The cauliflower planting techniques are as follows
1. temperature: sexual preference for warmth, aversion to heat, and intolerance to long-term low temperature. The optimum temperature for germination is 25℃, and the optimum temperature for growth is 20-25℃. The optimum temperature of flower ball growth is 15-20℃, and abnormal flower balls such as green flowers and hairy flowers are often produced when the temperature is above 25℃. 2. Sunshine: The plant grows well under sufficient light, but it can also withstand a slightly shady environment. Under direct sunlight, the flower ball often turns yellow and reduces its quality. 3. Moisture: Cauliflower has a large leaf area, but it is weak in drought and waterlogging tolerance. Excessive soil water content will affect the growth of roots and cause plant wilting in severe cases; If the soil is too dry, the plants will grow poorly, the flower balls will form ahead of time, and the balls will be small and of poor quality. 4. Nutrients: Cauliflower is a tall vegetable that needs both fertilizer and tolerance, especially nitrogen fertilizer. If phosphorus and potassium fertilizer are used properly, the plant can grow better. 5. Soil: Cauliflower needs sandy loam with deep soil layer, rich organic matter, good drainage and strong water retention. First, the cultivation techniques of spring cauliflower 1. Variety selection Choose varieties with strong cold tolerance and suitable for spring growth, such as Sheriya. 2. Seeding and seedling raising The method of seeding and seedling raising is basically the same as that of conventional cauliflower seedling raising, but the following points should be noted: seedling raising should be carried out in facilities and heat preservation measures should be taken. Sowing time1early February. It is best to sow directly in a nutrition bowl or a plug, and there is no need to divide the seedlings, so as to reduce the slow seedling stage of transplanting. 2. 1 seedling soil It is advisable to use artificially prepared nutrient soil, which is generally composed of garden soil and organic fertilizer with a ratio of 2∶ 1. Garden soil should choose plots that have not been planted with cruciferous flowers for more than three years. Organic fertilizer must be fully decomposed. A small amount of superphosphate or compound fertilizer can be added to the nutrient soil. When the soil is too sticky, about15% fine sand can be added to improve the aeration. The soil for prepare seedbed must be mixed evenly. Artificial nutrient soil has good soil structure, fertility, strong water retention, good aeration and few pathogenic bacteria, which is conducive to cultivating strong seedlings. 2.2 Sowing 1 1 late month to1early February, raising seedlings in greenhouse for overwintering, and each sowing date can be selected according to local conditions. Before sowing, the border must be leveled and stepped back and forth; The seedbed should be fully irrigated. After all the water in the irrigated bed seeps down, sprinkle a thin layer of sieved fine soil first, and then spread the dry seeds evenly on the border. Immediately after sowing, cover the sieved fine soil with a covering thickness of 5 times (about 0.5cm) and a uniform covering thickness of 3-4g per square meter. Cover tightly with plastic film immediately after sowing, and keep warm and moist at night. 2.3 sub-seedling (heel in) sub-seedbed generally adopts cold bed, and the bed soil is still suitable for nutrient soil. Cover the cold bed tightly with plastic film before seedling separation, and raise the soil temperature for 10- 15 days to improve the ground temperature of the seedling separation bed. When the seedlings grow to 3-4 leaves, divide the seedlings. When dividing seedlings, separate them according to different sizes, and the row spacing of the divided seedlings is 10cm× 10cm. In order to prevent the ground temperature from dropping due to flooding after seedling separation, the row spacing of seedling separation can be 10cm, after furrowing, the seedling water should be poured stably, and then the seedlings should be attached according to the row spacing of 10cm and covered with soil, and the next row should be carried out after filling. After the seedlings are delayed, the seedlings are cultivated and squatted. Conditional, can use the method of 10cm in diameter, which is beneficial to the protection of root system. After transplanting and dividing seedlings, cover with plastic film, cover with mulch at night, and keep warm to promote slow seedlings. Seeding directly in a nutrition bowl or hole plate does not need to be divided into seedlings. 2.4 Management of seedling stage Before emergence, heat preservation measures should be strengthened to promote the rapid emergence of seedlings, which should be controlled at 20-25℃ during the day and around 10℃ at night. After the seedlings come out, the bed surface is covered with fine soil with a thickness of 0.3-0.5cm to prevent the border surface from cracking and preserve moisture. When the cotyledons of the seedlings are fully spread, the seedlings should be thinned, the crowded seedlings should be pulled out, and 0.5cm of fine soil should be sprinkled to facilitate the growth of the root system of the seedlings and prevent the occurrence of damping-off at the seedling stage. When all the seedlings come out, the temperature of the seedbed should be properly reduced to prevent excessive growth, and it should be controlled at 15-20℃ during the day and around 5℃ at night. Attention must be paid to ventilation and cooling after the seedlings come out, otherwise the high temperature and high humidity environment will easily cause long-legged seedlings and affect early maturity and high yield. The temperature in the seedbed should be controlled at 15- 18℃, not higher than 20℃, and the lowest temperature should be controlled at 3-5℃. The temperature is achieved by the late uncovering and early covering of the mulch and ventilation, so that the temperature of the seedbed is within the suitable range for the growth of seedlings. When the temperature is high, the cover can be opened early and closed late, and the ventilation can be put on early and closed late, or even the ventilation volume can be increased; The sooner or later the mulch is uncovered, the amount of ventilation and the length of ventilation time should be determined according to the temperature, wind power and seedling growth. Ventilation should be increased a few days before seedling division to enhance the adaptability of seedlings to adverse external environment during seedling division. In order to promote seedling delay, heat preservation management should be paid attention to in the first three days after seedling separation, and the temperature of seedbed should be increased, but it should not exceed 30℃. After delaying seedling, gradually ventilate, and reduce the temperature appropriately. The temperature in the border should not exceed 20℃ during the day and not lower than 2℃ at night. Cover should be uncovered early and covered late to increase the light time of seedlings, and then gradually increase the ventilation rate to make the seedling growth environment close to the open field conditions. In order to enhance the resistance of seedlings to low temperature and dryness after planting and promote slow seedling growth, seedlings should be tempered at low temperature 15 days before planting. It is realized by gradually increasing the air discharge volume and closing the air outlet late. At the beginning, it is generally controlled at about 5℃ to prevent the seedlings from freezing. First, uncover the film on the top of the cold bed, cover it with grass at night, gradually remove the film and cover, so that the temperature of the seedbed gradually approaches the air temperature, and completely remove the film and cover 3 days before planting. When the seedlings grow to 7-8 leaves, water them thoroughly in advance. The seedling age is generally about 60 days. 3. It is very important to plant spring cauliflower in time. Early planting is easy to cause early blooming and affect yield; The quality of flower heads becomes worse when the planting is too late and the maturity is delayed. Generally, it is suitable for planting when the daily average temperature is stable above 6℃. When the local cold current begins to pick up, it is selected to be cultivated in the open field on a sunny morning. Planting density varies with different varieties in different regions, and it is generally appropriate to plant about 3500 plants per mu. Generally, autumn Chinese cabbage, radish, kidney bean and green onion stubble can be selected, ploughed and frozen, and decomposed chicken manure 1250kg per mu of base fertilizer can be applied. Sprinkle 50kg special fertilizer for vegetables before planting. Ridges are ridged to form a border, the width of the border is 0.8-0.9m, the height of the ridge is 0. 15m, a ridge is arranged in two rows, the spacing between plants is 0.4m, triangular bracts are fixed, and sufficient planting water is poured after planting. If plastic film mulching is used, plastic film should be covered on the border about 8 days before planting to improve the ground temperature. 4. Management temperature management after planting: The temperature is low and unstable when planting in early spring, and even there will be the influence of cold current. In order to promote slow seedling growth, the greenhouse should be closed for 3-5 days after planting, and ventilation should be started after slow seedling growth, and the ventilation volume should be increased from small to large, so that the temperature in the greenhouse is at 15-20℃ during the day and at 5- 10℃ at night. After planting 15 days, the ventilation rate will be further increased, and the ventilation opening will not be covered tightly. Generally, the shed film will be removed around early April. Timely ventilation, temperature control and timely shed removal after planting are the key to early-maturing cultivation of spring cauliflower in protected fields. Fertilizer and water management: the evaporation of water in the shed is not large, so there is no need to rush to water the seedlings. When the seedlings begin to grow again, intertillage in time to raise the ground temperature. Before removing the film 1-2 days, intertillage and water on sunny mornings, and the amount of water should be less. The depth of intertillage is about 3-4cm. When the heart leaves of the ring plants near the seedlings start to twist, urea10-/kloc-should be applied per mu. After heading, drill holes between plants to fertilize, and if possible, water 1 time every 5-7 days until harvest. 5. Fold the leaves and cover the ball, and harvest it in time when the transverse diameter of the flower ball is about 5cm (the size of an egg), break the outer leaves near the flower ball and cover the flower ball to avoid direct sunlight and keep the flower bud white. When the white flower ball is fully grown and not loose, it is the best time to harvest. Generally, the harvest benefit is high from late April to mid-May. (China Organic Agriculture Network)