Zucchini seedling raising combined with fertilization

Soil preparation and fertilization: zucchini likes slightly acidic soil, and the suitable pH value is 5.5-6.8. Zucchini is very strong fertilizer absorption, the application of too much nitrogen fertilizer, easy to cause excessive growth of stems and leaves, leading to falling flowers and fruits and diseases, fertilization should be nitrogen, phosphorus, potassium. In general, for every 1000 kg of fruit, it is necessary to absorb 3.92kg of nitrogen, 2.13kg of phosphorus and 7.29kg of potassium. The order of absorption of the five elements is potassium > nitrogen > calcium > phosphorus > magnesium. Soaking seeds to promote germination: first, put the seeds into clean water to remove the immature seeds floating on the water, then soak the seeds in 55 ℃ ~ 60 ℃ warm water for 10 minutes to kill the pathogen on the seed coat, soak in 20 ℃ ~ 30 ℃ warm water for about 4 hours, fish out, control dry moisture, wrap it with wet gauze, accelerate germination under the condition of 28 ℃ ~ 30 ℃, and sow seeds after breaking mouth and exposing. Sowing and raising seedlings: no matter using seedling bed or nutrition bowl to raise seedlings, it is necessary to prepare nutritious soil first, which is the key to cultivate strong seedlings. Take 3 fertile garden soils that have not been planted with melons in 4 years, a rotten circle fertilizer, add a small amount of firewood ash and sawdust, mix them evenly, sift them, and then make beds or install nutrition bowls. When ready, you can sow seeds. The overlying soil is 2 cm thick. After the completion of this process, a small amount of wheat bran mixed with methamidophos should be sprinkled on the border to control underground pests, and then use a small arch shed film to moisturize until seedling emergence. The standard of healthy seedlings of zucchini is as follows: the age of zucchini seedlings is about 30 days, it has 3-4 true leaves, the plant height is about 10 cm, the stem diameter is 0.5 cm, the petiole length is equal to the leaf length, the leaf color is dark green, the cotyledons are intact and the root system is well developed. Temperature management at seedling stage: the temperature during the day should be kept at 20 ℃ ~ 25 ℃, and should be ventilated and cooled when the temperature exceeded 25 ℃. The night temperature should be kept at 10 ℃ ~ 15 ℃, and the lowest temperature should not be lower than 6 ℃. During this period, it is necessary to scientifically and properly control moisture, and water can be watered with obvious symptoms of water shortage. after watering, attention should be paid to ventilation, lowering air temperature and preventing diseases. In order to prevent the occurrence of diseases such as standing blight and Fusarium wilt, a small amount of Wanku can be added to irrigate the roots twice; in order to prevent leaf diseases, methyl thiophanate or chlorothalonil can be sprayed every 7 days; in order to control the damage of greenhouse whitefly, aphids, cabbage worm and Liriomyza huidobrensis to seedlings, targeted drugs can be sprayed every 5-7 days to kill insects.