Method for topping Yunyan 87

Abstract

The invention discloses a method for topping Yunyan 87. The method comprises the steps that tobacco plant transplanting is completed from April 25 to May 5, and classified jointing and topping are carried out according to different growth vigor (early blossoming, poor growth vigor, general growth vigor, good growth vigor and good growth vigor) of tobacco plants. The method specifically comprises the following steps: in early flowering and topping, a method of'topping without leaf removal 'is adopted, the pitch is lengthened by 5cm, 16 leaves are reserved, and the plant height is controlled to be 80-85cm after topping; the growth vigor is poor, 18 leaves, 20 leaves, 22 leaves and 24 leaves are reserved on common tobacco plants, good tobacco plants and good tobacco plants respectively, and the plant heights are controlled to be 90-95 cm, 100-105 cm, 110-115 cm and 120-125 cm. Tests prove that the method remarkably improves the tobacco leaf yield and economic benefits, the average output value per mu and the first-class tobacco proportion are greatly improved, and the method is superior to a traditional topping method. The method can effectively solve the problems of unreasonable group structure and low tobacco yield and quality in the low-latitude and high-altitude tobacco area.

Description

Technical Field

[0001] The invention relates to a method for topping Yunyan 87 tobacco, and belongs to the technical field of flue-cured tobacco planting. Background Art

[0002] In the process of flue-cured tobacco cultivation, a reasonable plant structure is of great significance for improving tobacco leaf yield and quality. As a core raw material for high-quality cigarettes, the optimization of Yunyan 87's cultivation and management technology plays a key role in improving the appearance quality and sensory quality of tobacco leaves. Shuicheng District belongs to Liupanshui City, located in the western part of Guizhou Province, at a high altitude, and belongs to the mid-subtropical monsoon climate zone. The climate in this area is characterized by large high and low temperature differences, uneven precipitation distribution, and a long frost-free period. However, due to the high terrain and significant vertical differences in climate, the tobacco leaf growth environment is complex and changeable.

[0003] In the current Yunyan 87 cultivation practice, the transplanting time is usually controlled between April 25 and May 5. Fertilization is divided into two categories according to soil fertility: medium fertility and above medium fertility, and base fertilizer and organic fertilizer are applied respectively. However, the existing topping methods mainly include topping at the heart, topping at the bud, topping at the beginning of the flower, and topping at the full flower. These methods can form a good growth appearance of tobacco plants in years with normal climate, but they often have certain limitations when facing the complex climatic conditions and soil environment in low-latitude and high-altitude tobacco areas.

[0004] Specifically, the Yunyan 87 tobacco fields in low-latitude and high-altitude tobacco-growing areas often face the problem of unreasonable group structure, which is manifested in excessive growth due to excessive nutrition of the tobacco plants, or poor leaf development due to malnutrition. This unreasonable group structure easily leads to the production of umbrella-shaped and cone-shaped tobacco plants, which in turn affects the thickness, chemical composition and sensory quality of the tobacco leaves, and reduces the overall quality and market competitiveness of the tobacco leaves. In addition, during the secondary growth process after topping, if the existing topping method is improperly managed for fertilization or affected by climatic factors, it is easy to cause further imbalance in the morphology of the tobacco plants, increasing the difficulty of cultivation management.

[0005] Therefore, it is urgent to develop a new method for topping Yunyan 87 suitable for low-latitude and high-altitude tobacco areas, which can effectively improve the individual and group structure of tobacco plants, promote the normal expansion of leaves, improve the appearance and internal quality of tobacco leaves, and increase yield and economic benefits. This has important practical significance and application value for solving the current bottleneck problem that restricts the sustainable development of low-latitude and high-altitude tobacco areas and promoting the steady development of the flue-cured tobacco industry. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for topping a cloud smoke 87 to overcome the shortcomings of the prior art.

[0007] The technical solution of the present invention is: a method for topping Yunyan 87, the method comprising:

[0008] Transplanting was completed between April 25 and May 5;

[0009] The tobacco plants were divided into five categories: early flowering, poor growth, average growth, good growth and good growth. The corresponding topping treatment was adopted according to different growth conditions. The specific methods are as follows:

[0010] 1) The method of early flowering topping is jointing topping. When the internode length is 5 cm and the number of leaves is 16, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 80-85 cm;

[0011] 2) The method of topping with poor growth is jointing topping. When the internode length is 5 cm and the number of leaves is 18, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 90-95 cm.

[0012] 3) Growth trend: Generally, the method of topping is jointing topping. When the internode length is 5 cm and the number of leaves is 20, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 100-105 cm.

[0013] 4) The method of topping for plants with good growth is jointing topping. When the internode length is 5 cm and the number of leaves is 22, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 110-115 cm.

[0014] 5) The method of topping for plants with good growth is jointing topping. When the internodes are extended to 5 cm and the number of leaves is 24, topping can be carried out. After topping, 3-5 cm of stems should be left on the top leaves. After topping, the plant height should be 120-125 cm.

[0015] Furthermore, the early-flowering topping adopts a method of topping the flowers but not the leaves.

[0016] Furthermore, the fertilization requirements of the method are:

[0017] Medium fertility tobacco field: apply 60 kg to 65 kg of base fertilizer per mu;

[0018] Medium to high fertility tobacco fields: apply 50 kg to 55 kg of base fertilizer per mu;

[0019] Organic fertilizer use: commercial organic fertilizer ≥ 70 kg / mu, or farmyard manure 300 kg to 500 kg / mu;

[0020] Potassium fertilizer: 10 kg to 15 kg per mu;

[0021] General calcium: 20 kg per mu;

[0022] Special topdressing: 18 kg per mu;

[0023] Seedling-raising fertilizer: Apply 2.5 kg per mu.

[0024] The beneficial effects of the present invention are: compared with the prior art,

[0025] 1) The Yunyan 87 topping method of the present invention implements classified jointing topping according to the different growth potentials of tobacco plants (early flowering, poor growth, general growth, good growth and good growth), scientifically adjusts the number of leaves and plant height, and combines reasonable fertilization management to effectively improve the plant type structure of tobacco plants, promote tobacco plants to form excellent cylindrical tobacco plants, and increase the number of effective leaves. This method significantly improves the appearance quality, chemical composition and sensory quality of tobacco leaves, ensuring that the tobacco leaves are bright in color, sufficient in oil, loose in tissue structure and good in elasticity. At the same time, the test results show that the yield and economic benefits of tobacco plants using this topping method are significantly higher than those of traditional topping methods, and the per mu output value and the proportion of superior tobacco are greatly improved, which fully reflects the significant improvement of its economic benefits. The method has strong adaptability and is particularly suitable for low-latitude and high-altitude tobacco areas with complex and changeable climates. It can effectively deal with the problem of plant type imbalance caused by overnutrition or malnutrition, reduce the difficulty of cultivation management, and promote the uniform development and high-quality production of tobacco leaves. Therefore, the jointing and topping method of the present invention not only solves the problems of unreasonable group structure and low tobacco yield and quality in the prior art, but also provides strong technical support for the sustainable development of the flue-cured tobacco industry, and has broad application prospects and promotion value;

[0026] 2) The present invention adopts the method of "beating flowers but not leaves" during early flowering topping, which significantly optimizes the growth management of Yunyan 87 tobacco plants. By only removing the flower buds and retaining the leaves, it not only effectively delays the tobacco plants from entering the reproductive growth stage too early, avoids the problems of insufficient leaf quantity and quality decline caused by early flowering, but also promotes the rational distribution of nutrients, ensuring that the leaves are fully expanded and develop normally. This method can prevent the formation of cone-shaped tobacco plants and cone-shaped tobacco plants, maintain the cylindrical structure of the tobacco plants, improve the uniformity and thickness of the leaves, thereby improving the appearance quality of the tobacco leaves and the coordination of the chemical composition. In addition, retaining more leaves helps to enhance the photosynthetic capacity of the tobacco plants, increase the total sugar content and nicotine level of the tobacco leaves, and further improve the sensory quality and economic value. In summary, the early flowering topping method of "beating flowers but not leaves" not only effectively improves the individual and group structure of the tobacco plants, improves the quality and yield of tobacco leaves, but also significantly increases the per-mu economic benefits, providing strong technical support for the sustainable development of Yunyan 87 in low-latitude and high-altitude tobacco areas, and has broad application prospects and promotion value;

[0027] 3) The fertilization requirement of the present invention is to scientifically and reasonably configure the amount of basal fertilizer and organic fertilizer for tobacco fields with different fertility, so as to ensure that the Yunyan 87 tobacco plants obtain sufficient and balanced nutrition supply under different soil conditions. For tobacco fields with medium fertility, 60 kg to 65 kg of basal fertilizer is applied per mu, while for tobacco fields with medium to high fertility, 50 kg to 55 kg of basal fertilizer is applied per mu, which avoids the problem of excess or insufficient nutrition and promotes the healthy growth of tobacco plants. The use of commercial organic fertilizer ≥ 70 kg / mu or farmyard manure 300 kg to 500 kg / mu can effectively improve the soil structure, enhance soil fertility and water and fertilizer retention capacity, and promote root development and soil microbial activity. Potassium fertilizer is applied at 10 kg to 15 kg per mu to improve the disease resistance and leaf quality of tobacco plants; general calcium is applied at 20 kg per mu, which helps to enhance the strength of leaf cell walls and improve the elasticity and durability of leaves. Special topdressing is applied at 18 kg per mu and seedling fertilizer is applied at 2.5 kg per mu to ensure the rapid recovery and continuous growth of tobacco plants after topping, and promote the full expansion and uniform development of leaves. The overall fertilization plan optimized the nutrient distribution of Yunyan 87, prevented the imbalance of plant shape and the decline of leaf quality caused by improper fertilization, and significantly improved the appearance quality, chemical composition and sensory quality of tobacco leaves, thereby increasing tobacco leaf yield and economic benefits. This scientific fertilization management method has strong adaptability and promotion value, and can effectively support the sustainable cultivation of Yunyan 87 in low-latitude and high-altitude tobacco areas, and promote the steady development of the flue-cured tobacco industry. DETAILED DESCRIPTION

[0028] Embodiment 1:

[0029] The current topping methods are topping at the heart, bud, initial flowering and full flowering stages, but these topping methods are not suitable for Yunyan 87 tobacco plants that have secondary growth after topping. For example, unreasonable fertilization and the influence of climatic factors may lead to conical tobacco plants and conical tobacco plants with enlarged or thin leaves after topping.

[0030] The first type: early flowering and topping: climate, 1. After transplanting in low-latitude and high-altitude tobacco areas, the lowest temperature in May is below 13℃ for more than 15 days. Early flowering in the flue-cured tobacco growing season, especially in the early stage, the temperature below 13℃ can promote the early development of tobacco plants, and it is easy to form early flowering, thereby reducing the yield and quality of tobacco leaves. 2. After transplanting, the temperature is high in May and June, the rainfall is small, the evaporation is increased, the soil moisture content is reduced, the tobacco plants are insufficiently supplied with water, the growth is inhibited, and the photosynthetic products supply the needs of growth and development. The tobacco plants are shorter than normal plants, and the leaves do not reach the number that the variety should have before entering reproductive growth, and early flowering occurs, thereby reducing the yield and quality of tobacco leaves. For early flowering formed in two climates: the method of topping without leafing and jointing topping is adopted. When the internode lengthens by 5cm and the number of leaves is left at 16, topping is performed. After topping, 3-5cm of stems are left on the top leaves, and the plant height after topping is 80-85cm.

[0031] The second method: topping of tobacco plants with poor growth: the method of jointing topping is to top the plants when the internodes are extended to 5cm and the number of leaves is left at 18. After topping, 3-5cm of stems are left on the top leaves. After topping, the plant height is 90-95cm.

[0032] The third type: Topping of tobacco plants with average growth: The method of topping by jointing is to top when the internodes are extended to 5cm and the number of leaves is left at 20, and then topping is carried out. After topping, 3-5cm of stems are left on the top leaves, and the plant height is 100-105cm after topping.

[0033] The fourth type: topping of tobacco plants with better growth: the method of jointing topping is to top the plants when the internodes are extended to 5cm and the number of leaves is 22. After topping, 3-5cm of stems are left on the top leaves. After topping, the plant height is 110-115cm.

[0034] Fifth type: Topping of tobacco plants with good growth: The method of topping by jointing is to top when the internodes are extended to 5cm and the number of leaves is left at 24, and then topping is carried out. After topping, 3-5cm of stem is left on the top leaves, and the plant height is 120-125cm after topping.

[0035] Transplanting requirements: In tobacco areas with higher altitudes, transplanting is completed from April 25 to May 5. The transplanting cycle within the same area is controlled within 5 days, and the transplanting cycle for each tobacco farmer is controlled within 3 days.

[0036] Fertilization requirements: For tobacco fields with medium fertility, 60kg to 65kg of basal fertilizer should be applied per mu; for tobacco fields with medium to high fertility, 50kg to 55kg of basal fertilizer should be applied per mu; commercial organic fertilizer should be ≥ 70kg per mu or farmyard manure should be 300kg to 500kg per mu. Potassium fertilizer should be 10kg to 15kg per mu, general calcium fertilizer should be 20kg, special topdressing fertilizer should be 18kg per mu, and seedling fertilizer should be 2.5kg per mu.

[0037] Test 1:

[0038] Early flowering topping, set up 1 control, 3 treatments, each treatment 1200 tobacco plants. The control removed the flower buds according to the conventional production operation and removed the leaves on the flower buds and topping; treatment 1 removed the flower buds and 2 leaves below the flower buds to remove the topping; treatment 2 removed the flower buds and 3 leaves below the flower buds to remove the topping; treatment 3 when the internode length is extended by 5cm, the number of leaves is left at 16, and then topping is carried out. After topping, 3-5cm of stems are left on the top leaves, and the plant height after topping is 80-85cm. The agronomic traits were measured one day before the start of baking, and the appearance quality and smoking quality of the baked tobacco leaves were measured by X2F, C3F, and B2F, the ratio of superior tobacco, and the average price per mu and average income.

[0039] Table 1 Agronomic characteristics of tobacco leaves in each treatment

[0040]

[0041] Treatment 3 was able to form a cylindrical plant with high-quality tobacco leaves, with 16 leaves remaining.

[0042] Treatment 3 significantly increased plant height (81.3 cm) and number of effective leaves (14 leaves), forming a cylindrical tobacco plant, which was superior to the cone-shaped plant of the control group and the umbrella-shaped plant of treatments 1 and 2.

[0043] The plant heights of the control group and treatments 1 and 2 were lower and the plant shapes were not ideal.

[0044] Table 2 Evaluation of the appearance quality of tobacco leaves treated

[0045]

[0046] The tobacco leaves of treatment 3 were orange in color, bright in luster, rich in oil, loose in texture, and good in elasticity, which was superior to those of the other treatment groups.

[0047] Table 3 Chemical components of tobacco leaves treated

[0048]

[0049] The total sugar, reducing sugar, total nitrogen, nicotine, potassium chloride and sugar / alkali ratio in the lower, middle and upper parts of treatment 3 were all within the standard range, while the control group and treatments 1 and 2 were low or high in some indicators.

[0050] Table 4 Sensory quality evaluation of tobacco leaves treated

[0051]

[0052] Treatment 3 had the highest total score (74.5 points) in terms of aroma quality, aroma quantity, and impurities, which was significantly better than the control group (67.5 points) and treatments 1 and 2.

[0053] Table 5 Economic characteristics of tobacco leaves in each treatment

[0054]

[0055] The yield (114.5 kg / mu), average price (31.90 yuan / kg) and output value (3652.55 yuan / mu) of treatment 3 were significantly higher than those of the control group and treatments 1 and 2.

[0056] Overall conclusion: Treatment 3 (jointing topping method) performed best in improving plant structure, tobacco leaf quality and economic benefits, and was significantly better than traditional topping methods and other treatments.

[0057] Test 2:

[0058] Tobacco plants with poor growth were toppled, with 1 control and 3 treatments, each with 1,200 plants. The control was operated according to routine production. When the flower buds were still wrapped in the top leaves like peas, the young leaves were carefully peeled off, and the flower buds were removed with tweezers or small bamboo sticks for topping; in treatment 1, the heart and the 2 leaves below the buds were removed for topping; in treatment 2, the heart and the 2 leaves below the buds were removed for topping, and the 3 leaves were removed for topping; in treatment 3, when the internode length was elongated by 5 cm and the number of leaves was left at 18, topping was performed again. After topping, 3-5 cm of stems were left on the top leaves, and the plant height was 90-95 cm after topping. The agronomic traits were measured one day before the start of baking. The appearance quality and smoking quality of the baked tobacco leaves were measured by X2F, C3F, and B2F, the ratio of superior tobacco, and the average price per mu and average income.

[0059] Table 6 Agronomic characteristics of tobacco leaves in each treatment

[0060]

[0061] Treatment 3 can form a cylindrical plant with high-quality tobacco leaves, with 18 leaves remaining. Treatment 3 significantly increased plant height (93.6 cm) and effective leaf number (16 leaves), forming a cylindrical tobacco plant, which is better than the umbrella-shaped plants of the control group and treatments 1 and 2.

[0062] Table 7 Evaluation of the appearance quality of tobacco leaves treated

[0063]

[0064]

[0065] The tobacco leaves of treatment 3 were orange in color, bright in luster, rich in oil, loose in texture, and good in elasticity, which was superior to those of the other treatment groups.

[0066] Table 8 Chemical components of tobacco leaves treated

[0067]

[0068] The total sugar, reducing sugar, total nitrogen, nicotine, potassium chloride and sugar / alkali ratio in the lower, middle and upper parts of treatment 3 were all within the standard range, while the control group and treatments 1 and 2 were low or high in some indicators.

[0069] Table 9 Sensory quality evaluation of tobacco leaves treated

[0070]

[0071] Treatment 3 had the highest total score (75.5 points) in terms of aroma quality, aroma quantity, and impurities, which was significantly better than the control group (68.5 points) and treatments 1 and 2.

[0072] Table 10 Economic characteristics of tobacco leaves in each treatment

[0073]

[0074]

[0075] The yield (116.4 kg / mu), average price (32.12 yuan / kg) and output value (3738.768 yuan / mu) of treatment 3 were significantly higher than those of the control group and treatments 1 and 2.

[0076] Overall conclusion: Treatment 3 (jointing topping method) performed best in improving plant shape, tobacco leaf quality and economic benefits, and was significantly better than traditional topping methods and other treatments.

[0077] Test 3:

[0078] Tobacco plants with normal growth were topped, with 1 control and 3 treatments, each with 1,200 tobacco plants. The control was operated according to conventional production. When the flower buds grew to 4-6 cm in length, the flower buds and young leaves were clearly separated. At this time, the flower buds, pedicels and 2-3 leaflets below were removed together; treatment 1 had begun to top the flower buds; treatment 2 had the flower buds and young leaves separated and topped; treatment 3 was topped when the internode length was 5 cm and the number of leaves was 20. After topping, 3-5 cm of stems were left on the top leaves, and the plant height was 100-105 cm after topping. The agronomic traits were measured the day before the start of the roasting. The appearance quality and smoking quality of the roasted tobacco leaves were measured using X2F, C3F, and B2F, the ratio of superior tobacco, and the average price per mu income.

[0079] Table 11 Agronomic characteristics of tobacco leaves in each treatment

[0080]

[0081] Treatment 3 can form a cylindrical plant with high-quality tobacco leaves, with 20 leaves remaining. Treatment 3 significantly increased plant height (104.9 cm) and effective leaf number (18 leaves), forming a cylindrical tobacco plant, which is better than the umbrella-shaped plants of the control group and treatments 1 and 2.

[0082] Table 12 Evaluation of the appearance quality of tobacco leaves treated

[0083]

[0084]

[0085] The tobacco leaves of treatment 3 were orange in color, bright in luster, rich in oil, loose in texture, and good in elasticity, which was superior to those of the other treatment groups.

[0086] Table 13 Chemical components of tobacco leaves treated

[0087]

[0088] The total sugar, reducing sugar, total nitrogen, nicotine, potassium chloride and sugar / alkali ratio in the lower, middle and upper parts of treatment 3 were all within the standard range, while the control group and treatments 1 and 2 were low or high in some indicators.

[0089] Table 14 Sensory quality evaluation of tobacco leaves treated

[0090]

[0091] Treatment 3 had the highest total score (78.5 points) in terms of aroma quality, aroma quantity, and impurities, which was significantly better than the control group (72.5 points) and treatments 1 and 2.

[0092] Table 15 Economic characteristics of tobacco leaves in each treatment

[0093]

[0094] The yield (126.2 kg / mu), average price (33.43 yuan / kg) and output value (5232.666 yuan / mu) of treatment 3 were significantly higher than those of the control group and treatments 1 and 2.

[0095] Test 4:

[0096] Tobacco plants with good growth were topped, with 1 control and 3 treatments, each with 1,200 tobacco plants. The control was operated according to conventional production. The top inflorescence extended out of the top leaf. When the first central flower on the main axis just opened, the entire inflorescence and the 2 leaflets below it were removed and topped; Treatment 1 was topped when the first central flower opened, and the entire inflorescence and the 3 leaflets below it were removed and topped; Treatment 2 was topped when the first central flower opened, and the entire inflorescence and the 4 leaflets below it were removed and topped; Treatment 3 was when the internode lengthened by 5 cm, the number of leaves left was 22, and the plant height after topping was 110-115 cm. The agronomic traits were measured the day before the start of the roasting. The appearance quality and smoking quality of the roasted tobacco leaves were measured by X2F, C3F, and B2F, the ratio of superior tobacco, and the average price per mu and average income.

[0097] Table 16 Agronomic characteristics of tobacco leaves in each treatment

[0098]

[0099] Treatment 3 can form a cylindrical plant with high-quality tobacco leaves, with 22 leaves remaining. Treatment 3 significantly increased plant height (114.2 cm) and effective leaf number (20 leaves), forming a cylindrical tobacco plant, which is better than the umbrella-shaped plants of the control group and treatments 1 and 2.

[0100] Table 17 Evaluation of the appearance quality of tobacco leaves treated

[0101]

[0102]

[0103] The tobacco leaves of treatment 3 were orange in color, bright in luster, rich in oil, loose in texture, and good in elasticity, which was superior to those of the other treatment groups.

[0104] Table 18 Chemical components of tobacco leaves treated

[0105]

[0106] The total sugar, reducing sugar, total nitrogen, nicotine, potassium chloride and sugar / alkali ratio in the lower, middle and upper parts of treatment 3 were all within the standard range, while the control group and treatments 1 and 2 were low or high in some indicators.

[0107] Table 19 Sensory quality evaluation of tobacco leaves treated

[0108]

[0109] Treatment 3 had the highest total score (84 points) in terms of aroma quality, aroma quantity, and impurities, which was significantly better than the control group (74 points) and treatments 1 and 2.

[0110] Table 20 Economic characteristics of tobacco leaves in each treatment

[0111]

[0112] The yield (143.4 kg / mu), average price (34.78 yuan / kg) and output value (5232.666 yuan / mu) of treatment 3 were significantly higher than those of the control group and treatments 1 and 2.

[0113] Test 5:

[0114] Tobacco plants with good growth were topped, with 1 control and 3 treatments, each with 1200 tobacco plants. The control was operated according to conventional production. When a large number of flowers had bloomed or were in full bloom, the entire inflorescence and the 2 leaflets below were removed and topped; when a large number of flowers had bloomed or were in full bloom, the entire inflorescence and the 3 leaflets below were removed and topped; when a large number of flowers had bloomed or were in full bloom, the entire inflorescence and the 4 leaflets below were removed and topped; when the internode length was 5cm and the number of leaves was 24, the topping was performed again in treatment 3. The plant height after topping was 120-125cm. The agronomic traits were measured one day before the start of the roasting. The appearance quality and smoking quality of the roasted tobacco leaves were measured by X2F, C3F, and B2F, and the ratio of superior tobacco, average price and average yield per mu were measured.

[0115] Table 21 Agronomic characteristics of tobacco leaves in each treatment

[0116]

[0117] Treatment 3 can form a cylindrical plant with high-quality tobacco leaves, with 24 leaves remaining. Treatment 3 significantly increased plant height (125.0 cm) and effective leaf number (22 leaves), forming a cylindrical tobacco plant, which is better than the umbrella-shaped plants of the control group and treatments 1 and 2.

[0118] Table 22 Evaluation of the appearance quality of tobacco leaves treated

[0119]

[0120] The tobacco leaves of treatment 3 were orange in color, bright in luster, rich in oil, loose in texture, and good in elasticity, which were significantly better than those of the control group and treatments 1 and 2.

[0121] Table 23 Chemical composition of tobacco leaves treated

[0122]

[0123] The total sugar, reducing sugar, total nitrogen, nicotine, potassium chloride and sugar / alkali ratio in the lower, middle and upper parts of treatment 3 were all within the standard range, while the control group and treatments 1 and 2 were low or high in some indicators.

[0124] Table 24 Sensory quality evaluation of tobacco leaves treated

[0125]

[0126] Treatment 3 had the highest total score (84 points) in terms of aroma quality (9 points), aroma quantity (9 points), impurities (9 points), concentration (9 points), strength (8 points), irritation (10 points), aftertaste (9.5 points), burnability (9 points), and gray (8.5 points), which was significantly better than the control group (74 points) and treatments 1 and 2.

[0127] Table 5 Economic characteristics of tobacco leaves in each treatment

[0128]

[0129] The yield (147.3 kg / mu), average price (34.78 yuan / kg) and output value (5123.09 yuan / mu) of treatment 3 were significantly higher than those of the control group and treatments 1 and 2, reflecting a significant improvement in economic benefits.

[0130] Comprehensive analysis and overall conclusion:

[0131] Through detailed analysis of five groups of experiments (experiments 1 to 5), the following comprehensive conclusions can be drawn:

[0132] The jointing topping method (treatment 3) can effectively improve the plant structure under all types of tobacco plant growth conditions, form cylindrical tobacco plants, and increase the number of effective leaves.

[0133] Treatment 3 was significantly superior to the traditional topping method (control group) and other treatments (treatment 1 and treatment 2) in terms of tobacco leaf appearance quality, chemical composition and sensory quality, thereby improving the overall quality of tobacco leaves.

[0134] In terms of economic traits, treatment 3 consistently achieved higher yields, better market prices, and higher per-acre returns, showing significant economic benefits and bringing greater economic benefits to tobacco farmers.

[0135] The jointing and topping method has strong adaptability and promotion value, and is especially suitable for low-latitude and high-altitude tobacco-growing areas. It can effectively cope with complex and changeable climate and soil conditions, improve tobacco leaf yield and quality, increase farmers' income, and promote the sustainable development of the flue-cured tobacco industry.

[0136] The jointing and topping method of the present invention optimizes the growth structure of tobacco plants through scientific classification and precise operation, improves the appearance quality and intrinsic quality of tobacco leaves, overcomes the limitations of traditional topping methods in low-latitude and high-altitude tobacco areas, and has broad application prospects and promotion value.

[0137] In order to verify the effect of leaving 3-5 cm of stems on the top leaves after topping, the applicant used the topping method, the traditional topping method (control group) and other treatments (treatment 1, treatment 2, treatment 3, treatment 4, treatment 5), and tested the necrosis rate (%) of the last 1-2 leaves and the incidence rate (%) of empty stem disease of the topping samples. The results are as follows:

[0138]

[0139] The results showed that the necrosis rate (%) of the last 1-2 leaves and the incidence rate of empty stem disease (%) of topping with this method were lower than those of other methods, and the comprehensive incidence rate was also lower than that of other methods.

[0140] Final conclusion:

[0141] The jointing topping method proposed in the present invention significantly improves the plant structure of Yunyan 87 tobacco plants by scientifically adjusting the timing of topping and the number of leaves left, combined with reasonable fertilization management, and improves the appearance quality, chemical composition and sensory quality of tobacco leaves, and greatly increases the yield and economic benefits. This method effectively solves the problems of unreasonable population structure and low tobacco yield and quality in low-latitude and high-altitude tobacco areas in the prior art, provides strong support for the sustainable development of the flue-cured tobacco industry, and has important practical significance and application value. In addition, through topping by this method, the necrosis rate (%) of the last 1-2 leaves and the incidence rate (%) of empty stem disease are lower than those of other methods, and the comprehensive incidence rate is also lower than that of other methods.

[0142] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for topping Yunyan 87, characterized in that: The method is: Transplanting was completed between April 25 and May 5; The tobacco plants were divided into five categories: early flowering, poor growth, average growth, good growth and good growth. The corresponding topping treatment was adopted according to different growth conditions. The specific methods are as follows: 1) The method of early flowering topping is jointing topping. When the internode length is 5 cm and the number of leaves is 16, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 80-85 cm; 2) The method of topping with poor growth is jointing topping. When the internode length is 5 cm and the number of leaves is 18, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 90-95 cm. 3) Growth trend: Generally, the method of topping is jointing topping. When the internode length is 5 cm and the number of leaves is 20, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 100-105 cm. 4) The method of topping for plants with good growth is jointing topping. When the internode length is 5 cm and the number of leaves is 22, topping is performed. After topping, 3-5 cm of stems are left on the top leaves. After topping, the plant height is 110-115 cm. 5) The method of topping for plants with good growth is jointing topping. When the internodes are extended to 6 cm and the number of leaves is 24, topping can be carried out. After topping, 3-5 cm of stems should be left on the top leaves. After topping, the plant height should be 120-125 cm.

2. The method for topping Yunyan 87 according to claim 1, characterized in that: The method of topping the early flowers is to remove the flowers but not the leaves.

3. The method for topping Yunyan 87 according to claim 1, characterized in that: The fertilization requirements of the method are: Medium fertility tobacco field: apply 60 kg to 65 kg of base fertilizer per mu; Medium to high fertility tobacco fields: apply 50 kg to 55 kg of base fertilizer per mu; Organic fertilizer use: commercial organic fertilizer ≥ 70 kg / mu, or farmyard manure 300 kg to 500 kg / mu; Potassium fertilizer: 10 kg to 15 kg per mu; General calcium: 20 kg per mu; Special topdressing: 18 kg per mu; Seedling-raising fertilizer: Apply 2.5 kg per mu.

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