How to Grow Flue-Cured Tobacco? A Detailed Guide to Flue-Cured Tobacco Cultivation Techniques

Flue-cured tobacco is the tobacco type with the largest cultivated area in our country and in the world; it is the main raw material for the cigarette industry, and is also used as pipe tobacco and as a raw material for the tobacco industry. So what are the flue-cured tobacco cultivation techniques?

1. Direct Seeding Cultivation

The direct seeding cultivation method for flue-cured tobacco can save labor in seedling raising, transplanting and topdressing; shorten the planting time; save peat and seedling trays; and eliminate the need for seedling greenhouses. It is a patent invented by the Guizhou Provincial Tobacco Science Research Institute, and was published by the State Intellectual Property Office on November 21, 2012. The key operating points of this method are as follows:

Step one: a month and a half in advance, prepare the tobacco field and open the beds, apply base fertilizer along the center line of the ridge bottom, then form the ridges, and wait for rainwater to replenish the ridge body moisture until the soil moisture is sufficient.

Step two: after the rain stops, punch holes, and apply wood ash mixed with a pesticide against underground pests into the holes.

Step three: sow seeds in the holes, 1 seed per hole, then spray a transplanting agent into the small holes until the wood ash and coated seeds absorb water and become moist, and cover with plastic film.

Step four: after the seeds germinate and emerge and grow to the two-leaf-one-heart stage, break holes in the film; when the tobacco seedlings reach 20 cm in height, apply fertilizer again, applying the fertilizer into the holes at the roots of the tobacco plants, filling the holes with soil; after the tobacco plants grow to 50 cm in height, remove the film and earth up, control pests and diseases, top and remove buds in time, and harvest and cure in time after maturity.

2. Floating Seedling Raising

Tobacco floating seedling raising is a modern seedling production technique that can be carried out on a large scale, professionally and commercially. It involves many key techniques, complex procedures, high management requirements and difficult-to-master key details. If operations are not done properly, the floating seedlings produced are of low quality, have poor stress resistance, and carry diseases, affecting tobacco leaf production.

1. Strengthen water and fertilizer management. For pool water management, the principle is “shallow first, then deep.” After sowing, when the temperature is relatively low, the pool water depth should be controlled at about 5 cm. After the large cross stage, as the temperature rises, the pool water should gradually be deepened to 10-15 cm. For fertilizer management, the principle is “less first, then more.” The first fertilization is when the first true leaf appears, applying fertilizer per tray, 25 grams per tray. The nutrient solution fertilizer must first be dissolved, then mixed evenly and applied into the pool water in portions; the second fertilization is carried out when the third true leaf appears, and both the amount and method of fertilization are the same as the first time, with a pool water depth of 10-15 cm; the third fertilization is about 15 days after the second fertilization, at which time the tobacco seedlings generally show obvious signs of nutrient deficiency, and the fertilizer amount should preferably be 20 grams. Fertilization should be handled flexibly, with appropriate topdressing according to leaf color depth.

2. Strengthen temperature and humidity management. The suitable temperature for seed germination is 25°C-28°C, and the suitable temperature for growth is 20°C-25°C. Do not exceed or fall below the lower and upper temperature limits. Pay attention to observing the thermometer, and carry out heat preservation and cooling management in time. Ventilation is generally carried out at noon when the temperature inside the greenhouse is higher than 28°C, and in the afternoon the greenhouse should be closed to preserve heat; when the temperature drops suddenly, the greenhouse film and shade net should be tightly covered, and additional coverings should be added for heat preservation. After the second leaf clipping, the film of small greenhouses should be opened, the shade net gradually removed, and the ventilation doors and windows of large and medium greenhouses opened, so that the tobacco seedlings gradually adapt to the external environment and achieve the purpose of hardening. Because weather changes abnormally, temperature and humidity management should be controlled flexibly.

3. Strengthen thinning, final singling and leaf clipping management. When the tobacco seedlings grow to the small cross stage, thinning should be carried out. Thinning can improve ventilation and light conditions and ensure the uniformity of the tobacco seedlings. Before thinning, operators should prepare disinfection facilities and tools, and timely disinfect all objects that may contact the tobacco seedlings. When thinning, first remove diseased and weak seedlings, then fill the empty holes with surplus healthy tobacco seedlings, ensuring that each hole has 1 tobacco seedling; leaf clipping should be carried out at the right time to regulate the relationship between root growth and stem and leaf growth. Disinfection measures before leaf clipping must be strictly controlled and disinfection must be thorough. The first leaf clipping is carried out when the tobacco seedlings grow to 5 true leaves, cutting away 1/2 of the tobacco seedlings that grow too fast, with the purpose of “controlling the large and promoting the small,” promoting uniform and consistent growth of the tobacco seedlings. After that, clip leaves once every 6-7 days, clipping 3-5 times, to ensure coordinated growth of the aboveground and underground parts of the tobacco seedlings. For root scraping, use a bamboo strip to scrape away the roots growing out of the bottom holes, improving stem toughness and promoting root development. The leaves and root residues cut off each time should be cleaned up completely; pesticides should be sprayed promptly before and after leaf clipping, and disinfection treatment should be carried out in time.

4. Strengthen seedling hardening management. After the tobacco seedlings enter the mature seedling stage, ventilation and light conditions should be improved, the pool water filled up, and fertilizer cut off to harden the seedlings. Open the film on small greenhouses, and open the doors and windows of large and medium greenhouses, so that the seedling color at the mature seedling stage becomes normal green to light green. Seedling pools with dark green leaf color should have the pool water replaced to help increase the rate of strong seedlings.

5. Strengthen pest and disease control management. Pest and disease control should adhere to the principle of “prevention first, integrated control,” with control carried out mainly by eliminating pathogens and controlling disease-inducing conditions. Disinfection work must be done well in links such as the seedling raising site, seedling greenhouse, substrate and seedling trays. Once pathogen centers are found, they should be removed in time, and control agents should be sprayed at the same time to prevent spread.

3. Pest and Disease Control

In order to ensure normal growth and maturity of the tobacco plants, the preparation and disinfection of the cultivation soil should be done well in advance before the experiment begins, and attention should be paid to pest and disease control throughout the entire growth period, trying to nip pests and diseases in the bud. Before transplanting the tobacco seedlings, spray the tobacco seedlings with disinfectant drugs such as “Bingdu Kuaike,” and spray the cultivation soil holes with “Dikerson,” to prevent later disease onset; after transplanting, the seedlings should immediately be irrigated with a “Dihu Tucanqing” solution to prevent cutworms from biting off the seedling root systems.

Flue-cured tobacco cultivation saves time and labor, and economic returns are recovered relatively quickly, making it suitable for development and cultivation in many rural areas.