Cultivation and Management Techniques of Ipomoea aquatica in Greenhouse

Asparagus, formerly known as Yongcai, also known as rattan, water spinach, water spinach, arenaria, urn vegetable, empty cauliflower, bamboo leaf cabbage, white trumpet-shaped flower its stem center is empty, so it is called "hollow vegetable". It is widely cultivated as vegetables in rural areas of southern China.

Rabdosia angustifolia is a trailing plant with shallow root distribution, whisker root system and strong regeneration ability. Stem trailing, round and hollow, soft, green or lavender, stem 1-2 cm thick. The stem has nodes, each node in addition to axillary buds, but also can grow adventitious roots, Internode length of 3.5 to 5 cm, the longest up to 7 cm. Cotyledons opposite, horseshoe-shaped. True leaves alternate, smooth, entire, extremely pointed, veins reticulate, midrib obviously raised, leaves lanceolate, long oval or heart-shaped. The width of the leaf is 8 cm 10 cm, the widest is 14 cm, the leaf length is 13 cm 17 cm, and the longest is 22 cm. The petiole is longer, about 12-15 cm, and the longest is 17 cm. Hollow is concave, the fruit is a capsule, nearly round, the seed is dark brown, and the dry grain weighs 32-37 grams. Asparagus propagates by seeds or tender stems, while in the north it propagates by seeds.

Cultivation and management techniques of asparagus in greenhouse

1) sowing and raising seedlings

① nursery bed preparation: 20 kg of sifted farm manure and 50 g of diammonium phosphate are used in the seedling bed per square meter, spread evenly, turn shallowly, cuddle flat, and pour sufficient bottom water.

② sowing time: the early spring crop in solar greenhouse in North China can be sowed in early February.

Soaking seeds with ③ to accelerate germination: soak the seeds in warm water for about 30 ℃ for 12 hours, remove and control the excess water, and accelerate germination under 30 ℃. Rinse twice a day with 25: 30 ℃ lukewarm water to control the excess water and continue to sprout. It sprouts in 2 days and sprouts in 3 days.

Sowing seeds in ④: it is best to soak seeds and accelerate germination before sowing. During direct seeding, hole sowing was carried out according to the row spacing of about 35 cm and the hole spacing of 15 cm to 18 cm, with 3-5 seeds per point and 37.5-45 kg per hectare. Sow with 150 kg per hectare. If seedling raising and intercropping is put on the market, the seeding method is 30kg per hectare, and the seedbed is 750 square meters. After hole sowing or sowing, the soil is covered with about 1 cm.

⑤ post-sowing management: the temperature of solar greenhouse should be raised as much as possible after sowing, 30: 35 ℃ in daytime and more than 15 ℃ at night, pay attention to soil moisture conservation, and seedlings can emerge 5-7 days after sowing. Seedling height of about 3 cm began to strengthen fertilizer and water management, can be washed into urea and other chemical fertilizers, to keep the soil moist and adequate nutrients, avoid soil drought. Keep the daytime temperature at 25: 30 ℃. 30-40 days after sowing, the seedling height of 20cm can be pulled out and listed on the market or harvested. In order to accelerate the growth of stems and leaves, 20 mg / L gibberellin can be sprayed during the growth period, or spray Shibao (5 ml to 50 kg of water), or Yunda-120 (10 ml of 30 kg of water), once every 7 days and 3 times in a row.

2) colonization

① fertilization and soil preparation: select sandy loam with good permeability, apply high quality ring fertilizer 60000 kg per hectare, appropriate amount of phosphorus and nitrogen fertilizer, ploughing and raking fine to make a border, the width of the border is 1-1.2m.

② planting: seedling transplanting about 30 days after sowing, generally in the seedling height of 17cm 20cm, can be planted according to the row spacing of 35cm, 3 plants per hole, or plant spacing of 18cm, 2 plants per hole.

3) Field management

① temperature management: the temperature of water spinach production should be kept as high as possible. Generally, the temperature in the greenhouse should not exceed 35 ℃. When the temperature exceeds 40 ℃, it can be properly released around noon, and the minimum temperature at night should be kept above 15 ℃. In order to promote the growth of water spinach, a small arch greenhouse can be added to increase the temperature in the solar greenhouse during the low temperature period.

② fertilizer and water management: to strengthen fertilizer and water management after planting, it is appropriate to use quick-acting nitrogen fertilizer, but the dosage should not be large. Generally, about 150kg of urea is applied per hectare, and about 30 days after planting, the plant height is about 33cm. After harvest every 7 to 10 days, fertilizer and water management should be strengthened after each harvest, nitrogen fertilizer should be the main topdressing, 150 kg urea per hectare should be applied, while keeping the soil moist and promoting the occurrence and growth of new shoots.

4) harvesting

If it belongs to the indirect pull-out market, it shall be uprooted, cut off the roots and arranged into bundles. After fixing seedlings or planting, generally adopt the method of pinch harvest: the height of the plant is about 33 cm at the first harvest, leave 9-12 cm below to harvest the tender shoots on it, and then there are new shoots in the axils of the leaves, and when the new shoots are 15 cm long, the next round of harvesting will begin. However, during the first 2-3 harvest, 2-3 leaves should be left in the lower part to promote more new elimination and ensure high yield. In the future, 1-2 leaves should be left for harvest to prevent the occurrence of too many new shoots, weak growth and affecting the yield and quality. During the growth period, it is necessary to remove too many dense branches from the base in time, so as to achieve the purpose of renewing and maintaining a reasonable population. If it is harvested once by direct seeding, the yield will reach 15000kg to 22,500kg per hectare, and if it is harvested many times, the yield will reach more than 75000 kg per hectare.