Seedling management of broccoli

First, the management of emergence stage:

The main results are as follows: 1. From sowing to germ unearthing stage: mainly to provide sufficient water and suitable temperature conditions. Those sown in autumn need to build an Arbor to cool down and raise seedlings. After sowing, pour enough water and cover with straw or sunshade net to moisturize. Sowing in autumn due to high temperature, water should be sprayed once in the morning and evening every day to keep the soil moist. Generally, buds can sprout one after another 3 days after sowing, and when 30% of the seed germ is exposed to the soil, the cover is removed.

2. From the appearance of cotyledons to the heart-exposed stage of the first true leaf: the moisture content should be properly controlled and the temperature should be lowered to prevent the formation of tall seedlings.

3. True leaves are exposed to the stage of seedling division: if the sowing is too dense, time seedlings should be pulled out, and the weak seedlings that are overcrowded or poorly growing should be pulled out, and the light, ventilation and cooling should be strengthened appropriately to prevent the occurrence of excessive growth and sudden collapse of seedlings.

(2) Seedling (false planting):

Generally, about 15 days after sowing, the seedlings are divided (pseudo-planting) when the seedlings grow to 2 Mel 3 true leaves. One day before seedling division, the seedling bed should be watered thoroughly in order to reduce the root injury during seedling emergence. After raising the seedlings, transplant the seedlings to the sub-seedling bed according to 6ml / 8cm square. Before transplanting, first pierce a small hole with a finger or a round stick in the middle of each earthwork of the seedling bed, and then plant it when it is wet and dry. The planting should be shallow and the eyes should be sealed with fine dry soil around the seedlings. If there are conditions, it is best to move directly into the nutrition cup or seedling tray and plant 1 seedling in each cup. Planting should be carried out in the evening, while moving seedlings, while watering, while shading, watering should be sufficient, so that the root system is in close contact with the soil and promote slow seedling. Nutrition cup sowing is not pseudo-planting, but there should be time seedlings in order to cultivate strong seedlings and full seedlings, usually after 2 times of seedlings, and finally leave 1 seedling in each cup. After dividing the seedlings, set up a sunshade net to protect against sun, cooling and rain.

Third, post-seedling management:

The key to management: temperature and moisture should be controlled before seedling transfer to slow seedling, light and nutrition should be improved before seedling growth, and seedling refinement should be carried out before planting to prevent overgrowth or disease in order to cultivate strong seedling.

Hot weather needs shading and cooling, sprinkling water once in the morning and evening every day. After slowing down the seedlings, in order to prevent overgrowth, water them once every morning. Three days after seedling retardation or the third true leaf stage, thin human feces and urine or 2% urea aqueous solution should be irrigated once to promote seedling growth. One week before planting, dung water or 2% urea solution should be irrigated again to meet the needs of seedling growth recovery after planting. If the seedlings grow, it is necessary to reduce watering and enhance ventilation and light transmission.

The common diseases and insect pests in seedling stage are quenching disease, Botrytis cinerea, hanging filaria, Pieris rapae, yellow koji jumping beetle and so on. In order to prevent the occurrence of diseases and insect pests, insecticide and fungicide are sprayed 3 times at seedling stage. Spraying can be arranged 3 days before seedling separation (or the second true leaf stage), 5 days after seedling retardation (or the fourth true leaf stage), and 3 days before planting. Fungicides can be used with 75% chlorothalonil wettable powder or 50% carbendazim wettable powder, etc., and pesticides can be used with 48% Lexben 1000 times or Bt emulsion 1000 times. When diseases and insect pests are found, the quenching disease can be controlled by spraying 75% chlorothalonil wettable powder or 50% carbendazim wettable powder. Botrytis cinerea can be sprayed with 50% Chlorothalonil 2 200 times or 5% propofol 1500 times. Hanging filariasis can be sprayed with 5% fipronil 3000 times or 1% insecticidal 3000 times from egg hatching peak to 2nd instar larvae. Pieris rapae can be sprayed with 1000 times of Bt emulsion or 1500mur4000 times of Shuding, while yellow striped beetles can be sprayed with 1000 times of Batan 1000Mel 2000 times or 48% of Lesbon 1000 times.

4. Effective ways to prevent excessive growth of seedlings and prevent excessive growth of seedlings at seedling stage:

1. Sowing should not be too dense, so as to avoid crowding of seedlings and emergence of tall seedlings.

2. Remove the ground cover in time.

3. Time seedling, false planting and colonization. After emergence, there should be time for seedlings, generally between seedlings 2 MUE 3 times. Seedlings should be divided (pseudo-planting) when they have two leaves, and the density of pseudo-planting should be controlled at 150 plants per square meter. if there are conditions, it is best to raise seedlings with nutrition cups.

4. Strengthen ventilation and light transmission, reduce temperature and temperature, and control the excessive growth of seedlings.

5. Carry out fertilizer and water management reasonably. In the allocation of nutritious soil, attention should be paid to the amount of phosphorus and potash fertilizer, the amount of nitrogen fertilizer and water leaching.

6. dilute seedlings should be discharged in time, and when overcrowding occurs, seedlings should be moved properly to separate large and small seedlings and increase the vegetative growth area of a single plant.