The live cultivation method of flue-cured tobacco can save labor in seedling raising, transplanting and top dressing; shorten the planting time; save peat and seedling trays; and eliminate the need for seedling greenhouses. It is a patent invented by the Guizhou Tobacco Science Research Institute and was disclosed by the State Intellectual Property Office on November 21, 2012. The operating points of this method are as follows:
The first step is to tidy up the tobacco field and open the sheds one and a half months in advance, apply base fertilizer along the center line of the ridge bottom, then make the ridges, and wait for rain to replenish the moisture in the ridges until the soil moisture reaches the desired level. adequate.
The second step is to drill a hole after the rain stops and apply plant ash mixed with an underground pest control agent into the hole.
The third step is to sow seeds in the holes, sow 1 seed in each hole, then spray transplanting elixir into the small holes until the plant ash and coated seeds absorb water and moisten, and cover with mulch.
The fourth step is to make holes in the film when the seeds germinate and grow to two leaves with one center. When the tobacco seedlings reach a height of 20cm, apply fertilizer again. Apply fertilizer to the hole at the root of the tobacco plant and fill it with soil. Fill the holes until the tobacco plant reaches a height of 50cm, then remove the film and cultivate the soil to prevent and control pests and diseases. Top and wipe the buds in time. Harvest and bake in time when mature. Our country began to study floating seedlings in the late 1990s. In the 20th century, floating seedling areas were gradually promoted and became the dominant seedling raising method. Floating seedlings have the advantages of high seedling efficiency, saving land for seedlings, reducing seedling labor, and reducing the occurrence of diseases, and are very popular among tobacco farmers. At present, various parts of our country are exploring different seedling raising methods, such as the moist seedling raising method. Floating seedlings mainly focus on reducing peat consumption and cost. Such as: semi-matrix seedling cultivation method and sand cultivation method. However, none of these can replace the mainstream floating seedling cultivation method in operation. It is expected that floating seedlings will remain the main method of raising flue-cured tobacco seedlings in my country for a long time to come.
Tobacco floating seedlings are a modern seedling technology that can be used for large-scale, professional, and commercial seedling production. It has many key technologies, complex processes, high management requirements, and key details are difficult to master. If the operation is not in place, , the floating seedlings bred have low quality, poor stress resistance, and the tobacco seedlings are diseased, which affects tobacco leaf production. To cultivate strong tobacco seedlings, four key points need to be grasped: first, strict disinfection throughout the entire process; second, scientific control of network, fertilizer, water and temperature; third, timely and appropriate leaf cutting and seedling hardening; fourth, strengthening prevention and control of pests and diseases.
After the tobacco seedlings emerge, as the temperature continues to rise, the tobacco seedlings grow faster, so strengthening management is particularly important. Therefore, we should focus on cultivating strong seedlings and strengthen the management of five aspects including fertilizer, water, and temperature.
First, strengthen water and fertilizer management. The principle of pool water management is "shallow first and then deep". After sowing, the temperature is low and the depth of the pool water should be controlled at about 5 cm. After the Great Cross period, as the temperature rises, the pool water should gradually deepen to 10 to 15 centimeters. The principle of fertilizer management is "less first and then more". The first application of fertilizer is when the first true leaf appears. Fertilizer is calculated in trays, 25 grams per tray. The nutrient liquid fertilizer must be dissolved first, then mixed and applied into the pool water in batches; the second fertilization is carried out when the third true leaf appears. The amount and method of fertilization are the same as the first time, and the depth of the pool water is 10 to 15 cm; The third fertilization is about 15 days after the second fertilization. At this time, the tobacco seedlings will generally show obvious fertilizer deficiency, and the appropriate amount of fertilizer is 20 grams. Fertilization should be flexibly controlled, and appropriate top dressing should be applied according to the leaf color.
The second is to strengthen temperature and humidity management. The suitable temperature for seed germination is 25°C to 28°C, and the suitable temperature for growth is 20°C to 25°C. It cannot be higher or lower than the lower limit temperature and upper limit temperature. Pay attention to the thermometer and carry out insulation and cooling management in a timely manner. Ventilation is generally carried out at noon when the temperature in the shed is higher than 28°C. In the afternoon, the shed should be closed for insulation; when the temperature drops suddenly, the shed film and sunshade net should be tightly covered, and covered with a covering. Keep warm. After the second leaf cutting, the small shed should open the shed film, gradually remove the sunshade net, and open the ventilation doors and windows of the large and middle sheds to allow the tobacco seedlings to gradually adapt to the external environment and achieve the purpose of seedling hardening. Due to abnormal weather changes, temperature and humidity management must be flexibly controlled.
The third is to strengthen the management of thinning, stabilizing seedlings and leaf pruning. When the tobacco seedlings reach the small cross stage, they need to be thinned. Thinning can improve ventilation and light transmission conditions and ensure the neatness of the tobacco seedlings. Before thinning, operators must prepare disinfection facilities and utensils, and promptly disinfect all objects that can come into contact with smoke seedlings.
When thinning out seedlings, first remove diseased and weak seedlings, and then fill the holes with excess healthy tobacco seedlings to ensure that there is one tobacco seedling in each hole; cut leaves at a timely manner to regulate the growth of the roots, stems and leaves of the tobacco seedlings. relationship. Disinfection measures before cutting leaves must be strict and disinfection must be in place. The first leaf cutting is carried out when the tobacco seedlings grow to 5 true leaves, and the tobacco seedlings that grow too fast are reduced by 1/2. The purpose is to "control the size and promote the smallness" and promote the neat and consistent growth of the tobacco seedlings. In the future, the leaves will be cut every 6 to 7 days, and the leaves will be cut 3 to 5 times to ensure the coordinated growth of the above-ground and underground parts of the tobacco seedlings. Root scraping Use bamboo chips to scrape away the root system that has grown out of the bottom hole to improve the toughness of the stem and promote root development. The leaves and root residues that are cut each time must be cleaned, and pesticides must be sprayed on the tobacco leaves in time before and after the leaves are cut, and disinfection must be carried out in a timely manner.
The fourth is to strengthen the management of forged seedlings. When the tobacco seedlings enter the seedling stage, the ventilation and light transmission conditions should be improved, the pool water should be filled, and the fertilizer should be cut off to temper the seedlings. Uncover the shed film on the small shed, and open the doors and windows of the large and middle sheds to make the seedlings in the seedling stage turn from true green to light green. The water in nursery ponds with dark green leaves should be replaced to ensure that the seedling growth rate is increased.
The fifth is to strengthen the prevention and control of pests and diseases. In the prevention and control of pests and diseases, we must adhere to the principle of "prevention first, comprehensive prevention and control", and focus on eliminating pathogens and controlling disease conditions. It is necessary to disinfect the nursery sites, nursery sheds, substrates, nursery trays and other links. Once the pathogenic centers are found, they must be promptly removed and control agents sprayed to prevent the spread. Diseases that are prone to occur in the seedling stage include: damping-off, damping-off, black shank, anthracnose, common mosaic, etc. Chlorothalonil, diclofenac, chlorothalonil, doxorubicin, doxorubicin, etc. can be used for prevention and control. Use the appropriate amount of medication according to the instructions. Pests that harm tobacco seedlings mainly include aphids, slugs, leafminers, etc. They can be controlled with trichlorfon, Wanling, pirimicarb, etc., and use appropriate amounts of pesticides according to the instructions. It is necessary to strictly control the concentration of phosphate fertilizer in the nutrient solution, strictly disinfect the seedling trays, substrates, and pool water, standardize tray loading operations, strengthen ventilation and light transmission, and reduce algae hazards. When algae appears, spray copper sulfate to kill algae. Strictly controlling the nutrient concentration of the nutrient solution can avoid salt damage. Smoke seedlings that have suffered salt damage should be sprayed with water or eliminated by changing the pool water.