This paper summarizes the standardized planting technology of asparagus in Dingxi City, including the introduction of fine seeds, colonization management, field management, and pest control, in order to provide technical reference for asparagus cultivation in the region.
Dingxi City is located in the western edge of the Loess Plateau and the end of the West Qinling Mountains, the altitude is 1 640 ~3 941 m, the average annual temperature is 6.3 °C, the average annual sunshine is 2 500 h, the climate is cool in summer and autumn, the temperature difference between day and night is large, which is conducive to the accumulation of various types of vegetable dry matter, and the occurrence of diseases and insect pests is small, the degree of harm is low, and it has regional production advantages. Many vegetables in the region have local characteristics and significant market competitiveness advantages, such as Zhangxian leeks, Lintao lilies, Longxi edible mushrooms, and Celery in Anding District.
Asparagus young stems are fragrant and delicious, tender and delicious, flavorful and aromatic, containing a variety of amino acids and trace elements, with high nutritional health value, many diseases of the human body have a good prevention and treatment effect, is a high-grade nutritional health care vegetables, is listed as one of the "world's top ten famous dishes".
The introduction and planting of asparagus can enrich the varieties of summer vegetables in the Dingxi Plateau, and guide the local vegetable planting mode from extensive and large-scale to refined and high-grade development, which is of great significance to making the Summer Vegetable brand of the Dingxi Plateau bigger and stronger.
<h1 class= "pgc-h-arrow-right" >1 good seed introduction</h1>
According to the climatic conditions in Dingxi and the demand of the surrounding market, "Jinggangshan l" is a combination of green and white shoot varieties, with strong drought resistance, bright color and green color, good commerciality and high yield, which is currently an ideal choice of varieties.
<h1 class="pgc-h-arrow-right" >2 colonization management</h1>
< h1 class="pgc-h-arrow-right" >2.1 colonization period</h1>
The high altitude and low winter temperature in Dingxi region, due to the poor resistance of seedlings, the survival rate of cold and drought stress during the seedling lifting process should be started in mid-May in the spring.
<h1 class="pgc-h-arrow-right" >2.2 colonization method</h1>
Before planting, according to the ridge surface width of 80 cm, ridge ditch width of 30 cm, ridge height of 15 cm ridge ridge, and then covered with a width of 120 cm mulch film, strong and weak seedlings planted separately for field management. When planting, according to the row spacing of 110 cm and the plant spacing of 30 cm, planted along the center of the ridge surface, 22 500~30 000 plants/hm2. To achieve planting, watering, covering and other operations at one time, to water thoroughly, to ensure the survival rate. After the seedlings are slowed down, the planting holes should be filled flat.
<h1 class="pgc-h-arrow-right" >3 field management</h1>
<h1 class="pgc-h-arrow-right" >3.1 Management in the year of planting</h1>
3.1.1 Timely seedling replenishment After colonization, it is harmed by local climatic conditions, soil moisture, cordyceps, etc., resulting in different degrees of lack of seedlings and ridges. Therefore, it is necessary to make up for the lack of seedlings in time to ensure sufficient plant number and yield base, and to water through the seedlings after replenishment to ensure the survival rate.
3.1.2 Strong seedlings promote roots After planting, due to the short plant size, shallow root system, and poor water absorption and fertilizer ability, weeding should be cultivated in time. According to the soil moisture, timely watering, watering once every 10 to 15 days, the amount of watering should be wet through 25 cm deep soil at a time. During the flood season, water should be drained in time to prevent the dead seedlings from accumulating water in the field. After slow seedlings, 30 days after the seedlings, nitrogen, phosphorus and potassium compound fertilizer was applied to the ditch strip 20 cm from the plant on the side of the ridge ditch, and after fertilization, the water was watered, and the nitrogen, phosphorus and potassium compound fertilizer was applied to the ditch strip 225 kg/hm2 at 20 cm from the plant on the other side of the ridge ditch at 30 days, and the water was watered after fertilization. After colonization, about 75 d of seedlings were planted to produce the last batch of stems, 3 old and healthy female stems without disease and pests were selected, and the excess small stems were pulled out. After August, the rain in The Dingxi area increased, the temperature was 20 to 25 °C, and the asparagus entered a rapid growth stage. Autumn fertilization should be reapplied to promote the rapid growth of asparagus and lay the foundation for a good harvest in the second year. Generally, 15 000 kg/hm2 of organic fertilizer, 450 kg/hm2 of compound fertilizer and 150 kg/hm2 of urea are applied, and fertilization is opened on both sides of the ridge ditch at 40 cm from the plant and watered. After mid-October, the frost season in the area came, the stems and leaves of the asparagus aboveground withered, and the internal nutrients began to transfer to the underground roots. After all the aboveground parts of the plant have withered, the aboveground stems and leaves should be thoroughly cleaned to reduce the source of disease and pest infestation.
<h1 class = "pgc-h-arrow-right" >3.2 Management of bamboo shoots in the second year of planting and beyond</h1>
3.2.1 Scientific fertilization In March, germination fertilizer was applied at the same time as ploughing and cultivating soil between ridges, generally organic fertilizer 15 000 kg/hm2, nitrogen, phosphorus and potassium compound fertilizer 225 kg/hm2, to provide sufficient inorganic nutrition for the germination of phosphorus buds and the growth of young stems in spring; in early to mid-June, strong bamboo shoot fertilizer was applied, generally nitrogen, phosphorus and potassium compound fertilizer was applied 150~225 kg/hm2, and fertilized and watered along the ditch at 40 cm from the plant; after the end of the bamboo shoot harvest in early to mid-August, combined with the flat stubble cultivation soil, autumn fertilization should be reapplied. Generally, organic fertilizer 15 000 kg/hm2, nitrogen, phosphorus and potassium compound fertilizer 750 kg/hm2, and urea 150 kg/hm2 were applied to accumulate nutrients for the cultivation of high-quality and high-yielding young stems next year. This kind of three-fertilizer matching, rational operation and planning of the fertilization mode is the basis for the high yield and high quality of asparagus.
3.2.2 Watering at the right time Asparagus has a well-developed root system, weak transpiration effect, and is relatively drought-tolerant. To ensure good quality of young stems, high harvest times, and high commodity output, it is necessary to keep the soil moist during the harvesting period. Dingxi spring drought and little rain, according to the soil moisture conditions every 10 days of topdressing watering, each application of nitrogen, phosphorus and potassium compound fertilizer 120 kg/hm2, urea 45 kg /hm2, watering watering to each time through the soil 25 cm deep is appropriate. During the flood season, attention should be paid to drainage to prevent the occurrence of diseases such as rotten roots caused by difficulty in breathing in the root system.
3.2.3 Selection of female stems In the second year after colonization, new asparagus fields, because the root system is not very robust, the accumulated nutrient ratio is small, and it is only advisable to harvest green asparagus. Generally, the first young stem that grows in early April remains in the field as a mother stem and does not harvest, providing sufficient nutrients for the growth of young stems and roots in the later stage. Later, the young stems that grow out begin to be harvested and can be harvested until early to mid-August.
3.2.4 Timely plucking Of asparagus plants can reach more than 1 m, due to strong branching ability and dense foliage, which seriously affects ventilation and light transmission, and is prone to lodging. After entering the autumn, the rain increases and the air humidity increases, resulting in an increase in the incidence of pests and diseases. When the plant reaches about 60 cm, it can be decoyed, which is conducive to the delivery of nutrients to the underground part, promotes the growth of underground rhizomes, and can also reduce the incidence of diseases and insect pests.
3.2.5 Scientific harvesting of bamboo shoots In order to ensure the commercial characteristics of asparagus, green asparagus should be harvested before 10:00 and after 16:00. Tender stems that grow 20 to 24 cm above the ground are cut off close to the surface with sharp blades and sold in grades. During the harvesting period, it is necessary to water the soil at the right time to keep the soil moist, and the humidity should be held in a ball by hand and scattered after sowing, so that the young stems can grow fast, have good quality and have high yields.
<h1 class = "pgc-h-arrow-right" >4 pest control</h1>
<h1 class = "pgc-h-arrow-right" >4.1 Agricultural control</h1>
Focusing on agronomic measures to prevent can achieve a multiplier effect with half the effort. Specific methods are: increase soil organic matter, loosen the soil, and promote the development of asparagus root system. Increase the application of organic fertilizer and phosphorus and potassium fertilizer, appropriately control the amount of nitrogen fertilizer, promote the robust growth of asparagus stems and leaves, and improve disease resistance. After the end of the shoot picking period, the stumps and the mother stems on the ground should be eradicated, and thoroughly cleaned and burned in a concentrated manner, and the scale bud plate should be sprayed to sterilize and disinfect. In the autumn stage, the timely removal of field disease residues can greatly reduce the occurrence of diseases. After cleaning up the countryside to reduce the source of infestation, after all the aboveground parts of the plant have withered in winter, the stems and leaves on the ground should be thoroughly cleaned and burned in a concentrated manner.
< h1 class="pgc-h-arrow-right" >4.2 Disease control</h1>
Asparagus stem blight is a devastating disease in which water-soaked spots appear on the stems at the initial stage, gradually expanding into fusiform or linear dark brown spots, and finally long spindle-shaped or oval spots, with a central russet, depression, and many small black particles scattered on it. To control stem blight, 70% methyl tolbucin 600 times liquid or 70% methyl cream manganese zinc 600 times liquid can be sprayed alternately, sprayed once every 15 days, but spraying is strictly prohibited 15 days before harvesting.
<h1 class = "pgc-h-arrow-right" >4.3 Pest control</h1>
Asparagus pests are mainly ground tigers, caddisflies, grubs, golden needle worms, asparagus wood beetle moths, seed flies and so on. Granules such as cypermethrin, avermectin, and brassica thuringiensis can be applied in ditches to ensure that there are no pesticide residues at the time of harvest.