Pingnan Junong Mountain Farming Specialized Farmers Cooperative
Seed reproduction and production mostly adopt the method of sowing and raising seedlings and then transplanting and planting. The southern provinces of China usually use flat borders for sowing seedlings, while in the north, hotbeds are used to raise seedlings. The sowing period on the south bank of the Yangtze River is between 10 and 11 months. The seedlings will live through the winter in the nursery border, and they can be transplanted to the field for cultivation in mid-to-late March of the following year. In the north, greenhouses or hotbeds are generally used for sowing and raising seedlings in 24 months. In order to spread the seeds evenly, the seeds can be mixed with fine sand and rubbed before sowing, and then soaked in warm water for 10-12 hours, and then dress the seeds with a small amount of vegetation. After sowing, use a wooden board to lightly press the seeds to make contact with the soil, and then use a sprayer to spray water on the bed surface once to keep the bed moist and increase the rate of emergence. The temperature and humidity are suitable, and it can germinate and unearth 7-10 days after sowing. Sown amount: 500 grams per 100 square meters of seedbed, the actual number of strong seedlings cultivated is 200,000-250,000, which is enough to plant 12-15 acres of land. Generally, 8000-9000 seedlings are planted per acre, and the dense planting can reach 10000-12000.
Cutting propagation can be cut from late March to late August, and the survival rate of cutting cuttings before budding is higher. When cutting cuttings, select robust branches and lateral stems that meet the requirements, cut off a 15-20 cm long section, and insert 1/3-l/2 of the cuttings into the bed soil, with a row spacing of 2 cm × 5 cm. Water in time after insertion, cover the top with straw curtain or plastic film, keep it warm at night, avoid direct sunlight at noon, properly ventilate and transmit light when new shoots grow, gradually strengthen the adaptability of the seedlings to the outside world, and form a developed root system, stems and leaves Strong, normal-colored seedlings.
In addition, although the layering can also be used for reproduction, it is limited to the use of keeping good individual plants in the selection work, and is not suitable for large-scale cultivation and production.
For spring planting, about 10-20 square meters of seedlings are needed for each acre of stevia planted. Scrub the crown hair before planting and soak in clean water overnight. When sowing seeds, fill the seedbed with sufficient water first, and after the water seeps in, sprinkle the seeds evenly on the seedbed, and then cover the seeds with fine sand or fine soil, with the seeds half exposed and half buried. Finally, use bamboo sticks to make an arch, and cover the seedbed with mulch. Generally, the seedlings can emerge within 5-6 days, and the seedlings should be refined after emergence. When the seedlings grow to 5-6 pairs of true leaves, they can be transplanted when the temperature is above 15°C. Generally, the row spacing is 30-40 cm; the plant spacing is 15-20 cm. Water enough root water when transplanting.