A method for applying medium and trace nutrient elements in a hydroponic system for cigar wrappers

Abstract

The invention discloses a method for applying medium and trace nutrient elements for a hydroponic system of cigar wrappers, and belongs to the technical field of tobacco agricultural production. The application method comprises the following steps: providing a nutrient solution cultivation system and medium and trace element nutrient solution for facility planting of cigar wrappers; in cigar wrapper cultivation, applying medium and trace element nutrient solution, wherein the medium and trace element nutrient solution is a nutrient solution comprising a modulating component, 65-420 μg / L of boric acid, and 230-1600 μg / L of manganese salt, and the modulating component includes at least two of 310-690 mg / L of calcium salt, 400-1300 mg / L of magnesium salt, and 40-250 mg / L of iron salt. The present invention can significantly improve the cigar wrapper output rate, improve the appearance quality of cigar wrappers, and enhance the tension of tobacco leaves by respectively applying nutrient solution of specific components in the clustering period, vigorous period, and mature period of cigar wrapper cultivation, thereby greatly improving the industrial availability of cigar wrapper raw materials.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco agricultural production, and particularly relates to a method for applying medium and trace nutrient elements for a cigar wrapper hydroponic system. Background Art

[0002] The key quality indicators of cigar wrappers used in industry usually require thinner leaves, thin and straight veins, flat leaf surface, and strong tensile strength. In particular, the tensile strength index is crucial. It is the core quantitative index for judging the toughness of tobacco leaves, that is, the tension of leaves during rolling. This index directly determines the industrial availability of cigar wrapper tobacco raw materials. However, it is not easy to produce cigar wrapper raw materials to meet such quality requirements, mainly because high-quality cigar wrappers have high requirements for ecological conditions and comprehensive production supporting technologies. At present, most of the world's high-quality cigar wrappers are planted in warm and humid places with soft sunshine; research has also shown that high-quality cigar wrappers have strict requirements on ecological factors such as nutrients, light, and temperature. Nutrient management is an important basic measure to improve product quality in plant production technology, and it is also an important topic in the current research and development of cigar wrapper tobacco production technology. At this stage, nutrient management research is mainly based on field management. The background clarity of nutrient stocks and variables and the controllability of nutrient management goals are all affected by many uncontrollable factors.

[0003] Since facilities such as greenhouses or sheds can quantitatively and directionally regulate relevant growth factors, thereby forming a suitable environment that is conducive to the yield and quality of cigar wrapper tobacco leaves; therefore, in order to accelerate the technological breakthrough of cigar wrapper production, based on the current economic value advantages of cigar wrapper tobacco leaves, facility cultivation can be used as an important technical implementation model.

[0004] However, in the existing facility-based cultivation process of cigar wrapper, there is still insufficient nutrient management, resulting in problems such as poor cigar wrapper yield and tobacco leaf tensile strength. Summary of the invention

[0005] The purpose of the present invention is to provide a method for applying medium and trace nutrients to a cigar wrapper hydroponic system, which is used to solve the problems of insufficient nutrient management in the existing facility-based cultivation of cigar wrappers, resulting in poor cigar wrapper output and tobacco leaf tensile strength.

[0006] In order to solve the above technical problems, the present invention provides a method for applying medium and trace nutrients to a hydroponic system for citrus peels, comprising the following steps: providing a nutrient solution cultivation system for facility planting of citrus peels and a medium and trace element nutrient solution; applying the medium and trace element nutrient solution during citrus peel cultivation; wherein the medium and trace element nutrient solution is a nutrient solution comprising a modulating component, 65-420 μg / L of boric acid, and 230-1600 μg / L of a manganese salt, and the modulating component includes at least two of 310-690 mg / L of a calcium salt, 400-1300 mg / L of a magnesium salt, and 40-250 mg / L of an iron salt.

[0007] In the application method provided by the present invention, a facility-based nutrient solution cultivation system (greenhouse or plastic steel greenhouse) for wrapper tobacco leaf cultivation is first built, and nutrient solution is used for water and fertilizer supply. The cultivation matrix is ​​at least one of peat, perlite or vermiculite, and the tobacco seedling planting specifications are row spacing of 1.0±0.2m and plant spacing of 0.4±0.1m. By applying medium and trace element nutrient solution in wrapper cultivation, the wrapper output rate and leaf pulling force can be improved.

[0008] It should be noted that the medium and trace element nutrient solution also includes other elements suitable for cigar wrapper cultivation, which can be added according to the actual cultivation process, or adaptively added according to the general formula nutrient solution for cigar wrapper cultivation.

[0009] In some embodiments, the medium and trace element nutrient solution includes a first medium and trace element starting nutrient solution, a second medium and trace element starting nutrient solution, and a third medium and trace element starting nutrient solution; wherein the first medium and trace element starting nutrient solution is a calcium salt containing 310-460 mg / L (for example, 310 mg / L, 340 mg / L, 370 mg / L, 385 mg / L, 420 mg / L, 460 mg / L or other values ​​within the range), 40-55 mg / L (for example, 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L or other values ​​within the range), and 10-20 mg / L (for example, 10-20 mg / L ... The first nutrient solution comprises 460-690 mg / L (for example, 460-690 mg / L of trace elements) of iron salt, 65-130 μg / L (for example, 65 μg / L, 75 μg / L, 90 μg / L, 110 μg / L, 130 μg / L or other values ​​within the range) of boric acid, and 230-500 μg / L (for example, 230 μg / L, 270 μg / L, 320 μg / L, 360 μg / L, 400 μg / L, 450 μg / L, 500 μg / L or other values ​​within the range) of manganese salt; the second nutrient solution comprises 460-690 mg / L (for example, 460-690 mg / L of trace elements) of iron salt, 65-130 μg / L (for example, 65 μg / L, 75 μg / L, 90 μg / L, 110 μg / L, 130 μg / L or other values ​​within the range) of boric acid, and 230-500 μg / L (for example, 230 μg / L, 270 μg / L, 320 μg / L, 360 μg / L, 460mg / L, 490mg / L, 520mg / L, 577mg / L, 600mg / L, 640mg / L, 690mg / L or other values ​​within this range) calcium salt, 400-600mg / L (for example, 400mg / L, 420mg / L, 450mg / L, 470mg / L, 500mg / L, 550mg / L, 600mg / L or other values ​​within this range) magnesium salt, 60-85mg / L (for example, 60mg / L, 65mg / L, 70mg / L, 75mg / L L, 80 mg / L, 85 mg / L or other values ​​within the range) of iron salt, 100-200 μg / L (for example, 100 μg / L, 120 μg / L, 135 μg / L, 150 μg / L, 200 μg / L or other values ​​within the range) of boric acid, 345-750 μg / L (for example, 345 μg / L, 380 μg / L, 420 μg / L, 480 μg / L, 540 μg / L, 600 μg / L, 700 μg / L, 750 μg / L or other values ​​within the range) of manganese salt;The third trace element starting nutrient solution comprises 860-1300 mg / L (for example, 860 mg / L, 900 mg / L, 950 mg / L, 1080 mg / L, 1100 mg / L, 1200 mg / L, 1300 mg / L or other values ​​within the range) of magnesium salt, 100-250 mg / L (for example, 100 mg / L, 120 mg / L, 150 mg / L, 170 mg / L, 200 mg / L, 250 mg / L or other values ​​within the range) of magnesium salt. nutrient solution containing 210-420 μg / L (e.g., 210 μg / L, 292.5 μg / L, 320 μg / L, 370 μg / L, 420 μg / L or other values ​​within the range) of boric acid, and 750-1600 μg / L (e.g., 750 μg / L, 800 μg / L, 1040 μg / L, 1200 μg / L, 1300 μg / L, 1400 μg / L, 1500 μg / L, 1600 μg / L or other values ​​within the range) of manganese salt. ;

[0010] In some embodiments, cigar wrapper cultivation includes initial transplanting to the clustering stage, the vigorous growth stage and the mature stage; in the initial transplanting to the clustering stage, the applied trace element nutrient solution includes a first trace element starting nutrient solution; in the vigorous growth stage, the applied trace element nutrient solution includes a second trace element starting nutrient solution; in the mature stage, the applied trace element nutrient solution includes a third trace element starting nutrient solution.

[0011] In the application method provided by the present invention, the inventors have found that elements such as calcium and boron are key mineral nutrient elements for the synthesis of the cell wall of the citrus wrapper, which will directly affect the final leaf tension and the thickness of the veins; elements such as iron, manganese, and magnesium have a greater impact on the morphological construction of tobacco leaves and the final leaf color uniformity and integrity. The inventors have further found that in different growth periods of citrus wrapper cultivation, the combination of specific nutrient solution formulas is conducive to improving the citrus wrapper output rate and leaf tension.

[0012] In some embodiments, the calcium salt is calcium nitrate tetrahydrate, the iron salt is ferrous sulfate heptahydrate, the magnesium salt is magnesium sulfate heptahydrate, and the manganese salt is manganese sulfate tetrahydrate.

[0013] It should be noted that the calcium salt, iron salt, magnesium salt and manganese salt mentioned above in the present invention may also be other salt types commonly used in the prior art.

[0014] In some embodiments, the initial transplanting to the clumping stage includes the early stage of initial transplanting (initial transplanting-15th day after transplanting) and the clumping stage (15th day after transplanting-30th day after transplanting); wherein, in the early stage of initial transplanting (initial transplanting), the first medium and trace element nutrient solution is applied, and in the clumping stage (15th day after transplanting), the nutrient solution is replaced once and the liquid level is restored to the original liquid level height, and the nutrient concentration of the replaced nutrient solution is 1.25 times the nutrient concentration of the first medium and trace element starting nutrient solution.

[0015] In some embodiments, the vigorous growth period includes the early vigorous growth period (30th to 40th day after transplanting), the middle vigorous growth period (40th to 48th day after transplanting), and the late vigorous growth period (48th to 55th day after transplanting); wherein, in the early vigorous growth period (30th day after transplanting), the nutrient solution is replaced once, and the liquid level is restored to the original liquid level, and the nutrient concentration of the replaced nutrient solution is the second starting nutrient solution of trace elements, and in the middle vigorous growth period (40th day after transplanting) and the late vigorous growth period (48th day after transplanting), the nutrient solution is replaced once, and the liquid level is restored to the original liquid level, and the nutrient concentration of the replaced nutrient solution is 2 times and 2.5 times the nutrient concentration of the first starting nutrient solution of trace elements, respectively.

[0016] In some embodiments, the maturity period includes the early maturity stage (55th to 62nd day after transplanting), the early to mid-maturity stage (62nd to 68th day after transplanting), the mid-maturity stage (68th to 74th day after transplanting), the mid-late maturity stage (74th to 80th day after transplanting), and the final maturity stage (80th to 86th day after transplanting); wherein, in the early maturity stage (55th day after transplanting), the nutrient solution is replaced once, and the liquid level is restored to the original liquid level height, and the nutrient concentration of the replaced nutrient solution is the third starting nutrient solution of trace elements, and in the early to mid-maturity stage (62nd day after transplanting), the mid-maturity stage (68th day after transplanting), the mid-late maturity stage (74th day after transplanting), and the final maturity stage (80th day after transplanting), the nutrient solution is replaced once, and the liquid level is restored to the original liquid level height, and the nutrient concentration of the replaced nutrient solution is 3 times, 2 times, 1 times, and 0.5 times the nutrient concentration of the first starting nutrient solution of trace elements, respectively.

[0017] In some embodiments, 6-10 days after the nutrient solution is replaced at the end of maturity (usually 86 days after transplanting), the nutrient solution is replaced with an equal amount of clean water. Thereafter, clean water is added every 6-10 days to the original liquid level, and the above steps of adding clean water are repeated until the tobacco leaves are harvested.

[0018] In some embodiments, the nutrient solution culture system adopts a deep liquid flow hydroponic mode.

[0019] In some embodiments, the nutrient solution culture system adopts a shallow liquid flow hydroponic mode.

[0020] In some embodiments, the nutrient solution cultivation system adopts an aeroponic mode.

[0021] In the present invention, the preparation of the nutrient solution comprises: firstly dissolving the macro- and medium-element reagents in water, and then adding the iron salt mother solution and the trace element mother solution to obtain the nutrient solution.

[0022] In some embodiments, the height of the upper surface of the substrate in the planting pot is higher than the liquid level of the nutrient solution (ie, the depth of the nutrient solution) by more than 3 cm to ensure the development of adventitious roots and their contact with the air above the liquid surface.

[0023] In some embodiments, during the process of replacing the nutrient solution, the collected residual nutrient solution will be collected in a nutrient solution recovery pool, and then after the actual nutrient content is tested, the relevant salts are appropriately added to make the nutrient content and ratio reach a nutrient solution that can be reused, and then it will be recycled.

[0024] In some embodiments, the cigar skin harvesting starts on the 60th to 70th day after transplanting, and the time interval between two consecutive harvests is 12 to 18 days.

[0025] In the present invention, delayed harvesting is beneficial to improving the citrus peel output rate and leaf pulling force.

[0026] In some embodiments, the process of citrus wrapper cultivation also includes a step of pest and disease control.

[0027] In some preferred embodiments, pest control can use insect nets. When diseases occur in the rhizomes, pesticides can be applied. Specifically, it can be: spraying 1000 times of highly effective chlorfenapyr for site disinfection and prevention of underground pests; and / or spraying 500 times of bolixil and metalaxyl for the prevention and treatment of rhizomes; and / or spraying 2000 times of imidacloprid for the prevention and treatment of tobacco aphids.

[0028] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention can significantly improve the output rate of citrus wrappers, improve the appearance quality of citrus wrappers, and enhance the tensile strength of tobacco leaves by applying nutrient solutions of specific components during the clustering period, vigorous growth period, and mature period of citrus wrapper cultivation, thereby greatly improving the industrial availability of citrus wrapper raw materials. In addition, the present invention can further improve the level of quality-oriented citrus wrapper tobacco facility cultivation technology through refined nutrient management. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Unless otherwise specified in the following examples and comparative examples, conventional cultivation techniques are used for the seedling raising, transplanting, planting and harvesting of cigar tobacco plants. For details, please refer to the technical content of cigar tobacco cultivation in Chapter 20, Section 5 of "Chinese Tobacco Cultivation" (Edited by Tobacco Research Institute of Chinese Academy of Agricultural Sciences, November 2005). Other experimental methods in the examples and comparative examples without specific conditions are usually carried out according to conventional conditions and conditions described in the manual, or according to conditions recommended by the manufacturer. The general equipment, materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0031] Furthermore, the terms “first”, “second”, and “third” are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0032] Example 1

[0033] The method for applying the medium and trace element nutrient solution provided in this embodiment is a facility-based planting experiment of wrapper tobacco leaves conducted in the Wuchang Greenhouse in Wuhan City, Hubei Province in 2023. The wrapper variety is CX-26.

[0034] The production facility system includes a two-layer three-dimensional cultivation rack, a nutrient solution tank, a planting pot, a culture matrix, a nutrient solution, and related accessories;

[0035] The key operation processes and requirements for transplanting, nutrient management, and harvesting of cigars in this experiment are as follows:

[0036] 1. Seedling cultivation

[0037] According to the conventional tobacco floating technical specifications, when the seedlings are about 55 days old, the quality of the seedlings reaches a stem height of 9-12cm, a straight stem ≥5mm, 4-6 functional leaves (true leaves), a well-developed root system, and a strong and uniform growth of the group.

[0038] 2. Transplanting

[0039] (1) Equipment and material requirements

[0040] Planting pot: PS material gardening planting pot, upper diameter 16cm, lower diameter 13cm, height 17.5cm, with multiple hollow circular holes with a diameter of 0.6±0.1cm at the bottom.

[0041] Culture substrate: current general peat-type substrate (a mixture of peat, perlite and vermiculite, 0.7kg / pot on a dry basis), decomposed cake fertilizer (prepared at 0.07kg / plant on a dry basis). Water the substrate appropriately to moisten it and mix it in the pot, then put it in the pot to reach 1kg / pot (including the weight of the pot).

[0042] Nutrient solution tank: Extruded board is used as the basic support of the nutrient solution tank. The clear dimensions in the tank are 17cm deep and 20cm wide. The net length of a single tank is 4.5m. The spacing between plantings is 45cm and the row spacing (i.e. the longitudinal center wheelbase of adjacent nutrient solution tanks) is 1.0m, that is, 10 cigar tobacco plants are planted in each tank. An anti-seepage film is laid in the nutrient solution tank, and a 4cm wide and 6cm high foam strip or wooden square is placed under the film to support the planting pot and leave space for the roots to stretch. In addition, each nutrient solution tank is equipped with basic accessories such as an air pump and a pump-end filter net bag for circulating and sucking the nutrient solution.

[0043] Nutrient solution cover: To prevent the nutrient solution from growing algae and bacteria due to direct sunlight, a sunlight-blocking cover needs to be added to the nutrient solution tank and placed around the outside of the planting pot.

[0044] Basic conditions of the greenhouse: clearance height of 4.5m, single span size of 8m*45m, the top of the greenhouse is a solid sun panel made of FRP material (2mm thick), with an inner shading net, an outer shading net and a spare cooling water curtain system, and an electric fan to ensure air circulation and PS material shed film that can be rolled up for ventilation on all sides.

[0045] (2) Transplantation operation

[0046] Prepare the substrate and pot it: Mix the decomposed cake fertilizer evenly into the regular seedling substrate, then pot it. The substrate should be filled levelly and should not be over-compacted. After potting, gently place the planting pot on the planting bracket.

[0047] Pour the nutrient solution: the pouring depth should be 3-4.5cm above the bottom of the custom pot.

[0048] Deep planting: When transplanting tobacco seedlings, the tobacco seedling planting pot is used as the root support, and the transplanting depth should be such that the center of the tobacco seedling leaves is basically flush with the upper surface of the culture medium.

[0049] Post-planting management: Before and after the clumping stage, bibbing is needed to supplement the substrate defects at the base of the stem caused by natural settlement. It is best to bib until the base of the stem is basically covered.

[0050] (3) Preparation of nutrient solution

[0051] According to the growth period of wrapper tobacco leaves, the concentration of medium and trace elements is dynamically supplied. The application of other element nutrient solution refers to the Hoagland low-dose formula and Aron formula. The specific supply is as follows:

[0052] From the initial transplanting to the clustering stage (30 days after transplanting), a nutrient solution with high calcium, high iron, high boron and high manganese is used. The formula of the major and medium nutrient elements in the initial nutrients of this stage (i.e. the day of transplanting) is shown in Table 1, and the formula of iron salts and trace elements is shown in Table 2. The content of each higher concentration of nutrient elements is as follows: high calcium (calculated as calcium nitrate (Ca(NO3)2·4H2O)) is 385mg / L, high iron (calculated as ferrous sulfate (FeSO4·7H2O)) is 50mg / L, high boron (calculated as boric acid (H3BO3)) is 90μg / L, high manganese (calculated as manganese sulfate (MnSO4·4H2 The content of other macroelements, medium elements and trace elements is shown in Tables 1 and 2. The nutrient solution was replaced around 15 days and 30 days after transplanting, and the liquid level was restored to the original level. The nutrient concentrations of the replaced nutrient solution were prepared at 1.25 times and 1.5 times the initial nutrient concentrations of transplanting. Among them, the magnesium content (calculated as magnesium sulfate (MgSO4·7H2O)) in the nutrient solution replaced around 30 days was 500 mg / L.

[0053] During the vigorous growth period (about 30 days to 55 days after transplanting), a nutrient solution with high calcium, high magnesium, high iron, high boron and high manganese is used. The formula of the major and medium-sized nutrient elements in the initial nutrients of the vigorous growth period (i.e. about 30 days after transplanting) is shown in Table 1, and the formula of iron salts and trace elements is shown in Table 2. The content of each higher concentration of nutrient elements is as follows: high calcium (calculated as calcium nitrate (Ca(NO3)2·4H2O)) is 577.5mg / L, high magnesium (calculated as magnesium sulfate (MgSO4·7H2O)) is 500mg / L, high iron (calculated as ferrous sulfate (FeSO4·7H2O)) is 75mg / L, high boron (calculated as boric acid (H3BO3)) is 135μg / L, and high manganese (calculated as manganese sulfate (MnSO4·4H2O)) is 480μg / L nutrient solution, the contents of other large, medium and trace elements are shown in Tables 1 and 2; the nutrient solution is replaced once around 40 days, 48 ​​days and 55 days after transplanting, and the liquid level is restored to the original liquid level. The nutrient concentrations of the nutrient solutions replaced for these three times are respectively prepared at 2.0 times, 2.5 times and 3.25 times of the initial nutrient concentration of the initial transplanting; among them, the magnesium content (calculated as magnesium sulfate (MgSO4·7H2O)) in the nutrient solution replaced around 55 days is 1080 mg / L, and the other large and medium elements are prepared at 3.25 times of the initial nutrient concentration of the initial transplanting according to the common formula (see Comparative Example 1).

[0054] During the maturity period (around the 55th to 80th day after transplanting), a nutrient solution with high magnesium, high iron, high boron and high manganese is used. The formula of the major and medium-sized nutrient elements in the initial nutrients of the maturity period (i.e. around the 55th day after transplanting) is shown in Table 1, and the formula of iron salts and trace elements is shown in Table 2. The content of each higher concentration of nutrient elements is as follows: high magnesium (calculated as magnesium sulfate (MgSO4·7H2O)) is 1080mg / L, high iron (calculated as ferrous sulfate (FeSO4·7H2O)) is 162.5mg / L, high boron (calculated as boric acid (H3BO3)) is 292.5μg / L, and high manganese (calculated as manganese sulfate (MnSO4·4H2O)) is 1040μg / L nutrient solution; around the 62nd, 68th, and 80th day after transplanting, the nutrient solution with high magnesium, high iron, high boron, high manganese, and high manganese (calculated as manganese sulfate (MnSO4·4H2O)) is 1040μg / L. The nutrient solution was replaced once on the 74th day and the 80th day, and the liquid level was restored to the original liquid level. The nutrient concentrations of the nutrient solutions replaced for the four times were prepared at 3 times, 2 times, 1 times, and 0.5 times the initial nutrient concentration of the initial transplantation; wherein, the nutrient concentrations of the nutrient solutions replaced for the four times were prepared according to the following scheme: magnesium (magnesium sulfate (MgSO4·7H2O)) and various trace elements were prepared at 3 times, 2 times, 1 times, and 0.5 times the initial nutrient concentration of the initial transplantation, and other large and medium elements were prepared at 3 times, 2 times, 1 times, and 0.5 times the initial nutrient concentration of the initial transplantation according to the common formula (see comparative example 1). After the last nutrient solution supplement was completed on the 80th day, the nutrient solution was completely emptied and replaced with an equal amount of clean water from the 86th day, and clean water was added every 6-10 days thereafter to the original liquid level until the tobacco leaves were harvested.

[0055] Table 1 Formulas of nutrient solutions for major and medium elements in different growth stages of wrapper tobacco leaves in the example

[0056]

[0057] Table 2 Formulas of iron salt and trace element nutrient solution for wrapper tobacco leaves at different growth stages in the example

[0058]

[0059] Note: For easy operation, iron salt and trace elements are first prepared into 400-fold and 1000-fold concentrated mother solutions, respectively, and then diluted and applied according to the multiples. The pH value of the iron salt mother solution is always maintained at around 5.5.

[0060] Requirements for each nutrient solution infusion: The nutrient solution liquid level requirement is to keep the upper surface of the substrate in the planting pot more than 3 cm above the nutrient solution liquid level to ensure the development of adventitious roots and their contact with the air above the liquid surface.

[0061] (4) Control of cultivation environment factors within the production facility system

[0062] Temperature and humidity control: Maintain the air temperature in the facility at 25±5℃ and the relative humidity at 75%±10%; when the air temperature in the facility exceeds 35℃ and the relative humidity exceeds 85%, timely use ventilation and window opening to achieve cooling and dehumidification.

[0063] Pest and disease control: give priority to the use of insect-proof nets. In principle, no pesticides will be applied unless there are root and rhizome diseases. The main pesticides used in the process are spraying 1000 times diluted high-efficiency chlorflucythrinate for site disinfection and prevention of underground pests, spraying 500 times diluted bolikat and metalaxyl to prevent and control root and rhizome diseases, and using 2000 times diluted imidacloprid to control tobacco aphids.

[0064] Tobacco plant stability guarantee: The tobacco plant stems are fixed with a single line for each plant or double lines for a single row.

[0065] (5) Topping and leaving leaves and harvesting when mature

[0066] Topping and retaining leaves: Topping should be done during the initial flowering period, and 19 effective leaves should be retained. Apply a general tobacco bud inhibitor on the same day after topping.

[0067] Harvesting at maturity: Start harvesting the lower leaves (containing the foot leaves with economic value) on the 65th day after transplanting. The interval between two subsequent harvests is 12-18 days, that is, the five harvests are separated by 12 days, 14 days, 16 days, and 18 days respectively.

[0068] Comparative Example 1

[0069] The only difference between the production method of the citrus wrapper provided in this comparative example and that in Example 1 is the different formula of the culture solution. The nutrient solution in this comparative example adopts the common formula of tobacco hydroponics, i.e., the calcium, magnesium, iron, boron and manganese concentrations recommended by the Hogland low-dose formula and the Arnon universal main formula. The formula of the major and medium nutrient elements at the starting point of each growth period of the citrus wrapper is shown in Table 3, and the formula of the iron salt and trace elements is shown in Table 4. The dosage of other nutrient solution components and process management measures are the same as those in Example 1. That is, the nutrient management during the initial transplanting-clumping period is carried out according to the following plan: the nutrient solution is replaced once around 15 days and 30 days after transplanting, and the liquid level is restored to the original liquid level. The nutrient concentrations of the replaced nutrient solutions are prepared at 1.25 times and 1.5 times the initial nutrient concentrations of the initial transplanting; the nutrient management during the vigorous growth period is carried out according to the following plan: the nutrient solution is replaced once around 40 days, 48 ​​days, and 55 days after transplanting, and the liquid level is restored to the original liquid level. The nutrient concentrations of the replaced nutrient solutions are prepared at 2 times and 1.5 times the initial nutrient concentrations of the initial transplanting. .0 times, 2.5 times, and 3.25 times; the nutrient management during the maturity period is carried out according to the following plan, the nutrient solution is replaced once around 62d, 68d, 74d, and 80d after transplanting, and the liquid level is restored to the original liquid level. The nutrient concentrations of the nutrient solutions replaced these four times are respectively prepared at 3 times, 2 times, 1 times, and 0.5 times the initial nutrient concentration of the initial transplanting; after the last nutrient solution replenishment around 80d, the fertilizer weaning operation begins, and thereafter only clean water is added every 7d to the original liquid level until the tobacco leaves are harvested.

[0070] Table 3 Formulas of nutrient solutions for major and medium elements in different growth stages of wrapper tobacco leaves in the comparative example

[0071]

[0072] Table 4 Formulas of iron salt and trace element nutrient solution for tobacco wrapper in comparative example at different growth stages

[0073]

[0074] Note: For easy operation, iron salt and trace elements are first prepared into 400-fold and 1000-fold concentrated mother solutions, respectively, and then diluted and applied according to the multiples. The pH value of the iron salt mother solution is always maintained at around 5.5.

[0075] Comparative Example 2

[0076] The only difference between the eggplant peel production method provided in this comparative example and Example 1 is the formula of the culture solution. The nutrient solution of this comparative example only uses the nutrient solution formula of high calcium, high iron, high boron and high manganese in the initial nutrient concentration during the initial transplanting-aggregation period (30 days after transplanting) during the entire growth process, and no other elements are added during the vigorous growth period and the mature period. The dosage of other nutrient solution components and process management measures (including fertilizer suspension operation) are the same as those in Example 1.

[0077] Comparative Example 3

[0078] The only difference between the aubergine production method provided in this comparative example and Example 1 is the formula of the culture solution. The nutrient solution of this comparative example only uses the nutrient solution formula of high calcium, high magnesium, high iron, high boron and high manganese at the initial nutrient concentration during the vigorous growth period (about 30 days to about 55 days after transplanting) during the entire growth process, and no other elements are added during the initial transplanting-aggregation period and maturity period. The dosage of other nutrient solution components and process management measures (including fertilizer suspension operation) are the same as those in Example 1.

[0079] Comparative Example 4

[0080] The only difference between the aubergine production method provided in this comparative example and Example 1 is the formula of the culture solution. The nutrient solution of this comparative example only uses the nutrient solution formula of high magnesium, high iron, high boron and high manganese at the initial nutrient concentration of the maturity period (about 55 days to about 80 days after transplanting) during the entire growth process, and no other elements are added during the initial transplanting-aggregation period and the vigorous growth period. The dosage of other nutrient solution components and process management measures (including fertilizer suspension operation) are the same as those in Example 1.

[0081] Wrapper Performance Test

[0082] The cigar wrapper yield and appearance quality were tested according to the method specified in Hubei Provincial Standard "Cigar Tobacco Grade Quality Specification" DB 42 / T 1549-2020; the tobacco leaf tensile strength was measured using an M250-2.5 CT tensile testing machine (produced by KARL, Germany). The results are shown in Table 5 below:

[0083] Table 5 Wrapper yield and key quality index results of wrapper tobacco leaves

[0084]

[0085] From the results in Table 5, it can be seen that by comparing the inspection indicators of Example 1 and Comparative Example 1, it can be found that compared with Comparative Example 1, the cigar wrapper output rate of the new method for applying medium and trace elements provided in Example 1 of the present invention is increased by 23.46%; the leaf thickness is effectively reduced in terms of appearance quality, the reduction is up to 20.85%, the thickness of the branch veins is also significantly reduced, and the leaf surface flatness and color uniformity are significantly improved; the tobacco leaf tension is significantly improved, and the improvement is up to 58.97%. Although the three treatments of Comparative Example 2, Comparative Example 3, and Comparative Example 4 have different degrees of improvement in the appearance quality and tension of the cigar wrapper compared with Comparative Example 1, compared with Example 1, there are still significant deficiencies in indicators such as leaf thickness and tobacco leaf tension. The above results show that the use of the new method for applying medium and trace elements of the present invention can increase the cigar wrapper output rate by more than 20%, increase the cigar wrapper tension by more than 50%, and significantly improve the overall quality of tobacco leaves.

[0086] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0087] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. 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 applying medium and trace nutrients to a cigar wrapper hydroponic system, characterized in that: The steps include: Provide a nutrient solution cultivation system and medium and trace element nutrient solution for facility planting of cigar wrapper cultivation; In the cultivation of citrus wrappers, the medium and trace element nutrient solution is applied; The medium and trace element nutrient solution is a nutrient solution comprising a modulating component, 65-420 μg / L of boric acid, and 230-1600 μg / L of a manganese salt, wherein the modulating component comprises at least two of 310-690 mg / L of a calcium salt, 400-1300 mg / L of a magnesium salt, and 40-250 mg / L of an iron salt; The medium and trace element nutrient solution comprises a first medium and trace element starting nutrient solution, a second medium and trace element starting nutrient solution and a third medium and trace element starting nutrient solution; Wherein, the first trace element starting nutrient solution is a nutrient solution containing 310-460 mg / L of calcium salt, 40-55 mg / L of iron salt, 65-130 μg / L of boric acid, and 230-500 μg / L of manganese salt; The second trace element starting nutrient solution is a nutrient solution containing 460-690 mg / L of calcium salt, 400-600 mg / L of magnesium salt, 60-85 mg / L of iron salt, 100-200 μg / L of boric acid, and 345-750 μg / L of manganese salt; The third trace element starting nutrient solution is a nutrient solution containing 860-1300 mg / L of magnesium salt, 100-250 mg / L of iron salt, 210-420 μg / L of boric acid, and 750-1600 μg / L of manganese salt; The cigar peel cultivation includes the initial transplanting to the clustering stage, the vigorous growth stage and the mature stage; During the initial transplanting to the clustering stage, the medium and trace element nutrient solution applied includes the first medium and trace element starting nutrient solution; During the vigorous growth period, the medium and trace element nutrient solution applied includes the second medium and trace element starting nutrient solution; During the maturity period, the applied medium and trace element nutrient solution includes the third medium and trace element starting nutrient solution.

2. The method for applying medium and trace nutrients to the cigar wrapper hydroponic system according to claim 1, characterized in that: The calcium salt is calcium nitrate tetrahydrate, the iron salt is ferrous sulfate heptahydrate, the magnesium salt is magnesium sulfate heptahydrate, and the manganese salt is manganese sulfate tetrahydrate.

3. The method for applying medium and trace nutrients to the cigar wrapper hydroponic system according to claim 1, characterized in that: The initial transplanting to clustering stage includes the initial transplanting early stage and the clustering stage; Among them, at the initial stage of the initial transplanting, the first trace element starting nutrient solution is applied, and at the clumping stage, the nutrient solution is replaced once and the liquid level is restored to the original liquid level. The nutrient concentration of the replaced nutrient solution is 1.25 times the nutrient concentration of the first trace element starting nutrient solution.

4. The method for applying medium and trace nutrients to the cigar wrapper hydroponic system according to claim 1, characterized in that: The vigorous growth period includes the early vigorous growth period, the middle vigorous growth period and the late vigorous growth period; Among them, in the initial stage of vigorous growth, the nutrient solution is replaced once, and the liquid level is restored to the original liquid level height, and the nutrient concentration of the replaced nutrient solution is the second trace element starting nutrient solution. In the middle stage of vigorous growth and the late stage of vigorous growth, the nutrient solution is replaced once, and the liquid level is restored to the original liquid level height. The nutrient concentration of the replaced nutrient solution is 2 times and 2.5 times the nutrient concentration of the first trace element starting nutrient solution, respectively.

5. The method for applying medium and trace nutrients to the cigar wrapper hydroponic system according to claim 1, characterized in that: The maturity stage includes early maturity, early middle maturity, middle maturity, late middle maturity, and late maturity; Among them, in the early stage of maturity, the nutrient solution is replaced once, and the liquid level is restored to the original liquid level height, and the nutrient concentration of the replaced nutrient solution is the third starting nutrient solution of trace elements. In the early to middle stage of maturity, the middle stage of maturity, the late to middle stage of maturity, and the late stage of maturity, the nutrient solution is replaced once respectively, and the liquid level is restored to the original liquid level height, and the nutrient concentration of the replaced nutrient solution is 3 times, 2 times, 1 times, and 0.5 times the nutrient concentration of the first starting nutrient solution of trace elements, respectively.

6. The method for applying medium and trace nutrients to the cigar wrapper hydroponic system according to claim 5, characterized in that: 6-10 days after the nutrient solution is replaced at the end of the maturity period, the nutrient solution is replaced with an equal amount of clean water. Thereafter, clean water is added every 6-10 days to the original liquid level, and the above steps of adding clean water are repeated until the tobacco leaves are harvested.

7. The method for applying medium and trace nutrients to the cigar wrapper hydroponic system according to claim 1, characterized in that: The nutrient solution cultivation system adopts at least one of a deep liquid flow hydroponics mode, a shallow liquid flow hydroponics mode and a mist cultivation mode.

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