Cultivation techniques of green asparagus in greenhouse

Green asparagus is famous for its rich nutritional and medicinal value and is listed as one of the top ten famous dishes in the world. In recent years, Yifeng Agricultural Research Institute of Hejian City, Hebei Province has conducted an experimental study on the high-yield cultivation of mango bamboo shoots, and achieved successful technical experience, which is summarized as follows.

I. Establishment of high-standard greenhouses

Select the sandy soil plot with leeward to the sun, flat terrain, fertile soil, thick plough layer, convenient drainage and irrigation, and good ventilation to build a shed. The effect of daylighting with 5 degrees sun deviation from north to south is the best in the direction of the shed. The east-west length of the greenhouse is 50 meters, the span is 8.2 meters, the height of the back wall is 2 meters, the thickness of the wall is 1.2 meters, the top width is 0.9 meters, and the ridge height is 3 meters. The back slope is covered with 20 cm thick corn straw or wheat straw, the film is covered with 45 cm thick soil, the front slope is covered with polyethylene without dripping film, and a cold proof ditch of 70 cm × 70 cm is dug in front of the greenhouse, which is filled with corn straw or wheat straw.

2. Cultivation techniques

1. Variety selection. Green asparagus should choose the hybrid with cold resistance, disease resistance, scale clasping, green tender stem and sturdy and uniform.

2. Soak the seeds in warm water. Before sowing, soak in 45-50 ℃ warm water for 30 minutes, change the well water and soak for 24 hours, then drain, rinse once with 30 ℃ warm water, and accelerate germination at the temperature of 25-30 ℃. Rinse with 30 ℃ warm water every morning and evening, then wash away the surface secretions of the seeds to prevent mildew and rot. When the seed germination rate reaches 15% (germination to the degree of broken shell and whitening), it can be sown.

3. Sow seeds. Seedlings were raised in a small arch shed at the beginning of March. Nursery bed per mu greenhouse selection of 1.5 meters * 10 meter seedbed two seedbeds each 2.5 kg diammonium phosphate, 1.5 kg potassium chloride, and then turn the ground 20 cm, the seedbed flat, fine. First trench by row spacing 10 cm, ditch depth 5 cm, and then sow according to 10 cm plant spacing, 1 seed per hole, covering soil about 3 cm, sprinkle 1605 mixed wheat bran poison bait on the bed to eliminate underground pests. Then the small arch shed is covered with a layer of plastic film, which is strictly sealed and generally does not come out.

4. Seedbed management. Asparagus seeds can only germinate at more than 10 ℃, and the highest temperature is 25: 30 ℃. The temperature of seedling sowing in small shed is still low, and grass should be covered in the shed at night. When 60% of the seedlings top soil, the plastic film should be removed in time. After all the seedlings come out, they will be put on the air. The lookout should be covered after 11:00 and 2 p.m., and the vent will be from small to large. With the growth of bamboo shoots, all the greenhouse films were opened at last. During the seedling stage, the best temperature should be controlled at 20-25 ℃ in daytime and 18 ℃ at night.

5. Planting. In the first ten days of June, it can be planted when the seedling is 50 cm high, 3-6 roots and 3 tender stems. The seedlings of asparagus should be graded according to their size and planted separately. When transplanting, the sprouting surface of the root plate of asparagus should be to the south. Before planting, remove the residual branches and leaves of the recommended crops to prevent the occurrence of diseases and insect pests in the greenhouse. Apply sufficient base fertilizer, generally apply more than 7500 kg of farm manure, 50-70 kg of ternary compound fertilizer, 20 kg of urea and 30 kg of potassium chloride per mu. And ploughed the soil 20 centimeters deep and leveled it. From one side of the greenhouse in accordance with the north-south direction of the ditch, ditch depth of 10 cm, ditch application of Di Chong Jing and Di Jing each 3 kg, soil medicine mixed evenly, it can be planted according to the row spacing of 90 cm * 30 cm. After planting, it is required to cover the soil 3cm for the first time, and the depth of the soil for the second time is the same as that of the original seedling after 7 days and 8 days, and should be watered thoroughly after the first cover.

6. Post-planting management. The seedlings should be checked in time within 1 month after planting, and it is found that the dead seedlings should be replanted in time, and the requirement of replanting seedlings is larger than that of the original seedlings. After the seedlings were planted, the tender stems were drawn out in 7-8 days, because the seedlings were delicate and had poor resistance to diseases and pests, so they should be checked in time, and more than 800 times 50% carbendazim was sprayed in time when stem blight was found, and timely spraying and control of insect pests were found. One month after planting, the tender stem of the seedling has been 4 cm high. In order to promote its growth and development, sufficient water and nutrients must be given. At this time, quick-acting chemical fertilizer can be applied, 10 kg urea per mu, or 15 kg ternary compound fertilizer per mu. Before and after August 25, asparagus entered the autumn stage, and then opened ditches to pursue 3000-4000 kg of farm fertilizer, 10 kg of diammonium phosphate, 15 kg of potassium chloride and 40 kg of ternary compound fertilizer. Around October 25, cut off the stems of asparagus, remove all the remaining branches and leaves, take them out of the shed and burn them centrally. Then ploughing and loosening the soil, ditching and applying 40 kilograms of compound fertilizer and 20 kilograms of urea. In the middle of November, water was watered once, combined with ploughing and loosening soil, 4 kilograms of soil worm net and ground fungus net were applied, the ridges were arranged into the shape of fish back and covered with plastic film. In mid-December, cover the grass at night to keep the temperature in the shed at 20: 28 ℃ during the day and 18: 20 ℃ at night.

7. Harvest. When the top soil of the tender stem, break the membrane and release the seedlings in time. When the tender stem grows to 20 cm high, cut it off with a sharp bamboo shoot picking knife. The asparagus is casually put into the bamboo shoot box. After picking, the tender stems are arranged, graded, bundled, boxed, covered and sold with wet cloth. They can be temporarily placed in a cool place and must not be soaked in water to avoid decay.