How to grow tobacco leaves Tobacco leaf cultivation techniques

High-quality tobacco cultivation techniques are as follows:

1. Environmental conditions for tobacco growth

1. Temperature: Tobacco is a warm-loving crop, and the above-ground part grows at 8 It can grow within the range of -38℃. The suitable temperature for growth and development is 25-28℃. Tobacco plants will die at minus 2-3℃. The underground part can grow between 7-43℃, but the most suitable temperature is 31℃. The optimal temperature for seed germination is 24-29℃, the minimum temperature is 7.5-10C, and the maximum temperature is 35C. When the temperature is lower than 7.5°C, the seed germination process stops; when the temperature is higher than 30°C, the germination process is slow; when the temperature exceeds 35°C, the germinated seeds will gradually lose their vitality. The tobacco transplanting period should generally be after the late frost and the temperature should not be lower than 10°C. The ideal daily average temperature during the leaf maturity period is about 24°C and lasts for 30 days to produce high-quality tobacco leaves.

2. Water: Generally, water is needed in the early stage of growth, most in the middle stage, and less in the later stage. It is advisable to keep the soil moisture at about 70% of the field water capacity during the seedbed stage. Stop water supply 10-15 days before transplanting to harden the seedlings. When transplanted to the seedling stage, the leaf transpiration is small, and the average daily water consumption is 3.5-6.4 mm. From the seedling stage to the clump stage, the average daily water consumption is 6.6-7.9 mm. It is advisable to keep the soil moisture at 60% of the field water capacity. If it is less than 40%, the growth will be stunted. If it is more than 80%, the root system will grow poorly, which is harmful to later growth. unfavorable. From the budding stage to the budding stage, the average daily water consumption is 7.1-8.5 mm, and it is advisable to keep the soil moisture at 80% of the field water capacity. If there is a lack of water during this period, the growth will be stunted. If there is a long-term drought, early flowering or early drying will occur. From budding to maturity, the average daily water consumption is 5.5-6.1 mm. It is advisable to keep the soil moisture at 60% of the field water capacity. The water should be slightly less during this period to improve the quality of tobacco leaves; if the soil moisture is too much, it will easily cause delays. Ripening and quality decline.

3. Sunshine: Tobacco always needs enough light, but most varieties do not have strict requirements on the length of sunshine. During the growth period, flue-cured tobacco requires sufficient but not very intense sunlight. The optimal lighting time is 8-10 hours a day. Especially in the mature period, sufficient sunlight is a necessary condition for producing high-quality tobacco leaves. Tantian, which is rich in short-wave light and warm, is conducive to improving the quality of tobacco leaves.

4. Soil: Although tobacco can grow on many types of soil, the soil requirements for growing high-quality tobacco are relatively strict. Red soil is the best, followed by red loess, sandy soil and mixed soil, while tidal soil (black soil) is the worst.

5. Weather phenomena: Strong winds and hail weather are more serious to tobacco leaves than to any other crops. They may cause serious losses whether in the seedbed or field stage. Therefore, tobacco cannot be grown in areas where strong winds and hail often occur during the tobacco growth period.

2. Tobacco cultivation and management

1. Seedling cultivation: Before the germination of tobacco seeds, they should be placed in the sun at 15-20℃ for 2-3 days to improve the quality of the seeds. Germination potential and germination rate. To cultivate strong seedlings, the first is to use a new technology of double-layer film paper tube seedlings. The diameter of the paper tube is not less than 4 cm and the height is 6-7 cm. 625 seedlings can be cultivated per square meter. A seedbed of 10 square meters can provide 4 acres. Used in tobacco field cultivation. The second is to prepare nutrient soil, using 60% field soil and 40% decomposed pig pen manure as the substrate. Each plot requires about 0.8-1 cubic meters of nutrient soil. After disinfection, 3-4 kg of compound fertilizer is added. Third, early sowing and transplanting at the right time can increase the yield by 20% and the quality by 25%. The Huanghuai tobacco area should be sown from around the beginning of spring to mid-February. The fourth is seedbed management. Since the temperature is low during sowing, it is susceptible to low temperature hazards. It must be timely controlled according to the temperature and humidity requirements for the growth of tobacco seedlings. Generally, two times of thinning are carried out, the first time is done after the "cross stage", the seedling spacing is 1.5-2 cm, the second thinning (defining) the seedlings is done when there are 4-5 true leaves, the seedling spacing is 6-8 cm.

2. Transplanting: Timely and early planting is a key part of producing high-quality tobacco. The best transplanting period in the Huanghuai tobacco area should be completed between Qingming Festival and Grain Rain. The planting density should be controlled at 1200-1300 plants per acre. Using plastic film to cover tobacco planting can not only increase temperature and moisturize, but also improve the drought and waterlogging resistance of tobacco plants and prevent tobacco leaves from blackening. If it rains before transplanting, you can cover it with film in time after the rain to preserve moisture and increase temperature.

If there is no rain, you should bring enough water when planting tobacco, and cover it tightly with the mulch film after planting. (If you plant tobacco before and after Qingming Festival, because the temperature is low, you can cover the cigarettes first and then expose the seedlings, and then open the mulch film when the temperature stabilizes. , take out the tobacco seedlings and seal and press film on the roots to prevent water loss).

3. Field management: The most prominent problem in flue-cured tobacco production is the contradiction between production and quality. Generally speaking, the higher the output, the worse the quality, but it does not mean that the lower the output, the better the quality. Therefore, management must work hard to stabilize output and ensure quality. ①Appropriate amount of fertilization: Mainly base fertilizer and adopt new balanced fertilization technology. The amount of pure nitrogen fertilizer applied per acre before transplanting is 6 kg for low fertilizer fields, 5 kg for medium fertilizer fields, and 3-4 kg for high fertilizer fields. The appropriate ratio of nitrogen, phosphorus and potassium fertilizer is 1:2:3. When fertilizer deficiency is found in the middle and later stages, top-dressing fertilizers should be applied by foliar spraying. ② Timely irrigation and drainage: In the critical period when tobacco needs water, when the tobacco field is in drought, spraying 1-2 times can increase yield by 8.1-43.1% and improve quality. If tobacco fields are flooded for 1-2 days, production will be reduced by 47.8-65%. Pay attention to ditch cleaning and drainage in low-lying tobacco fields or during rainy seasons. ③ Pay attention to cultivating and cultivating the soil: Timely cultivating during drought is of great significance for moisture conservation and water storage. Timely cultivating after rain can reduce soil moisture, increase soil permeability, increase ground temperature, and promote root growth. Cultivating can also eliminate weeds and reduce pests and diseases. Combined with cultivating and timely soil cultivation, it can promote the development of new roots, expand the ability to absorb water and fertilizer, facilitate drainage and prevent waterlogging, and enhance the ability to resist drought, wind and lodging. ④ Timely topping and debranching: Topping and debranching can not only increase the yield by 31-49%, but is also the main way to improve the quality of tobacco. Topping should generally be done in two steps based on the number of leaves left, to promote tidy tobacco plants, consistent growth and yellowing, and facilitate baking. Plants and branches should be cleaned promptly. ⑤ Strengthen the prevention and control of pests and diseases: focus on prevention and combine pesticide control with manual killing.

3. Harvesting

Mature harvesting is one of the important links in the production of high-quality tobacco. The characteristics of mature tobacco leaves are: the leaves change from green to yellow-green, the hairs on the leaves fall off, and the angle of the stems and leaves increases (approximately 90 degrees). The main veins of the lower leaves turn white, the branch veins of the middle leaves turn white, the main branch veins of the upper leaves turn white, and yellow spots appear on the leaf surface, it can be harvested and roasted.