Standardized cultivation techniques of asparagus

Water spinach, formerly known as Ipomoea aquatica, also known as rattan vegetable, Chinese cabbage, macaroni, arenaria, urn vegetable, empty cauliflower, bamboo leaf vegetable, festival vegetable. The stem center of the white trumpet-shaped flower is empty, so it is called "hollow cabbage". It is widely cultivated as vegetables in rural areas of southern China.

The morphological characteristics of 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. Leaves 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. The fruit is hollow and 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. Trailing herbs, smooth throughout. There is no root in the ground. The stem is hollow. Leaves alternate, elliptic-ovate or long triangular. Flowers are usually white, but also purplish red or pink. The seeds have fine hairs. The florescence is from July to September. Standardized cultivation techniques of asparagus

First, variety. ⑴ white flower species: long heart-shaped leaves, hypertrophic stems and leaves, light green, white flowers, tender texture, good quality. Such as big bone blue, big chicken white. ⑵ purple flower species: lilac stems and flowers, many fibers, poor quality, strong stress resistance. ⑶ Jian big-leaf water spinach: suitable for loam or clay cultivation, like nitrogen fertilizer, luxuriant stems and leaves, hollow nodes in stems, hypertrophic leaves, high yield and good quality, strong adaptability.

Second, site selection: spinach is suitable for humus-rich and moist soil, with strong branching, well-developed adventitious roots, rapid growth, high cultivation density, high harvest times, high yield and fertilizer tolerance. Therefore, we should choose sunny, fertile, water-source fields to plant. The effect of cultivation in protected soil is better.

Third, sow seeds. Direct seeding in the open field, seedling transplanting can be done, and the sowing time is generally in the middle and late April. Direct seeding on the ground can be done by strip sowing or on-demand sowing, with a row spacing of 30 cm and a hole spacing of 15 cm. Each hole has 3 to 4 seeds, which can be watered immediately after sowing, and seedlings can emerge about 7 days after sowing. They can also be sowed in secret and harvested when the seedlings are 17cm high. After sowing, cover with plastic film to increase temperature and moisturize, and remove the film after the seedlings are unearthed.

Fourth, planting and management. Asparagus is not strict on soil conditions, so it is appropriate to choose low-lying, moist and fertile clay soil for cultivation. In the early stage, the soil should be ploughed and loosened in time to raise the ground temperature. In summer, the temperature is high, the plant grows fast, the fertilizer and water demand is large, and the water should be watered frequently (dry air, insufficient soil moisture, which can easily lead to the increase of hollow cabbage fiber and affect the yield and quality), and combined with watering for topdressing. When the temperature turns cool in autumn, weeding and topdressing should be done in time, and attention should be paid to the control of red spiders and other pests. Asparagus harvest time is long, generally after each harvest, it should be combined with watering mu of ammonium sulfate 10 kg.

5. Field management: from cotyledons to 4-5 leaves, the suitable temperature is 20-25 ℃. The suitable temperature in the growing period of stems and leaves is 25-35 ℃, and the light conditions are not strict. There is a great demand for water and fertilizer, in addition to applying sufficient base fertilizer, but also a large number of topdressing, each picking topdressing 1-2 times, the concentration of topdressing should be light and then concentrated, mainly nitrogen fertilizer. Drought and lack of fertilizer will affect the yield and quality. The harvest of hollow cabbage, such as one harvest, the plant height of 12-15 cm can be interspersed with seedlings. If it is harvested many times, it can be pulled out and listed in combination with fixed seedlings when the plant height is 18-21 cm, and the row spacing is 12-15 cm. The seedlings left behind can be harvested and listed many times. When the plant height is 33 cm, the first picking begins, and two stem nodes are left at the base of the stem. In the second picking, the second segment left at the base of the stem was picked. In the third picking, the first stem left at the base of the stem was picked to reach the base of the stem to sprout again. In this way, the stems picked in the future can be kept stout. It is appropriate to pick by hand when picking, and it is easy to rust and die if you use iron tools such as knives to harvest.

Sixth, pest control: there are Plutella xylostella, red spiders, aphids, leaf rollers and other pests in hollow vegetables, which should be controlled in time. The disease is mainly caused by white rust, which can be controlled by spraying 1-D-1-D-1-1-D-1-D-1-

7. Harvest. Timely harvest is the key to high yield and high quality of asparagus. In production, it can be harvested when the seedling height is 20cm to 30cm. In the first and second harvest, there should be 2-3 nodes at the base of the stem to facilitate the germination of new buds, promote lateral branches and strive for high yield. After harvesting for 3 or 4 times, the plant should be reharvested, that is, there are only 1-2 nodes at the base of the stem to prevent the occurrence of too many lateral branches, resulting in weak and slow growth.