial substrate, and managing seedling raising according to the floating seedling raising technology) were compared. The seedling raising situation of the present invention is significantly better than the other two seedling raising methods, as shown by the increase in the stem girth and root dry weight of the tobacco seedlings, the improvement in the seedling index, and the robustness of the tobacco seedlings. See the table below for details.

[0075]

[0076] Note: Seedling index = (stem girth / stem height + root dry weight / stem and leaf dry weight) × whole plant dry weight

[0077] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for growing strong cigar seedlings at high temperature in the early stage, characterized in that: The method comprises: 1) Make a nursery pond; 2) Seedling tray disinfection: The number of holes in the seedling tray is 70 to 100, and the seedling tray should be disinfected before sowing; 3) Substrate tray: add water to the moistened substrate and stir continuously to make the substrate slightly moist, so that it can be held in a ball and fall apart when touched. Then fill the holes of the seedling tray with the substrate evenly. Lift the seedling tray with both hands, release both hands and let the tray fall vertically. Repeat 2-3 times. Finally, scrape off the excess substrate on the tray surface and the edge of the tray. The moistened substrate is made by evenly mixing 6-8 parts of floating seedling commercial substrate and 2-3 parts of sterilized fine soil by volume. 4) Sowing: Plant the seeds into the hole matrix. After sowing, place the seedling trays into the seedling pool in turn. The water depth of the seedling pool after placing the seedling trays is maintained at 1-1.5 cm; 5) Water management: Water management is carried out in accordance with the shallow water seedling raising and dry-wet alternation method. In water management, from the time the seedling tray is placed in the pond until the tobacco seedling grows to 5 true leaves, the water depth at the bottom of the pond is 1 to 1.5 cm; from the time the tobacco seedlings have 5 true leaves to the time the tobacco plants become seedlings, the pond water is controlled in accordance with the dry-wet alternation principle, that is, when the water in the seedling pond evaporates naturally, water is replenished in time, and the pond water depth is 1 cm; after the seedlings become seedlings, intermittent water supply is mainly used, that is, starting from 10 to 15 days before transplanting, the nutrient solution in the seedling pond is drained, and water is sprayed on the tobacco seedlings in an intermittent manner, and the frequency and amount of water are gradually reduced; 6) Fertilization management: When the tobacco seedlings grow to the cross stage, add the special fertilizer for cigar seedlings for the first time, and add the special fertilizer for cigar seedlings for the second time after the first leaf cutting. The pure nitrogen concentration of each fertilizer addition is 100-150 mg / kg water. Each time the fertilizer is applied, the fertilizer is dissolved and then evenly applied to the water in the seedling pool. In the fertilization management, the special fertilizer for cigar seedlings includes the following components in parts by weight: 150 parts of monoammonium phosphate, 295 parts of ammonium nitrate phosphate, 440 parts of potassium sulfate, 15 parts of borax, and 100 parts of magnesium sulfate heptahydrate; 7) Temperature and humidity management: After sowing, a thermometer and hygrometer are hung in the seedling shed to monitor the temperature and humidity changes in the seedling shed in real time during the seedling raising period. The temperature and humidity in the shed are controlled by covering the sunshade net and ventilating the surrounding areas of the seedling shed. In the temperature and humidity management, the sunshade net is covered in the seedling shed from sowing to the large cross stage of the tobacco seedlings. At the same time, the film around the seedling shed is kept uncovered, and only the insect-proof net is retained to ensure that the temperature in the seedling shed does not exceed 30°C and the relative humidity of the air is 80-85%. After the large cross stage of the tobacco seedlings, when the growth of the tobacco seedlings after thinning and supplementing returns to normal, the sunshade net is removed and the film switches around the seedling shed are adjusted to keep the temperature in the shed at 25-28°C and the relative humidity of the air at 75-80%. In the seedling stage of tobacco seedlings, when the weather is cold, the film switches around the seedling shed are adjusted to keep the temperature in the shed not lower than 25°C and the relative humidity of the air at 80-85%. 8) Thinning and leaf cutting: When the tobacco seedlings grow to 3-4 true leaves, it is time to thin and supplement the seedlings. When thinning, leave one healthy tobacco seedling in each hole, pull out the extra tobacco seedlings, and transplant them into the holes without tobacco seedlings to ensure that the whole tray of tobacco seedlings is uniform; the first leaf cutting is done when the leaves of the tobacco seedlings are just covered by the seedling tray, and then the leaves are cut twice according to the growth conditions. During the leaf cutting operation, the degree of leaf cutting for the first time shall not exceed 50% of the leaf area. The second leaf cutting shall be done 6-8 days after the first leaf cutting, and 50%-80% of the leaf area shall be reduced. The third leaf cutting shall be done 7-8 days after the second leaf cutting, and 50%-80% of the leaf area shall be reduced. At the same time as the second leaf cutting, pinch off 2-3 old yellow leaves at the bottom of the tobacco seedlings, and scrape off the roots extending from the bottom of the tray with a wooden board or bamboo strip; 9) Hardening of seedlings: 10-15 days before transplanting tobacco seedlings, mainly stop fertilizer and control water, and strengthen ventilation in the seedling shed to harden the seedlings; 10) Disease prevention and control.

2. The seedling raising method according to claim 1, characterized in that: When sowing, use a bamboo stick to lightly draw lines along the holes in the seedling tray, leaving a 1-2 mm deep groove on the substrate of each hole. Then put 1-2 coated seeds in each groove, and then scrape the substrate on the seedling tray flat so that the seeds are almost exposed.

3. The seedling raising method according to claim 1, characterized in that: In the seedling hardening operation, the specific operation of stopping fertilizer and controlling water is to first discharge the nutrient solution in the seedling pool step by step in 2 to 3 times, and when the surface of the seedling matrix is ​​dry and white, spray water in an appropriate amount to moisten the matrix in the holes, and then repeat the above process.

4. The seedling raising method according to claim 1, characterized in that: In disease prevention and control, strengthen the prevention and control of anthracnose and damping-off caused by high temperature in the early stage of seedling cultivation, and use 1:1: (160-200) Bordeaux liquid for prevention and control 3 to 7 days after the big cross stage of tobacco seedlings.

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