A method for reducing the diameter of the veins of a cigar wrapper leaf

Abstract

The present application relates to cigar tobacco planting and processing technical field, especially to a method for reducing the diameter of cigar wrapper leaf vein. It comprises the following steps: soil conditioning: adjusting the soil conditions to be: sandy loam, pH value is 5.5~7.5, organic matter content is 14~20g / kg, available potassium content is 140~190mg / kg, available phosphorus content is 30~40mg / kg, alkali hydrolysis nitrogen content is 90~110mg / kg; sowing and transplanting: sowing in the soil, transplanting after ridging; fertilizing per mu at transplanting, the fertilizing ratio is: N: P2O5: K2O = 1: (0.4~0.6): (2.2~2.7); after 25~30d of transplanting, applying 8~12kg of potassium nitrate per mu; shading treatment: shading treatment is carried out on the cigar during the growth period. In the application, by adjusting the suitable soil conditions and fertilizing conditions, the diameter of the upper and lower leaf veins of the cigar tobacco can be uniformly and significantly reduced under the shading condition, so that the cigar tobacco leaves with small and uniform overall diameter of leaf vein can be obtained, which is suitable for being used as the raw material of cigar wrapper.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cigar leaf planting and processing technology, and particularly relates to a method for reducing the diameter of cigar wrapper vein. BACKGROUND

[0002] In recent years, cigar leaves can be divided into cigar wrappers, cigar overwrappers and cigar cores according to their use in cigar products. In addition to protecting the whole cigar and enhancing the taste, cigar wrappers also play a crucial role in beautifying the appearance of the cigar, displaying individual characteristics and quality level. Cigar wrappers used in industry usually require wide and thin leaves, fine texture, fine and flat veins, and high tensile strength. Among them, the thickness of the leaf vein is closely related to the appearance of the cigar wrapper, the smoothness and uniformity of the appearance of the finished cigarette, and obtaining thinner leaf veins is the key to improving the cigar wrapper.

[0003] Studies have shown that among many ecological factors, temperature, relative humidity, light, rainfall and soil conditions have a greater impact on the quality of cigar wrappers. In terms of cultivation measures, people often use shading, low nitrogen, no topping and more irrigation to reduce the accumulation of dry matter in the cigar wrapper and improve the quality of the cigar wrapper. However, despite this, there are few reports focusing on the diameter of the cigar wrapper vein.

[0004] Journal article "Effect of Shading Cultivation on Leaf Surface Uniformity of Cigar Wrapper Tobacco Leaves" by Guo Hao et al. pointed out that in the soil type of brown loamy soil, the basic physicochemical properties are: alkali-hydrolyzable nitrogen 66.05 mg / kg, available potassium 128.30 mg / kg, available phosphorus 52.63 mg / kg, organic matter 21.17 g / kg, and pH 7.26; under the conditions of fertilizer application rate of N:P2O5:K2O=1.0:0.3:2.0, for upper leaves, the thickness of the main vein and branch vein decreases with the increase of shading degree, the main vein decreases significantly at a light transmittance of 70%, and the branch vein decreases significantly at a light transmittance of 80%; for middle leaves, whether the main vein or the branch vein, their thickness decreases slightly with the increase of shading degree, but there is no significant difference.

[0005] That is to say, the prior art scheme can reduce the diameter of the leaf veins, but the reduction degree of the upper and lower parts of the leaf veins is uneven, and the reduction degree of the upper part of the leaf veins is significantly greater than that of the middle part of the leaf veins. Generally speaking, the diameter of the upper part of the leaf veins of a cigar tobacco leaf is small, and the diameter of the middle and lower parts of the leaf veins is large. After the treatment by the prior art scheme, the diameter of the upper part of the leaf veins of the cigar tobacco leaf is smaller, but the diameter of the middle and lower parts of the leaf veins changes little. This makes the difference between the upper and lower diameters of the leaf veins of the cigar tobacco leaf further enlarged. Compared with ordinary cigar tobacco leaves, although the diameter of part of the leaf veins of the cigar tobacco leaf is reduced, the difference between the upper and lower diameters of the leaf veins is more uneven, which is more unfavorable for the application of the cigar tobacco leaf as a cigar wrapper. Therefore, there is an urgent need for a method capable of uniformly reducing the diameters of the upper and lower parts of the leaf veins of a cigar tobacco leaf. SUMMARY

[0006] The present application aims to solve the above problems and provide a method capable of uniformly reducing the diameters of the upper and lower parts of the leaf veins of a cigar wrapper.

[0007] The technical scheme for solving the problems of the present application is to provide a method for reducing the diameters of the leaf veins of a cigar wrapper, comprising the following steps:

[0008] S1. Soil conditioning: adjust the soil conditions to be: sandy loam, pH value of 5.5-7.5, organic matter content of 14-20 g / kg, available potassium content of 140-190 mg / kg, available phosphorus content of 30-40 mg / kg, and alkali-hydrolyzable nitrogen content of 90-110 mg / kg;

[0009] S2. Sowing and transplanting: sowing in the soil and transplanting after ridging; fertilizing per mu at the time of transplanting, with a fertilization ratio of N:P2O5:K2O=1:(0.4-0.6):(2.2-2.7); and applying 8-12 kg of potassium nitrate per mu after 25-30 days of transplanting;

[0010] S3. Shading treatment: shading the cigar during its growth period.

[0011] In the present application, the inventors obtain a technical solution that can uniformly and significantly reduce the diameter of the upper and lower leaf veins of cigar leaves under shading conditions through a large number of experiments. The inventors speculate that this is mainly related to the influence of soil conditions and fertilization conditions on the diameter of cigar leaves: for example, sandy loam soil is composed of a large number of sand particles and a small amount of clay, the soil particles are relatively coarse, the porosity is large, the air permeability and water permeability are good, but the water and fertilizer retention capacity is relatively poor, which may increase the leaf vein density of the plant leaves to help transport water and nutrients to various parts of the leaves more quickly, based on the limited xylem resource allocation, the overall diameter of the leaf veins will be reduced to meet the demand for leaf vein density. At the same time, the nutrient content in the sandy loam soil may be lower, but the nutrient conversion speed is faster, and based on this, the nutrient composition and subsequent fertilizer composition are adjusted. For example, the content of available potassium in the soil and the content of potassium in the fertilizer are relatively more than those of the prior art to maintain the water and nutrient transport capacity under smaller leaf vein diameter; the content of alkali-hydrolyzable nitrogen is relatively more than that of the prior art to promote leaf vein expansion and ensure the clarity of small-diameter leaf veins; the content of available phosphorus in the soil is relatively less than that of the prior art to reduce cell division and expansion during leaf germination, thereby reducing the leaf vein diameter, and the content of phosphorus in the fertilizer is relatively more than that of the prior art to ensure the growth of the leaves after germination. In addition, the soil pH is controlled to be slightly acidic to increase the solubility of the above nutrient components, improve the absorption rate of the plant to the nutrient components, and strengthen the role of the nutrient components.

[0012] In step S1, it can be understood that, since the amount of sandy loam soil is large, its pH value, organic matter content, available potassium content, available phosphorus content, and alkali-hydrolyzable nitrogen content cannot be accurately controlled at a certain fixed value. Generally, several test points are uniformly taken on the soil, each test point is detected, and the data of each test point is ensured to be within the above range.

[0013] As a preferred embodiment of the present application, the pH value of the sandy loam soil is 5.6-6.9; the pH value of the test point can be 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9; and the pH value is further preferably in the range of 6.0-6.5.

[0014] As a preferred embodiment of the present application, the organic matter content is 15-19 g / kg; the organic matter content of the test point can be 15 g / kg, 16 g / kg, 17 g / kg, 18 g / kg, or 19 g / kg; and the organic matter content is further preferably in the range of 15.08-18.89 g / kg.

[0015] As a preferred embodiment of the present application, the available potassium content is 145-180 mg / kg; the available potassium content at the test points can be 145 mg / kg, 150 mg / kg, 155 mg / kg, 160 mg / kg, 165 mg / kg, 170 mg / kg, 175 mg / kg, 180 mg / kg; the available potassium content is further preferably in the range of 146.67-179.46 mg / kg.

[0016] As a preferred embodiment of the present application, the available phosphorus content is 31-37 mg / kg; the available phosphorus content at the test points can be 31 mg / kg, 32 mg / kg, 33 mg / kg, 34 mg / kg, 35 mg / kg, 36 mg / kg, 37 mg / kg; the available phosphorus content is further preferably in the range of 31.08-36.82 mg / kg.

[0017] As a preferred embodiment of the present application, the available phosphorus content is 31-37 mg / kg; the available phosphorus content at the test points can be 31 mg / kg, 32 mg / kg, 33 mg / kg, 34 mg / kg, 35 mg / kg, 36 mg / kg, 37 mg / kg; the available phosphorus content is further preferably in the range of 31.08-36.82 mg / kg.

[0018] As a preferred embodiment of the present application, 23-26 kg of lime can also be applied per mu of soil to balance the soil pH. It can be 23 kg, 24 kg, 25 kg, 26 kg per mu; preferably 25 kg per mu.

[0019] In step S2, the sowing is not limited.

[0020] As a preferred embodiment of the present application, when ridging, the ridge spacing is kept at 1-1.2 m, such as 1 m, 1.1 m, 1.2 m, preferably 1.1 m. It is preferred to ensure that the ridge surface is flat, the ridge body is full and straight, and there is no pit and depression. By adjusting the appropriate ridge spacing, the leaves can be more stretched, the leaf area is increased, and the efficiency of the shading treatment on the leaf vein diameter is improved.

[0021] As a preferred embodiment of the present application, the row spacing is 105-115 cm, such as 105 cm, 110 cm, 115 cm; the plant spacing is 35-40 cm, such as 35 cm, 40 cm; preferably, the row spacing is 110 cm and the plant spacing is 40 cm when transplanting, and the number of transplanted plants per mu is about 1500. In the present application, the relatively larger row spacing and the relatively smaller plant spacing are used to adjust the light and ventilation of the leaves, so that the leaves grow upward and outward, and the efficiency of the shading treatment on the diameter of the leaf veins is improved.

[0022] As a preferred embodiment of the present application, the fertilization ratio is N:P2O5:K2O=1:(0.45-0.55):(2.45-2.55) per mu when transplanting, such as 1:0.45:2.55, 1:0.5:2.5, 1:0.55:2.45, and preferably 1:0.5:2.5.

[0023] As a preferred embodiment of the present application, 9-11 kg of potassium nitrate is top-dressed per mu after 25-30 days of transplanting. The time can be 25 d, 26 d, 27 d, 28 d, 29 d, 30 d, and preferably 30 d; the potassium nitrate can be 9 kg, 10 kg, 11 kg per mu, and preferably 10 kg.

[0024] As a preferred embodiment of the present application, the "well-cellar type" transplanting method is used when transplanting, and the technical procedures of "three musts, three must nots, and five appropriateness" are followed. The "three musts" are to select seedlings, to take soil, and to prevent insects; the "three must nots" are not to be too close, not to be too heavy, and not to be hidden; and the "five appropriateness" are appropriate for tobacco seedlings, appropriate for the transplanting period, appropriate for the well-cellar specifications, appropriate for the water amount, and appropriate for the sealing time.

[0025] In step S3, as a preferred embodiment of the present application, the light transmittance of the shading treatment during the growth period of the cigar is 70%-95%, such as 70%, 75%, 80%, 85%, 90%, or 95%.

[0026] The growth period of the cigar includes the rosette stage and the vigorous growth stage, and the existing technology mainly studies the influence of different light transmittances on the diameter of the leaf veins during the whole growth period. In the present application, the inventors have also found that the shading treatment with different light transmittances during different growth periods also has a significant influence on the diameter of the leaf veins: the main veins of the tobacco leaves treated with shading during the rosette stage are the thinnest, and the branch veins of the tobacco leaves treated with shading during the whole growth period are the thinnest. Since the main veins have a more significant influence on the quality of the cigar wrapper, and the diameter of the main veins is generally larger than that of the branch veins, a higher reduction degree of the main veins relative to the branch veins is beneficial to balancing the diameters of the main veins and the branch veins and improving the uniformity of the leaf veins. Therefore, in some embodiments, as a preferred embodiment of the present application, in step S3, the cigar is subjected to the shading treatment only during the rosette stage during the growth period of the cigar.

[0027] The inventors further found that the degree of influence of light transmittance on the diameter of the main vein and the branch vein is different in different growth periods. Therefore, by adjusting the light transmittance in different periods, a tobacco leaf with a main vein and a branch vein with a diameter as small as possible and a good balance between the diameters of the main vein and the branch vein can be obtained. Therefore, in some embodiments, as a preferred embodiment of the present application, during the growth of a cigar, shading treatment with a light transmittance of 75% to 80% is performed during the rosette stage, such as 75%, 76%, 77%, 78%, 79%, or 80%, and shading treatment with a light transmittance of 90% to 95% is performed during the vigorous growth stage, such as 90%, 91%, 92%, 93%, 94%, or 95%. Preferably, shading treatment with a light transmittance of 80% is performed during the rosette stage, and shading treatment with a light transmittance of 95% is performed during the vigorous growth stage.

[0028] In the prior art, people also use the method of not topping to reduce the accumulation of dry matter in the tobacco jacket and improve the quality of the tobacco jacket. The inventors found that topping has a certain influence on the diameter of the leaf vein of the cigar tobacco leaf, and appropriate topping can promote the distribution of plant nutrients and help reduce the diameter of the leaf vein of the top tobacco leaf. Therefore, as a preferred embodiment of the present application, the following step is also included: S4. Topping: When the cigar flowers open, the cigar is topped: 18 to 22 cm of leaf below the flower is retained, such as 18 cm, 19 cm, 20 cm, 21 cm, or 22 cm; the number of leaves left after topping is 16 to 20, such as 16, 17, 18, 19, or 20. Preferably, 20 cm of leaf below the flower is retained, and the number of leaves left after topping is 18.

[0029] As a preferred embodiment of the present application, when topping, a knife is used to cut an inclined surface, and the topping is performed in the morning on a sunny day.

[0030] Through the above method, the diameter of the leaf vein of the cigar tobacco leaf during the growth process can be reduced. In some embodiments, the cigar jacket is obtained after the cigar tobacco leaf is cured and fermented, and the curing and fermentation process affects the degree of removal of water from the leaf vein and also has a certain influence on the diameter of the leaf vein. Therefore, as a preferred embodiment of the present application, the following step is also included: S5. Curing: After the tobacco leaf is picked, the tobacco leaf is cured under the following conditions: the density of the cured tobacco is 90 to 110 pieces per rod, such as 90 pieces per rod, 95 pieces per rod, 100 pieces per rod, 105 pieces per rod, or 110 pieces per rod, and preferably 110 pieces per rod; the rod distance is 0.3 to 0.5 m, such as 0.3 m, 0.35 m, 0.4 m, 0.45 m, or 0.5 m, and preferably 0.4 m; the distance between the two layers is 0.8 to 1.0 m, such as 0.8 m, 0.85 m, 0.9 m, 0.95 m, or 1.0 m, and preferably 0.9 m.

[0031] As a preferred embodiment of the present invention, the modulation includes the following steps in sequence: first, at a temperature of 24~26℃, for example, 24℃, 25℃, or 26℃; relative humidity of 80%~85%, for example, 80%, 81%, 82%, 83%, 84%, or 85%; treatment for 4~5 days, for example, 4 days or 5 days; during this period, the leaves soften and wilt, and the leaf tips and edges turn yellow, which is the wilting period.

[0032] Then, at a temperature of 25~28℃ (e.g., 25℃, 26℃, 27℃, 28℃) and a relative humidity of 82%~87% (e.g., 82%, 83%, 84%, 85%, 86%, 87%), treat for 5~8 days (e.g., 5 days, 6 days, 7 days, 8 days). During this period, the green color of the tobacco leaves fades, turning yellow and softening, which is the yellowing period.

[0033] Then, at a temperature of 28~30℃ (e.g., 28℃, 29℃, 30℃) and a relative humidity of 70%~75% (e.g., 70%, 71%, 72%, 73%, 74%, 75%), treat for 5~8 days (e.g., 5 days, 6 days, 7 days, 8 days). During this period, the tobacco leaves will turn yellow and brown until the leaf tips and edges begin to dry. It is important to achieve "three basic uniformities": the color of the upper and lower surfaces of the leaves should be basically uniform, the color of the leaf tips and bases should be basically uniform, and the color of the leaf veins should be basically uniform. This is the browning stage.

[0034] Finally, the temperature is 35~38℃, for example, 35℃, 36℃, 37℃, or 38℃; the relative humidity is 40~45%, for example, 40%, 41%, 42%, 43%, 44%, or 45%; and the treatment lasts for 5~8 days, for example, 5 days, 6 days, 7 days, or 8 days. During this period, the main veins of the tobacco leaves are thoroughly dried, become sunken and black, and are easily broken; this is the drying period.

[0035] As a preferred embodiment of the present invention, the method further includes the following step: S6. Fermentation: fermenting the prepared tobacco leaves. The fermented tobacco leaves can be used as cigar wrappers.

[0036] As a preferred embodiment of the present invention, the fermentation conditions are: a temperature of 25-30°C, such as 25°C, 26°C, 27°C, 28°C, 29°C, or 30°C; a relative humidity of 70%-75%, such as 70%, 71%, 72%, 73%, 74%, or 75%; and a fermentation period of 20-25 days, such as 20 days, 21 days, 22 days, 23 days, 24 days, or 25 days. Preferably, the fermentation is carried out at a temperature of 27°C and a relative humidity of 72% for 25 days.

[0037] The beneficial effects of this invention are:

[0038] 1. In this application, the effects of soil conditions and fertilization conditions on the vein diameter of cigar tobacco leaves are utilized. By adjusting appropriate soil conditions and fertilization conditions, the upper and lower vein diameters of cigar tobacco leaves under shade conditions can be uniformly and significantly reduced, thereby obtaining cigar tobacco leaves with small and uniform overall vein diameters, which are suitable for use as cigar wrapper materials.

[0039] 2. In some embodiments, the overall vein diameter can be further reduced by adjusting the topping method and using different degrees of shading at different growth stages.

[0040] 3. Using the technical solutions of this application, not only can the thickness of the veins of cigar wrapper leaves be effectively reduced, but also the internal chemical composition of cigar wrapper leaves can be regulated, thereby comprehensively improving the appearance quality and internal quality of cigar wrapper leaves while maintaining or increasing the yield of cigar wrapper leaves in the application area. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 are pictures of tobacco leaves before conditioning and after conditioning and fermentation in Examples 1-3 and Comparative Example 1.

[0042] Figure 2 are columnar comparison charts of the main vein diameter and branch vein diameter of tobacco leaves before conditioning in Examples 1-3 and Comparative Example 1. DETAILED DESCRIPTION

[0043] The following is a specific embodiment of the present application, and the technical solutions of the present application are further described, but the present application is not limited to these embodiments.

[0044] Example 1

[0045] A method for reducing the vein diameter of cigar wrapper leaves, comprising the following steps:

[0046] S1. Soil conditioning: adjusting the soil conditions to be: sandy loam soil, pH value of 5.60-6.90, organic matter content of 15.08-18.89 g / kg, available potassium content of 146.67-179.46 mg / kg, available phosphorus content of 31.08-36.82 mg / kg, and alkali-hydrolyzable nitrogen content of 96.7-106.8 mg / kg; and applying 25 kg of lime per mu.

[0047] S2. Sowing and transplanting: selecting the test cigar variety as Chu Xue 80, sowing from February 25 to March 10 each year, and raising ridges from March 20 to March 30, with a ridge spacing of 1.1 m, a flat ridge surface, a full and straight ridge body, and no pits and depressions.

[0048] Transplanting is carried out from April 20 to April 25 each year, and the row spacing is kept at 110 cm and the plant spacing is kept at 40 cm, and the number of transplanted plants per mu is about 1500. The fertilization ratio is N:P2O5:K2O=1:0.5:2.5, and 10 kg of potassium nitrate is applied per mu after 30 days of transplanting.

[0049] S3. Shading treatment: During the whole growth period of cigar, the cigar is shaded by using a white shading net with a light transmittance of 80%.

[0050] S4. Topping: When the cigar begins to bloom, the cigar is topped, and 20 cm of leaves below the flower are reserved, and the number of leaves after topping is 18. When topping, a knife is used to cut an inclined surface, and the topping is carried out in the morning on a sunny day.

[0051] S5. Modulation: The tobacco leaves are picked from the upper part of the growing part, and the picked tobacco leaves are complete, free of pests and diseases, and the yellowing degree is 25% to 50%.

[0052] After picking the tobacco leaves, the tobacco leaves are modulated under the conditions that the density of baling tobacco is 100 pieces per rod, the rod spacing is 0.4 m, and the spacing between two layers is 0.9 m. The modulation includes the following steps in sequence: treatment for 4 days at a temperature of 25 ℃ and a relative humidity of 80%; treatment for 6 days at a temperature of 27 ℃ and a relative humidity of 80%; treatment for 6 days at a temperature of 29 ℃ and a relative humidity of 75%; and treatment for 8 days at a temperature of 37 ℃ and a relative humidity of 42%.

[0053] S6. The modulated tobacco leaves are subjected to fermentation treatment, and the fermentation conditions are as follows: fermentation for 25 days at a temperature of 27 ℃ and a relative humidity of 72%.

[0054] Example 2

[0055] This example is basically the same as example 1, and the only difference is that:

[0056] In step S3, only during the rosette stage of cigar, the cigar is shaded by using a white shading net with a light transmittance of 80%.

[0057] Example 3

[0058] In step S3, only during the vigorous growth stage of cigar, the cigar is shaded by using a white shading net with a light transmittance of 80%.

[0059] Example 4

[0060] This example is basically the same as example 1, and the only difference is that:

[0061] In step S3, a white shading net with a light transmittance of 80% is used for shading treatment during the rosette stage, and a white shading net with a light transmittance of 95% is used for shading treatment during the vigorous growth stage.

[0062] Example 5

[0063] This example is basically the same as Example 1, except that:

[0064] In Step S2, the fertilization ratio is N:P205:K20 = 1:0.6:2.4.

[0065] Example 6

[0066] This example is basically the same as Example 1, except that:

[0067] In Step S2, the fertilization ratio is N:P205:K20 = 1:0.6:2.4.

[0068] Example 7

[0069] This example is basically the same as Example 1, except that:

[0070] In Step S4, no topping is performed.

[0071] Example 8

[0072] This example is basically the same as Example 1, except that:

[0073] In Step S2, the row spacing is kept at 100 cm and the plant spacing is kept at 45 cm.

[0074] Comparative Example 1

[0075] This comparative example is basically the same as Example 1, except that:

[0076] In Step S3, no shading treatment is performed.

[0077] Comparative Example 2

[0078] This comparative example is basically the same as Example 1, except that:

[0079] In Step S1, the soil conditions are adjusted as follows: loamy soil, pH value of 5.60-6.90, organic matter content of 15.08-18.89 g / kg, available potassium content of 146.67-179.46 mg / kg, available phosphorus content of 31.08-36.82 mg / kg, and alkali-hydrolyzable nitrogen content of 96.7-106.8 mg / kg; and 25 kg of lime is applied per mu.

[0080] Comparative Example 3

[0081] This comparative example is basically the same as Example 1, except that:

[0082] In step S1, the soil conditions are adjusted as follows: sandy loam, pH value of 7-7.5, organic matter content of 20.17-23.54 g / kg, available potassium content of 115.12-138.55 mg / kg, available phosphorus content of 48.69-60.11 mg / kg, and alkaline hydrolysis nitrogen content of 52.69-74.28 mg / kg; and 25 kg of lime is applied per mu.

[0083] Comparative Example 4

[0084] This comparative example is basically the same as Example 1, except that:

[0085] In step S1, the soil conditions are adjusted as follows: loamy soil, pH value of 7-7.5, organic matter content of 20.17-23.54 g / kg, available potassium content of 115.12-138.55 mg / kg, available phosphorus content of 48.69-60.11 mg / kg, and alkaline hydrolysis nitrogen content of 52.69-74.28 mg / kg; and 25 kg of lime is applied per mu.

[0086] Leaf vein diameter detection

[0087] The pictures of the tobacco leaves obtained in Comparative Example 1 and Examples 1-3 before the tobacco veins are cured and after the cured tobacco leaves are fermented are shown in Figure 1 As can be seen from the pictures, compared with Comparative Example 1 (CK), the diameters of the tobacco veins, especially the diameters of the upper and lower parts of the main veins, are significantly reduced in Examples 1-3, indicating that the shading treatment can reduce the overall diameter of the veins under the soil conditions, fertilization conditions, and topping conditions of the present application.

[0088] Main vein diameter: the cured tobacco leaves obtained in the examples and comparative examples are evenly divided into upper and lower parts in a direction perpendicular to the main vein, and the diameters of the main veins of the upper and lower parts of the leaves are measured using a vernier caliper (0.02 mm precision); wherein, at least three test points are selected along the main vein direction for each part of the tobacco leaves to measure the diameter, and the average value is taken as the main vein diameter of the part of the tobacco leaves. Branch vein diameter: three first-order branch veins are selected for each part of the cured tobacco leaves obtained in the examples and comparative examples, and the diameters of the branch veins are measured using a vernier caliper, and the average value is taken as the branch vein diameter of the tobacco leaves. The detection results are shown in Figure 2 and Table 1 below.

[0089] Table 1.

[0090]

[0091] As can be seen from Table 1, in the present application, by controlling the soil condition to be sandy loam soil, and limiting the pH value, organic matter content, available potassium content, available phosphorus content, and alkali-hydrolyzable nitrogen content in a specific range, the main vein diameter and branch vein diameter of the tobacco leaf can be reduced, and the difference in main vein diameter between the upper and lower parts of the tobacco leaf can be reduced, thereby obtaining a tobacco leaf with small and uniform vein diameter, which is suitable for use as a cigar wrapper.

[0092] Tobacco leaf component detection

[0093] The conventional chemical component contents of the cured and fermented tobacco leaves obtained from Comparative Example 1 (CK) and Examples 1-3 were detected: the conventional chemical components of the tobacco leaves were determined according to YC / T 159-2019 “Determination of Water-soluble Sugars in Tobacco and Tobacco Products”, YC / T 161-2002 “Determination of Total Nitrogen in Tobacco and Tobacco Products”, YC / T 468-2021 “Determination of Total Plant Alkaloids in Tobacco and Tobacco Products”, YC / T 162-2011 “Determination of Chlorine in Tobacco and Tobacco Products”, and YC / T 217-2007 “Determination of Potassium in Tobacco and Tobacco Products”, 6 biological replicates were performed, and each replicate was determined 3 times. The detection results are shown in Table 2.

[0094] Table 2.

[0095]

[0096] As can be seen from Table 2, under the soil condition, fertilization condition, topping condition, curing and fermentation condition of the present application, the shade treatment can improve the intrinsic chemical components of the tobacco leaf and improve the intrinsic quality of the cigar wrapper tobacco leaf.

[0097] The specific embodiments described herein merely illustrate the spirit of the present application. Those skilled in the art of the present application can make various modifications or supplements to the described specific embodiments or replace them with similar ways, without departing from the spirit of the present application or exceeding the scope defined by the appended claims.

Claims

1. A method of uniformly reducing the upper and lower leaf vein diameters of a cigar wrapper, characterized by: The method comprises the following steps: S1. Soil conditioning: adjusting the soil conditions to be: sandy loam, pH value of 5.5-7.5, organic matter content of 14-20 g / kg, available potassium content of 140-190 mg / kg, available phosphorus content of 30-40 mg / kg, and alkali-hydrolyzable nitrogen content of 90-110 mg / kg; S2. Sowing and transplanting: sowing in the soil and transplanting after ridging; Fertilization is performed per mu at the time of transplanting, and the fertilization ratio is: N:P2O5:K2O=1:(0.4-0.6):(2.2-2.7); 8-12 kg of potassium nitrate is top-dressed per mu after 25-30 days of transplanting; S3. Shading treatment: shading treatment is performed on the cigar during the growth period of the cigar; In step S3, the shading treatment is performed at a light transmittance of 75%-80% during the rosette stage and at a light transmittance of 90%-95% during the vigorous growth stage.

2. A method of uniformly reducing the diameter of the upper and lower veins of a cigar wrapper according to claim 1, characterized in that: In step S1, the soil conditions are adjusted to be: pH value of 5.6-6.9, organic matter content of 15.08-18.89 g / kg, available potassium content of 146.67-179.46 mg / kg, available phosphorus content of 31.08-36.82 mg / kg, and alkali-hydrolyzable nitrogen content of 96.7-106.8 mg / kg.

3. A method of uniformly reducing the diameter of the upper and lower veins of a cigar wrapper leaf according to claim 1, characterized in that: In step S1, 23-26 kg of quicklime is also applied per mu of soil.

4. A method of uniformly reducing the diameter of the upper and lower veins of a cigar wrapper leaf according to claim 1, characterized in that: In step S2, the row spacing is 105-115 cm and the plant spacing is 35-40 cm at the time of transplanting.

5. A method of uniformly reducing the diameter of upper and lower veins of a cigar wrapper according to claim 1, characterized in that: In step S2, the fertilization ratio is: N:P2O5:K2O=1:0.5:2.

5.

6. A method of uniformly reducing the diameter of upper and lower veins of a cigar wrapper leaf according to claim 1, wherein: The method further comprises the following steps: S4. Topping: when the cigar begins to bloom, the cigar is subjected to a topping treatment: 18-22 cm of leaves below the flower are retained, and the number of leaves remaining after topping is 16-20.

7. A method of uniformly reducing the diameter of upper and lower veins of a cigar wrapper according to claim 1, wherein: The method further comprises the following steps: S5. Conditioning: after the cigar leaves are picked, the cigar leaves are subjected to conditioning under the following conditions: 90-110 leaves per pole for the density of the bunched tobacco, 0.3-0.5 m for the pole spacing, and 0.8-1.0 m for the spacing between the two layers; The conditioning comprises the following steps in sequence: 4-5 days at a temperature of 24-26℃ and a relative humidity of 80%-85%; 5-8 days at a temperature of 25-28℃ and a relative humidity of 82%-87%; 5-8 days at a temperature of 28-30℃ and a relative humidity of 70%-75%; and 5-8 days at a temperature of 35-38℃ and a relative humidity of 40%-45%.

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