2. Broccoli seedling raising and seedling management: it is cultivated in sunlight greenhouse in winter, and the outside temperature is low during seedling raising, so it is generally cultivated in sunlight greenhouse.
3. Preparation of nutrient soil: In order to ensure the robust growth of broccoli seedlings, it is best to use nutrient soil to raise seedlings. Nutrient soil consists of fertile field soil and decomposed fertilizer. Due to the different sources of fertilizers in different places, the preparation of nutrient soil is very different. There are two commonly used formulas for nutrient soil: one is 3 parts of fertile soil+4 parts of peat+3 parts of decomposed horse manure; The other is 6 parts of fertile soil+4 parts of decomposed manure. No matter which formula, the organic fertilizer used, such as horse manure, cow manure, pig manure, chicken manure, dried manure, etc. , completely decomposed before use.
4. Seeding amount of broccoli: The seeds of broccoli are very small. Before sowing, it is necessary to determine a reasonable sowing amount, ensure the number of seedlings used in the field, and ensure that the seedlings can have enough growth space on the seedbed. The formula of sowing amount is as follows: seed amount (g/mu) = [number of seedlings/mu× (1+safety factor )×1000-seed weight1000-germination rate.
5. Broccoli sowing method: Broccoli seeds are expensive and should be carefully sown. The common sowing method is broadcast sowing. Planting an acre of broccoli requires about 4 ~ 8 square meters of seedbeds. Sow in sunny and warm weather in the morning. Before sowing, water is poured into the seedbed. After water permeates, seeds are evenly spread into the seedbed, and then covered with 1 cm thick sieved fine soil or nutrient soil. When the supply of seeds is in short supply, we can also use the on-demand supply method. After water permeates, you can spread a layer of fine soil, draw a square of 10 cm on the seedbed, sow 1 ~ 2 seeds in the center of the square, and then cover it with soil with a thickness of 1 cm.
6. Seedbed management after broccoli sowing: After the seeds are sown, the sun bed should be covered with plastic film and covered with grass at night. Before the seedlings are unearthed, they are generally not ventilated. The temperature at seedling stage should be high, which should be kept at 20 ~ 25℃ during the day, 15 ~ 18℃ at night, and the ground temperature should not be lower than 15℃. At a suitable temperature, seedlings can emerge in 2 ~ 3 days. After emergence, the temperature should be reduced by about 2 ~ 3℃ to prevent the seedlings from growing in vain due to high temperature. At this time, the daytime temperature should be controlled at 20~22℃, and the nighttime temperature should be controlled at 14 ~ 16℃. After the cotyledons of broccoli seedlings are unfolded, they should be interplanted in time to keep the spacing between seedlings at about 65438±0cm. In order to prevent the ground temperature from decreasing, seedbeds are generally not watered.
7. Broccoli seedlings: When broccoli seedlings grow to 2 ~ 3 real leaves, they should be divided in time to prevent the seedlings from being crowded and growing in vain. Before dividing seedlings 1 day, water the edges of seedlings first to reduce root damage during seedling raising. Use the sun bed, small arch shed, etc. As a seedbed, there is no need to set up wind barriers. Like seedbeds, seedbeds should be filled with culture soil. In order to promote the delay of seedlings, seedlings should be divided in sunny morning. Seedlings are divided by sticking seedlings, that is, shallow ditches are opened in the seedbed with the row spacing of 10 cm, and water is poured. Before seepage, the seedlings should be planted in the ditch with the row spacing of 10 cm, and then covered with soil. The covering soil should not be too deep or too shallow, and it is appropriate to have the same depth as the original seedbed. After seedling separation, cover the sun bed with film and cover it with grass at night. After the seedlings are separated in the small arch shed, they are inserted into the arch frame and covered with film. You can cover it with grass to keep warm at night.
8. Seedling management of broccoli: In order to improve the seedbed temperature and promote seedling slow-down, there is generally no ventilation during seedling slow-down, so that the seedbed temperature reaches about 28℃ during the day. After 3 ~ 4 days, strengthen ventilation, and control the temperature at 15 ~ 20℃ during the day and above 10℃ at night and not lower than 8℃. 7 ~ 10 days before sowing, water the seedbed, cut into pieces and increase ventilation. Seedling temperature is controlled at 12 ~ 15℃ during the day and 8 ~ 10℃ at night. Broccoli seedlings are generally not topdressing, but can be sprayed on the leaves as appropriate. During the whole seedling raising period, try not to cover the seedlings with grass as much as possible during the day, so that the seedlings can see more sunlight and prevent them from yellowing and growing in vain. When the seedling stage is cloudy, it is also necessary to ensure that the seedbed has a certain time to see the light every day. When the seedlings grow to 5-7 true leaves, they can be planted.
9. Broccoli seedling standard: the plant has stout stems, short internodes, 5-7 true leaves, green, plump and waxy leaves, developed roots and no pests and diseases.