To cultivate sweet potato seedlings, high-quality, high-yield, disease-resistant sweet potato varieties should be selected, such as Beijing 553 and Jingshu 18, which mainly sell fresh potatoes, and Xushu 18 and Sweet Potato 98, which are mainly processed starch.
First, the construction seedbed will be built 30 to 40 days before planting, north-south direction, the middle of the bed is 0.5 meters deep, the north is 0.57 meters deep, and the south is 0.67 meters deep. In the bed, two ventilation grooves with a width and a depth of 0.15 meters are dug around the bed wall. The north side is 0.35 meters away from the wall, and the south side is 0.17 meters away from the wall. There is a vent and a ventilation groove in the middle of the bed between the east and the west. In the same way, the two outlets are high and low, which is convenient for air circulation. After digging the bed, the wall is built around the bed. It is 0.45 meters high in the north and 0.06 meters high in the south. The east and west sides are erected on both sides.
Second, brewing hot matter preparation with fresh horse manure, chopped corn stover mixed 1:2, then mix with urine, spread on the bottom of the bed, then cover the plastic film, cover the grass to heat up, when the temperature of the brewing When it is raised to 35 ° C, the hot material is stepped on and the thickness is 0.1 m. The surface is covered with 0.08 to 0.1 m bed soil, and 0.03 m sand is added.
Third, the seed potato treatment should be selected to have the characteristics of the original variety, the potato shape is correct, the potato block size is moderate, smooth and bright, and the seed potato is not cold, frozen, wounded or diseased.
Drug treatment: The method is to soak for 70 minutes with 70% pure methyl thiophanate for 800 minutes.
Fourth, the potato is placed on the bed and the head of the potato is facing up, and the potato head is pressed 1/3 of the potato tail. After seeding, the bed soil is grounded with warm water of about 40 °C (about 10 kg per square meter), and the surface is covered with a layer of sand about 0.03 m.
Five, seedbed management
1. Warming and heat preservation. The seedling temperature should be maintained at 34 °C ~ 37 °C within 3 days after bedtime, and kept at 32 °C for 4-7 days. The bed temperature before emergence should be maintained at 30 °C ~ 32 °C; after emergence, the seedling growth gradually decreased to 25 °C. about. One to two days after picking, it is necessary to increase the temperature and keep warm.
2. Adjust the moisture. The bed soil moisture is maintained at 70% to 80% of the maximum water holding capacity of the soil.
3. Refining seedlings. After the potato seedlings are out, choose sunny day to gradually ventilate and cool down. After the seedling height is 0.1 m, it can be ventilated day and night. Before the picking, the low temperature refining will be carried out, and the bed temperature will drop to 20 °C ~ 22 °C.
4. Topdressing. After each picking, the quick-acting nitrogen fertilizer was used as the top dressing, and 0.05 kg of ammonium sulfate per square meter and 0.05 kg of potassium dihydrogen phosphate.
Sixth, the seedlings are harvested in time. Sweet potato seedling standard: seedling age 30 to 35 days, the seedling leaves are bright green, the leaves are large and thick, the top three leaves are flush, the stem section is thick, and the root primordia is many (diameter 0.5 cm, internode 3 to 4 cm), stem is not easy Breaking, when the stem is broken, the white pulp is thick and thick, and the whole plant has no disease spots. The height is 20-25 cm, the minimum is 8-9 knots, and the fresh weight of 100 plants is 0.5 kg or more.
At present, in order to better control the disease of sweet potato, the technology of high-cutting of sweet potato is strongly advocated, that is, the seedling is cut from the base of the seedling by 3 to 5 cm, and the base of the potato seedling can be cut off after the seedling is raised. 5 cm can be. The premise is that high-cut seedlings should be properly smelted for more than 3 days, basically not affecting the survival rate (Azure).
Led Ceiling Fan,Fanimation Ceiling Fans,Bedroom Ceiling Fans,Windmill Fan
JIANGMEN ESCLIGHTING TECHNOLOGY LIMITED , https://www.esclightingfan.com