When will the sweet potato seedlings be planted?
Sweet potatoes should be nursed back to health two months before transplanting, that is, spring potatoes should be nursed back to health in late June, autumn potatoes should be nursed back to health in late June and winter potatoes should be nursed back to health in early August. One-time seedling raising or staged propagation can be adopted.
Planting season and time of corresponding sweet potato seedlings:
Spring sweet potato: from late March to early April.
Autumn sweet potato: around the middle and late August.
Winter sweet potato:1mid-October.
Mid-April is the suitable period for seedling transplanting. At this time, the temperature rises in early spring and is basically stable all year round. The suitable time for sowing and seedling raising is when the ground temperature 10 cm reaches 15℃ or above after the end of late frost, and the seeds can be sown, and plowed in the sun in early winter or early last year, and ridged and ploughed again when sowing. The side strip is 50 cm wide. In early and middle April, according to the seedling emergence speed of seedbed, the seedlings were sown in different stubbles, and the number of potato seedlings buried in the soil and the number of potato nodes were increased by straight-line flat planting. Insert 3500-4000 plants per mu with a spacing of about 33cm.
How to plant sweet potato seedlings
Cultivation techniques of sweet potato seedlings
1. Site construction: The sweet potato nursery site should be built in sunny and well-ventilated sandy loam, depending on the demand. The peripheral wall can be made of bricks or mounds, about 60 cm high and 20 cm wide. In order to ensure uniform heating in all corners of the site, pipes should be laid in place and extend in all directions. If the cost is too high, the tunnel can be dug underground, criss-crossing, north-south access, and the entrance should be connected with the fire source.
2. Placement of potato pieces: After laying a layer of straw on the pipeline or passage, sprinkle fine soil to place potato pieces. Potato pieces must be fresh, shiny, spotless, medium-sized and slender. The potato pieces should be evenly placed in the field, with the vertical and horizontal spacing of about 2 ~ 3 cm, and then a thin layer of soil (with appropriate amount of chemical fertilizer) should be sprinkled and soaked in water, and the wall should be covered with plastic tarpaulin.
Cultivation and management of sweet potato seedlings
1, dimming: sweet potato likes light. Under the condition of sufficient light, the leaves are thicker in color, longer in age, stout in stems and vines, developed in stem conduction tissues and higher in yield. However, the requirements of sweet potato seedlings for sunshine are not too high, because the wall is always covered with plastic tarpaulins, and it will only be uncovered when the temperature is already high in the later period.
2. Humidity control: Sweet potato is a drought-tolerant crop, but too much and too little water is not conducive to increasing production. The growth of sweet potato seedlings needs to control water. With too little water, sweet potatoes will be cooked due to high temperature. If the humidity is too high, ventilate and bask in the sun. In short, we should always observe the dry humidity of the soil and strictly control it at around 50%.
3. Temperature control: The optimum temperature for the growth of sweet potato seedlings is 20 ~ 25 degrees. If it is lower than 20 degrees, it is necessary to increase the intensity of burning firewood and cover it with plastic tarpaulins. If the temperature is higher than 25 degrees, to reduce firewood, you can also lift the plastic tarpaulin and strengthen ventilation and cooling. Generally speaking, the ignition starts at the beginning of February, and it burns for about an hour every morning and evening, and the ceasefire can be stopped in 15 ~ 20 days, and the temperature has little effect.
4. Broken soil is helpful for growth: sweet potato seedlings begin to drill out of the soil layer after about 15 days under the good control of sunshine, temperature and humidity. Because the potato pieces are dense, it seems that the whole site is convex. At this time, wooden boards should be put on the fence, and people should stand on it, carefully lift the clods, crush them by hand and spread them out, which can reduce the pressure of potato seedlings, maintain soil moisture and help them grow.
5. Temperature difference control: sweet potato seedlings grow fastest at night, but due to the large temperature difference between day and night, plastic tarpaulins should be covered tightly at night, and a straw mat can be laid to prevent the temperature from falling too fast, which is not conducive to the growth of potato seedlings.
6. Timely picking: After the sweet potato seedlings become seedlings, put the board on the fence. When picking, people should stand up and pick carefully. If the yellowing of potato seedlings will affect the sales of potato seedlings, you can spray pesticide "one spray green" to make them green, and the price will not be affected.