Key points of asparagus seedling raising technique

The main points of cultivation techniques of asparagus are introduced as follows: first, the selection of varieties is different from other vegetables. Asparagus is a perennial plant, and it can be harvested continuously for 15 years at one time. Therefore, the first generation hybrid varieties with disease and insect resistance, strong stress resistance, short dormancy period, good commodity, high quality and high yield should be selected. Second, raising seedlings 1. Sow seeds. Use 90,360 seeds per square meter. The suitable germination temperature of asparagus seeds is 25 ℃ ~ 30 ℃. The sowing time is from January to February in greenhouse, from February to March in sunny border, from late March to late April in small arch shed, and from late April to mid-August in open field. two。 Seed treatment. The seeds were soaked in 50% carbendazim 300 times solution (or 75% chlorothalonil wettable powder) for 12 hours; after being soaked in clean water, the seeds were soaked in 25 ℃ ~ 30 ℃ warm water for 24 hours, changing water once or twice a day, and scrubbing the seeds repeatedly to remove mucus, blighted seeds and impurities from the seeds. 3. Sprouting. The soaked seeds were wrapped in a wet cloth and germinated under the condition of 25 ℃ ~ 28 ℃. Rinse with clean water 1 / 2 times a day, 5% / 10% of the seeds can be sown. 4. Get the seedbed ready. Soil preparation and fertilization: per square meter, 3kg of high-quality mature organic fertilizer and 20kg of ternary compound fertilizer are applied into the soil. Planting and sowing: the width of the border is 1.4 meters, the length is unlimited, the ridge width is 0.2 meters, the greenhouse is 5 cm × 5 cm, the planting ditch is 10 cm × 10 cm, and the ditch depth is 2 cm to 3 cm. Cover the ditch flat after sowing and immediately water it thoroughly. Greenhouse sunny beds, small arch shed seedlings before sowing film, nutrition bowl (block) seedling each bowl (block) sow one seed, covered with nutrient soil 1.5 cm thick. 5. Seedbed management. The main results are as follows: (1) temperature: the suitable ground temperature is 15 ℃ ~ 25 ℃, the temperature from sowing to seedling emergence is 25 ℃ ~ 30 ℃, and the temperature from emergence to planting is 20 ℃ ~ 25 ℃. Try to heat up when it is lower than 15 ℃, and let out air and cool down when it is higher than 35 ℃. (2) Fertilizer and water: the bed soil was kept moist before emergence, and dry and wet after emergence. 7 grams of potassium dihydrogen phosphate and urea (1:1) were sprayed every 15 days per square meter with a concentration of 0.5%. Third, planting 1. Colonization period. Spring in our province is from late April to mid-May, and autumn is planted from late July to early August. two。 Planting density. Trench planting, row spacing 1.2-1.5 meters, plant spacing 25-30 cm, density 1500-2200 plants / mu. 3. The method of planting. The seedlings were planted in the middle of the ditch according to the plant spacing of 25 cm and 30 cm, and the rhizome disk was 10 cm from the ground. The direction of the underground stem is the same as that of the trench. The seedlings are planted on the same day and watered immediately after planting. 4. Post-planting management. Check and replenish seedlings in time after planting, combine with watering after planting for one month, and apply 5kg / mu urea after topdressing. Compound fertilizer was applied once every other month, and then increased by 1 kg / mu each time. In the whole growing season of asparagus, pay attention to ploughing and weeding, combined with ploughing many times to cover soil, covering soil height of 10 cm, into a turtle back-shaped high ridge, in case of waterlogging and timely drainage.