Asparagus High-yielding Cultivation Techniques and Introduction of Fine Varieties

Chapter 1 Overview

The scientific name of asparagus is Asparagus, which belongs to the genus Asparagus in the Liliaceae and is a herb for many years. The asparagus is called because of its main stem, the tender stems and bamboo shoots that resemble reeds. Therefore, many people in China nowadays have accustomed to call it Asparagus.
Asparagus is one of the ten most famous dishes in the world. It has a reputation as the "king of vegetables" in the international market. Its consumption in Europe is second only to tomatoes, beans, mushrooms and peas. In recent years, the cultivation area of ​​asparagus has been concentrated in the cold temperate zone to the global cultivation. Not only has it been sold out in the international market, it is in short supply, and it has become increasingly popular in the Chinese market. Production has developed very rapidly and it has become a kind of development in China. The foreground features a cash crop.

Section 1 Nutritional Value and Drug Value of Asparagus

In addition to its unique and delicious flavor, the asparagus has higher nutritional value than ordinary vegetables, fruits, and mushrooms. It was determined that every 100 grams of fresh asparagus tender stems contained 1.62-2.58 grams of protein, 0.11-0.34 grams of fat, 2.11-3.66 grams of carbohydrates, 1.2 grams of minerals, 0.7 grams of cellulose, and vitamin A, B, and C levels. Tomato and cabbage 1.8 times higher, also contains a variety of micro-organisms, such as selenium, manganese, molybdenum, chromium and so on. Regular consumption, can add protein, a variety of amino acids, vitamins and minerals.
As a kind of vegetable and food, the reason why asparagus has become a tight selling commodity in the domestic market is mainly because asparagus has a very good medicinal function. Studies have shown that eating asparagus can overcome human fatigue and have effects on hypertension, arteriosclerosis, heart disease, hepatitis, cirrhosis, nephritis, edema, cystitis, and other diseases, and have the function of treating leukemia. Long-term use of asparagus can help digestion, increase appetite, improve body immunity, reduce the toxicity of harmful substances, inhibit the vitality of cancer cells, prevent the production of cancer, and have a good anti-cancer effect.

Section II Economic Benefits of Asparagus Cultivation

Asparagus is a perennial, perennial herb. It differs from ordinary vegetables and crops in that it can harvest bamboo shoots continuously for many years after a single seeding, seedling raising, transplanting, and planting. The cultivation of asparagus does not require planting of seedlings every year. It not only saves money and labor, but also facilitates management. Asparagus production is developed. Except for the first year's investment in funds and labor, only fertilization is required from the second year. The labor input of pesticides and field management, and the harvest rate of bamboo shoots from the third year onwards. In areas where water and fertilizer conditions are relatively good and where technology is relatively high, annual harvesting of bamboo shoots can reach 800-1000 kilograms per mu, and individual high-yielding fields can reach 1200 kilograms, with an average of 600 kilograms of fresh bamboo shoots per acre. To protect the acquisition price of 4 yuan per kilogram, at least 2400 yuan per mu income, the input and output ratio of up to 1:4 in two years. The input and output ratio of general field crops or vegetables is about 1:2. Farmers generally believe that the economic income from planting asparagus is 5-8 times that of other crops.

Section III Prospects of Asparagus International Market

Europe and the Americas are the main areas for asparagus cultivation and consumption. In Asia, Japan is the main country for cultivation and consumption. Although the cultivated area of ​​asparagus in China is very large, most of the asparagus produced is exported for export, domestic consumption is still very small, only 3-5 million tons per year. China's asparagus canned products are mainly exported to Europe and the United States, and frozen and fresh. Asparagus is mainly sold to Japan, Hong Kong in China and some European countries. According to statistics, the number of asparagus required by EU countries has been increasing year by year, and prices have also increased year by year. Although the United States is one of the countries with large asparagus cultivation area in the world, However, about 100,000 tons are imported every year. At present, all countries in the world export asparagus from China and Spain. The export volume of the two countries accounts for about 80% of the world's total exports. The export price of canned asparagus in China is generally 1400-1800 US dollars per ton. After joining the WTO, the price of canned asparagus has increased, but it is necessary to increase the investment in science and technology and improve the quality of products in order to achieve its due status in the international market competition.


Chapter II Biological Characteristics of Asparagus

Section morphological characteristics of asparagus

1. The root system of root asparagus belongs to the fibrous root system, and the root group develops especially vigorously, with the characteristics of long, thick and many. After asparagus seeds are sown, the primary roots grow first as the seeds germinate, then the fleshy roots occur on the underground stems, and fiber roots reappear on the fleshy roots. As the age of the plant grows, the root system becomes larger. The asparagus root group is well-developed. In loose, deep soils, the lateral distribution length can reach up to 3.5 meters in length and up to 3 meters in the vertical direction, but most of them are distributed within 1.2 meters from the surface of the earth.
2. The stems of asparagus can be divided into three kinds: primary stem, aboveground stem, and underground stem. Newborn Stem: The first stem that grows out of the ground when the seed of the asparagus sprouts is called the primary stem. He is developed from the germ. Underground Stem: With the growth of seedlings, at the junction of the primary stem and root, projections form, forming bulbs, also known as underground stems.
3, leaves and quasi leaves in the asparagus stem with a pale green, thin film-like, triangular structures, asparagus has degenerate the true leaves, commonly known as scales. Commonly referred to as asparagus leaves. It's actually an abnormal branch. It is a cluster of 6-9 needle-like leafy branches clustered from membranous leafhoppers, vegetatively called leafy shoots or phylloids.
4. Flower Asparagus is a dioecious plant. Under natural conditions, the male and female plants are approximately equal. Female and male flowers were born in the leaf axils of female and male plants, solitary or clustered, and they were bell-shaped.
5. Fruits and Seeds Female flowers are fertilized and fertilized, and development results are real. The spherical berry resembling peas has a diameter of 7-8 mm and consists of peel, pulp, and seeds. The fruit is dark green when it is immature, gradually turning pale green, orange-green, orange-red, ripe red, high sugar content.


Section 2 Requirements of Asparagus on Environmental Conditions

1, the temperature adaptability of asparagus is very strong, both cold and heat-resistant, from the cold to the tropical can grow. However, the temperature has a great influence on the growth, yield and quality of asparagus. Therefore, it is suitable for the growth of asparagus in the temperate regions where the summer is warm and warm in winter. In tropical and subtropical regions where the temperature is high, asparagus plants do not sleep and grow continuously throughout the year with high yields. However, because of the high temperature, the respiration is strong and the consumption of nutrients is high. Stems and leaves are fast-growing, with more fiber stems and less quality. In winter cold regions, the underground part has strong cold resistance, and it can safely go through winter when it enters dormancy at -20°C. Asparagus seedlings can tolerate low temperatures of -12°C. The optimum temperature for seed germination is 20-25°C. When the soil temperature reached 10°C or more than 10°C, the stems of the reeds began to sprout. At 15°C, tender stems increased, but below 17°C, hollow bamboo shoots were easily produced. At 17°C to 25°C, the number of tender stems pumped was higher and the quality was the best. At this time, the harvested stems were more mature and tender. The sharp scales wrap tightly. At 30 °C, the amount of hairy stems was the most, and the growth rate was the fastest. At this time, the tender stems became fine, easily dissipated, easy to age, and bitter.
2. Light asparagus is a hi-light crop, and sufficient shoots are needed during the growth phase of shoots and leaves of the shoot to facilitate the production and accumulation of assimilation products. Insufficient illumination can seriously affect the growth and development of asparagus. Asparagus leaves degenerate on photosynthesis by quasi leaves, the leaves are needle-like, require longer sunshine and longer light, in order to meet the needs of plant growth and development.
3. Moisture cultivation Asparagus should be selected from lands with sufficient water supply and good irrigation and drainage conditions to meet the requirements for high yield of asparagus. The leaves of asparagus degrade into scales, and the stems are needle-like, and the surface has a layer of wax and the evapotranspiration of the plants. Smaller, asparagus also has a large root system. Storage roots contain large amounts of water and can regulate short-term water deficits. However, because asparagus absorbs the developed roots and the ability to play in the water is weak, it is too dry to cause asparagus production reduction. Asparagus is not tolerant to growth. If there is too much water in the soil for a long time, such as the groundwater level is too high, and the drainage is poor or the plots of water are often trapped, the oxygen in the soil may be insufficient, resulting in the death of the whole plant. In addition, if the air humidity is too high, in the event of high temperatures, it can easily lead to a large number of asparagus diseases.
4. Soil Asparagus is a perennial rooted underground stem crop, with huge underground stem squamous buds and roots. The development of root groups is very strong, and both physiological and respiration are strong. At the same time, asparagus roots have dual functions of absorption and storage. Root development depends mainly on the nature of the soil. To promote the development of the root system, we must choose a soil with good permeability. It is appropriate to use rich humus or sandy loam soils with rich organic matter. Asparagus requires slightly acidic to neutral soils, with a pH of 5.8-6.7, which should not exceed the range of 5.5-7.5.


Chapter III Fine Varieties of Asparagus

Asparagus is a perennial plant that has been cultivated for many years. The quality of the asparagus variety is directly related to the level of yield and the quality of the asparagus throughout its life cycle. In asparagus fields, seeds can be pollinated under natural conditions, but these seeds are severely differentiated and of poor quality and cannot be used for seeding. Asparagus varieties used in the production of asparagus at home and abroad are mostly single-crossed or double-crossed. In the past two decades, asparagus tissue culture technology has been widely used in asparagus breeding, which has accelerated the propagation of asparagus good varieties, and has used this technology to breed a large number of higher yield, higher quality, and stronger disease resistance. The excellent hybrid generation, polyploid and all-male asparagus new varieties have greatly promoted the development of the asparagus planting industry.
At present, asparagus varieties grown in China were imported from abroad for a long time, and there are many varieties and varieties. In particular, some second-generation species have seriously affected the yield and quality of asparagus. When selecting asparagus varieties around the country, it must be adapted to local conditions. Based on understanding the characteristics of varieties, it is planned and purposely introduced. It is imperative to avoid rigid introduction and blind introduction, resulting in undue losses. The following describes some of the asparagus varieties that have been used more in production and perform better. There are the following six kinds.
1. Grande: American California Asparagus Seed Co., Ltd., the newly introduced hybrid assortment of green and white asparagus varieties. Asparagus is large, neat, juicy, slightly sweet, tender, with low fiber content. The first branch height is 60 cm, the top scales are tightly coherent, and the head rate is still low at high temperatures. The asparagus is dark green, long round, waxy, and has good appearance and quality. It is extremely popular in the international market. Is the best variety of exports. Strong disease resistance, not susceptible to disease, high resistance to leaf blight and rust, high resistance to root rot and stem blight, immunity to asparagus shoulder bacteria II. The early stage of plant growth is moderate, and the growth period is strong in adulthood. There are many stem extractions, high yield, good quality, and the primary and secondary product rates can reach more than 90%. The output of adult bamboo shoots per 667 square meters can reach 1460-2000 kg.
2. Apollo (Apollo): A strong clonal clonal F1 hybrid that was bred by the American California Asparagus Seed Company. Moderate tender stems with moderate average stem diameter of more than 1.6cm, neat, delicate texture, and low fiber content. The first branch height is 56cm, with a tender stem and a fine tip. The scale buds are wrapped very tightly and the shoot tip is smooth and beautiful, and the head rate is very low at higher temperatures. The buds are dark green in color. The unearthed parts of the shoot tip and shoots of the shoots are slightly purple in color. The shoots are pointed and rounded. Both the appearance and quality are excellent, and it is extremely popular in the international market, making the quick-frozen export the best variety. Strong resistance to disease, high resistance to leaf blight and rust, high resistance to root rot and stem blight, immunity to asparagus latent II. The early growth potential of the plant is medium and moderate, and the growth potential is strong in adulthood. There are many stem extractions, high yield, good quality, and the primary and secondary product rates can reach 90%. In the second year after planting in the northern region, the yield can reach 400 per 667 square meters. 500 kg. The output of adult bamboo shoots can reach 1400-1800 kg per 667 square meters. Is currently promoting a new high-quality asparagus varieties.
3. Atlas: Two-hybrid species, with wide adaptability, conical green stems, moderate size, buds, bud tips, and bud bases are purplish, attractive in color and mild in harvest time In hot climate conditions, bamboo shoots are tightly packed. The stems are cylindrical, the stems are vertebral, and the stems are smooth. The tender bamboo shoots that can be obtained in early spring, the high resistance to fusarium, the asparagus resistant rust, and the high resistance to other leaf cercariae are immune to the asparagus latent virus II. force. The hybrid superiority of the variety is outstanding, and the yield is high. The single shoot weighs more than 26 grams, the branch point is about 60 centimeters, the stem is thick, the tip of the shoot is tight, the color is dark green, and the average diameter is about 1.8 centimeters. Green and white varieties, suitable for quick freezing, processing and preservation of the market.
4. Franklin: An all-male generation of breeds cultivated by asparagus breeding experts in the Netherlands, belonging to medium-maturing varieties. The species has a relatively strong growth potential, with relatively thick stems, medium and thick stems, uniform stem size, straight shoots, compact scales at the top of the stems, and green stems, beautiful stems, and yields of tender stems. It is highly resistant to root rot and stem blight, and has strong adaptability. The variety evaluation has been performed in a joint experiment. It is a high-quality, high-product variety popularized in recent years. This variety is suitable for white asparagus cultivation. Suitable for cultivation of green asparagus.
5. Jersey knight: Asparagus experimental breeding in New Jersey, USA. It is an all-female hybrid F1 hybrid that is both green and white. Its green shoots are thick and uniform green, uniform and consistent, accounting for 90 in diameter 1.4-2.0 cm. More than %, the top is round, the scales are tight, and the first branch height is more than 60 cm. The omni male cultivar is a new generation of high-yielding and disease-resistant varieties recommended by the International Asparagus Association in recent years. The third asparagus variety high yield test in the International Asparagus Association The follow-up yields of the male and female cultivars performed outstandingly. In the fifth year of production-production trials, the top ten were all male cultivars. Since all male cultivars accounted for more than 90% of the total, there was no significant consumption of nutrients for the production of seeds, so the potential for yield increase was After three years of exertion, it is generally more than 30% higher than that of the male-female blended species. Jersey knot production potential is greater. The fourth year's shoot field yields more than 2000 kilograms per 667 meters, and the disease resistance is increased by 46%. The older, the more significant the increase in production. Jersey has a strong resistance to disease, high resistance to leaf blight, rust, root rot, and stem blight, and is among the best in international asparagus resistance to stem blight tests, where a new base was established after planting. There is no need for medication in three years, and it has stronger resistance to disease than any other breed. The variety has good reality, strong resistance, and high plant growth. It can reach 2 meters high in two years, and has high accumulation rate of nutrients. Delicate, slightly sweet, less fiber content, good taste, is the best variety of international fresh asparagus market.
6. Extremely male imperial crown: a classic asparagus new product with strong advantages. The variety is cultivated in California, the United States, in the early maturing, suitable for planting north and south China. The scales at the top of the tender stems are tightly packed and the bamboo shoots are neat, with a high quality product rate of about 2.0 cm. With comprehensive resistance, strong root stocks, good tolerance, high yield and stable yield, it is a new variety of green ashes and asparagus, as well as a new generation of asparagus fine varieties developed in combination with our country's cultivation.
7. UC115: The newly introduced asexual hybrids in the United States have strong growth potential, high plant height, tight wraps around the stem, coarse and uniform, neat and consistent, high first branch and low head rate. Breeding period is short and early growth is good. Strong resistance, not easy to get sick, better than fertilizer water.
8, California 301 (UC301): California 301 is a hybrid generation of breeds developed by the University of California, United States, belonging to medium-maturing varieties. The cultivar is relatively tall, bamboo shoots grow vigorously and has strong adaptability. The head of the tender stem is conical, and the scales on the top of the stalk are not compactly coherent. It is easy to disperse in high temperature conditions in summer, and the yield is better. It is thick, with straight shoots, uniform and consistent green color, green stem color, tender stem base and head with purple, stem tenderness deformity, hollow less, better quality, medium disease resistance. This product is suitable for cultivation of white asparagus and is not suitable for cultivation of green asparagus.
9. Jersey Prince: The Prince of Jersey is a hybrid generation grown by the United States to increase breeding experts, belonging to medium-maturing varieties. The variety has a moderate growth trend and strong adaptability. The tender head has a conical head and high yield. The thickness of the stem is even and uniform. The average stem weight is 18.1-19.9 g and the disease resistance is medium. This variety is suitable for white asparagus cultivation.

Chapter IV Asparagus Breeding Techniques

The propagation of asparagus includes the seedlings ramets method, seed seedlings, and tissue culture propagation. Because the ramet method requires that the seedlings grow for a long time, the ramets are laborious, time-consuming, the seedlings of the ramets have less root systems, and the roots are severely damaged. After the fixed value, the growth is slow, the growth is weak, the yield is low, and the lifespan of the shoots is short. This is not suitable for field production. Use this method to breed.
The rapid propagation of tissue culture is only used for the expansion of precious varieties and cross-breeding parents. The cost is high and the application price in production is difficult to accept.
Seed propagation method is widely used in production. The seedlings are easy to transport, the propagation coefficient is large, the root system is good, the seedlings grow strong, the yield is high, and the longevity of harvested bamboo shoots is used. The seed propagation process is divided into two modes: direct seeding and seedling transplanting.
In live cultivation, comprehensive evaluation is more harm than good, and the advantage lies in strong live growth, large growth in the year, rapid growth of clusters, early gardening, and high yield of first shot shoots, but the main disadvantage is the large direct seeding amount, seedling management. Difficulties, low emergence rate, it is difficult to guarantee a complete seedling.
Transplanting seedlings has more advantages than directly. First, the high seedling emergence rate can save seed use and reduce costs. Second, intensive seedlings are easy to manage, and seedlings are quickly and neatly prepared. This helps control pests and diseases and cultivate strong seedlings to achieve early high yields. Third, seedlings can be cultivated Asparagus growth and development direction for directional colonization, to facilitate ridge cultivation, shoots and other aspects of management. Seedling raising and three ways: First, open field nursery, second, small plastic shed nursery, the third is Yangshuo nursery, localities can be selected according to the local natural conditions and the needs of the nursery period.

We mainly introduce plastic small arch nursery:

The first quarter plastic small arch nursery

At present, asparagus cultivation is generally adopted in small plastic arch nursery. It has the advantages of good temperature and moisture retention, easy construction, and low cost. It can grow seedlings more than 30 days earlier than open field, and the yield is obviously increased. It can lay a good foundation for the early high yield of asparagus.
1. Selection of nursery land The nursery should choose loose soil, fertile soil, good loam or sandy loam. At the same time, the seedlings must also have irrigated conditions and facilitate drainage. There is no monsoon hazard and the environment is empty and ventilated.
2. The time for raising seedlings is to extend the annual growth period of reeds. We generally use small arches to raise seedlings in the middle and early March.
3, the method of raising the seedlings deep to turn about 25 cm, per acre applied into a good rot 3000-5000 kg of fertilizer, nitrogen, phosphorus, potassium and 15% of the compound fertilizer 50 kg, and the soil mix well and mix into a nutritious The cultivation of the soil, and then made 1.2 meters or 1.5 meters of pupae, require the pounding surface, the soil is finely crushed, should be placed in a ditch for irrigation, planting white asparagus with an amount of 60 grams per acre, nursery area 20 - 30?, the amount of green asparagus per acre is 75 grams, and the area of ​​nursery is 30-40?. If you use nutrient sports seedlings, the effect is better. When transplanting, it is easy to raise seedlings, lighten the roots, and increase the survival rate of transplanting. However, due to the heavy workload and time-consuming, large-scale nursery is not suitable for this method.
4, soaking seed germination asparagus seed skin thick and hard, outside the wax paper, direct seeding is often not easy to absorb water germination. Therefore, germination must be done before sowing. The method of germination is: the seeds are first rinsed with fresh water, rinsed to remove fleas and insects, and then soaked in 50% carbendazim 300 times for 12 hours. After disinfection, seeds are soaked in warm water of 30°C-35°C. 48 Hours, changing water 1-2 times per day during soaking. After the seeds can fully absorb moisture and expand, the seeds are filtered out, placed in pots, covered with a damp cloth, and germinated in an environment of 25° C.-28° C., and washed with water twice a day. When the seeds have about 10% radicle whitening, they can be sown. It should not be too late to sow, otherwise it will break the radicle easily. Asparagus seed germination has a close relationship with temperature, and the optimum temperature for seed germination is 25°C-30°C.
5. Seeding method Before sowing, firstly fill the bottom surface with water. Scribe every 10 cm of the row spacing. Precipitate the seeds and sow the seeds in the center of the grid. Then apply 4-5 kg ​​of phoxim particles per acre. In a fine sieve, the soil shall be sieved evenly on the surface of the bowl, and the soil thickness shall be 2 cm.
6. To grow the shed cover film in early spring In order to raise the ground temperature, the cover film shall be made immediately after sowing. The control temperature in the arch shed shall be 25°C-28°C and 15°C-18°C at night. After the seedlings are brought together, the temperature changes in the shed must be observed constantly. When the temperature in the party shed exceeds 30°C, both sides of the shed must be uncovered, and the ventilation and hardening of the seedlings should be carried out, and the film should be gradually removed to prevent flashing caused by excessive filming. Loss suffered. When asparagus seedlings grow more than 3 stems above ground, they can be ready for colonization.

Section 2 Management of Seedbed Asparagus seeds differ from other crop seeds in that they take a long time to germinate. During seed germination and seedling growth, it is sensitive to conditions such as temperature, light, and water and fertilizer. Therefore, the focus of seedbed management is to meet the requirements of these conditions for seed germination and seedling growth as much as possible, so as to achieve the purpose of cultivating strong seedlings.
1. Control suitable seedbed temperature Asparagus is a thermophilic vegetable. Early and late seed germination and seedling emergence speed, depending on the temperature inside the chamber. If open seedlings are used, seed germination and seedling emergence are faster due to higher temperature at the time of sowing. The use of Yangshuo and small arch shelter seedlings, because the temperature is still low when sowing, and climate change, so the seeds sprout late, unearthed slowly, according to experiments, when the ground temperature is 15 degrees Celsius, germination requires 24 days; 20 degrees Celsius takes 15 days; When the local temperature reaches 25 degrees Celsius, it only takes 10 days. The current temperature is low, and the seedling period is elongated. The consumption of nutrients stored in the seed is increased, and the seedling growth is weak. In order to raise the temperature inside the seed to promote seed germination as soon as possible, during the seed germination, be sure to cover the strict plastic film, can not breathe wind, straw, mane hair and other covering materials should be properly covered, late exposing, in order to maintain a higher night Temperature, during this time, the temperature inside the chamber is best controlled at 25-28 degrees Celsius during the day. After unearthing, the shoots begin to undergo photosynthesis as the tips of the shoots spread out and the formation of branches, gradually turning from autotrophic to heterotrophic. Ventilate with seedlings. When using arch shelters, the membranes were initially ventilated on the south side of the loquat, and then the two ends and the north side were gradually opened to increase the ventilation. Finally, all the films were removed. During the growth period of seedlings, appropriate early uncovering and late cover are needed to extend the seedling illumination time, which is conducive to the cultivation of strong seedlings. During the growth period of the seedlings, the controlled temperature is: 25°C - 28°C during the day and 15°C - 18°C ​​during the night.
2. Apply timely fertilizer to promote the growth of seedlings and cultivating strong seedlings. When the seedlings extract the second tender stem, a nitrogen, phosphorus and potassium compound fertilizer should be topdressed, and the standard rice bran should be 33 square meters, followed by compound fertilizer 1.5. Kilograms should be watered immediately after application to facilitate the exertion of fertilizer effect. After the first 20 days after the fertilizer, a total of 2-3 times to ensure the healthy growth of seedlings.
3. During the growth of asparagus seedlings during drought-proof flood seasoning, the root system is shallow and sensitive to moisture. When water is lacking, the seedlings grow slowly, even though the stems are yellowish. Therefore, it is necessary to water the drought timely. Asparagus is not tolerant to stagnation, and it is most resistant to water in bed and seedlings, which can cause root rot and cause diseases. Therefore, after the rain, it is necessary to pay attention to the seedbed and timely drainage.
4. The single-on-demand seeding of the asparagus asparagus in middle tillage and weeding is less in density, and the seedlings in the early stage grow to breed weeds. Weeds not only compete with the secret seedlings for fertilizer, water and sunlight, but also cause diseases and pests to occur. Therefore, it should be promptly removed. Do not injure the seedlings when removing weeds. Watering or fertilizing timely scratching loose soil, to avoid seedbed soil compaction, in order to facilitate root development and seedlings robust growth.
5. Prevention and control of pests Asparagus seedlings are vulnerable to attack by tigers, mites, cockroaches and other pests during the growth period of their seedlings, resulting in seedling deficiency. Therefore, we must pay attention to inspection and prevention. In the late stage of seedling growth due to high temperature, high humidity, easy to infect stem blight and brown spot disease, should be sprayed once every 7-10 days, the main agent is 30% of the double Kyrgyzstan, 50% of carbendazim, 50 % of Lufeng and 80% of Mancozeb.
Chapter 5 Planting Techniques Section 1 Selection of Planting Fields Planting fields are critical to the growth and development of asparagus. Therefore, it must be carefully selected. To choose fertile soil, thick soil layer, strong fertilizer and water retention performance, good permeability, low groundwater level, easy cultivation of asparagus soil drainage, but sandy loam soil and light industry clay loam is most suitable. Sandy loam and light loam soil are not easy to compact, earth-cultivation and harvesting are convenient, and the harvested tender stems are white and not easily bent.
Former crops are mulberry orchards, orchards, and woodland should not be planted with asparagus. Because the roots of the soil remaining in the soil are prone to purpura, the root rot occurs easily if the asparagus is cultivated. It is also not suitable to cultivate asparagus on heavier lands where wheat is heavily eroded.
For the cultivation of asparagus, the groundwater level must be low, and the water conservancy facilities must be fully equipped so that the drought can be poured and the water can be discharged.
The soil pH is preferably 5.5-7.5. Do not grow asparagus on strong acid or strong alkaline soil. Otherwise, the growth of plants will be adversely affected. The soil salt content should be below 0.25% to facilitate the vigorous growth of asparagus.
For the cultivation of asparagus, the light conditions are better for plant photosynthesis. Since asparagus is tall and thin on the ground, do not grow asparagus on the tuyere to prevent the wind from blowing down the ground. The planting fields should be concentrated into one piece, with convenient transportation, easy management, acquisition and processing.
Section 2 Preparation before Planting
1. The long-term growth of asparagus in deep-sloped land preparation requires that the land be fully ploughed and leveled before it is planted, and sufficient basal fertilizer should be applied to fertilize fertility to lay a good foundation for the high yield of asparagus.
2. Before digging, fertilizing, fertilizing, and planting land, deepen the leveling land, white bamboo shoots shall be placed at a 1.8-meter spacing, and green bamboo shoots shall be arranged at a spacing of 1.3-1.4 meters. According to the topography, the north-south direction or the east-west direction shall be a straight line, and then Straight line digging 0.45 meters, depth 0.4-0.5 meters of planting communication.
When digging trenches, more than 25 cm of mature soil and 25 cm of raw soil should be divided. When backfilling, the ripening soil is placed at the bottom to facilitate the development of the asparagus root system. 3000-5000 kg of soil miscellaneous fertilizer and 50 kg of nitrogen, phosphorus, and potassium compound fertilizer per acre were applied to the planting trench. There are some requirements for the organic fertilizers in the planting communication. It is advisable to use decomposed pigs, chicken excrement and human excrement. Colony communication should not be filled in, and it can be 5-7 cm lower than the original ground. After the planting, the communication will be gradually filled. The planting communication should be filled with water to prevent sinking of the soil due to watering or rainfall after planting, so that the seedlings fall down. The ridge surface between the two communications should be made into a small arch with a middle height and low sides. Afterwards, with the continuous growth of seedlings, the ridge surface soil is gradually backfilled into the planting communication to form a soil ridge above the height of 10 cm. In order to make the leak drained and prevent flooding. Due to the deep roots of asparagus, if the planting communication is not digging, if the plowing soil below 25 cm is compacted with poor air permeability and nutrient content, the root system of asparagus is not easy to grow and the root plate spreads slowly, which seriously affects the early yield of asparagus.
3. The seedlings are graded and colonized in order to ensure that the asparagus grows neatly after colonization, and the seedlings are cut into pieces of soil by 10 cm square to facilitate soil transplanting. The seedlings should be graded when planting, and seedlings should be selected according to the seedling size. The standard for planting seedlings is to require seedling height of about 0.3 meters, with more than 3 stems and 7 underground storage roots. Failed to colonize.
The third quarter of planting time in accordance with the requirements of early high-yield cultivation techniques of asparagus, early spring using a small shed to cultivate seedlings, when the seedlings on the ground more than three stems, generally in the late May can be directed colonization. Seedlings with open seedlings can be planted in autumn or in the spring of the following year based on the seedlings. Irrespective of the method used to raise seedlings, in order to extend the growing period of asparagus field, the survival rate of directional planting with strong seedlings with soil blocks is high when planting. From this period, the seedlings are easy to carry soil, light rooting, quick seedling growth, and good growth. Large seedling root system, seedlings easily injured roots, susceptible to disease after planting. Age of 60-80 days is appropriate.
The rationality of the density of planting densities in the fourth quarter is related to the output, quality and length of harvested bamboo shoots and the convenience of management. The high density of planting has certain benefits for the early yield of asparagus, but with the expansion of the asparagus bulb body year after year, the increase in the number of bulb clusters will cause growth on the ground, poor ventilation and light transmission, and will easily lead to the occurrence of diseases and insect pests. The density of colonization is too small to use land, the yield is not high, and the economic benefits decline. The reasonable density is to maximize the yield and quality of the tender stems, and it can produce high yields for many years. The spacing of cultivated white asparagus is 1.8 meters, the spacing between the rows is 0.25-0.3 meters, and 1300-1500 plants per acre are most suitable. As the green asparagus cultivation is not required by the soil, the row spacing can be reduced to 1.3-1.4 meters, and the plant spacing is also 0.25-0.3 meters. It is more appropriate to plant 1600-2000 plants per acre.
Section 5: Method of colonization In the middle of the whole planting communication, draw a straight line, and then the seedlings with clods will be oriented and colonized according to the growth and development direction of the shoots of the asparagus seedlings. There should be more than three underground stems for planting seedlings. If the plants are planted in the north-south direction, the first stem (short and thin stem) to be extracted in the first place should be placed in the north, and it should not be placed on both sides of the furrow; The stems of the ground that were taken out for the first time should be placed on the east or west side of the ditch so that they are consistent with the direction of planting. Large seedlings are separated from the seedlings. Do not mix plants so as not to affect the uniformity of the asparagus. Planting time along the line by plant spacing 0.25-0.3 meters, with the digging planting. The size of the burrow should be the standard for putting seedlings into it. After planting, cover the soil with 4-5 cm and press it, then water it. With the growth of bamboo shoots, the soil will be gradually filled with planting trenches to maintain the depth of the seedlings at about 12 cm. When planted too deep, it is easy to cause lack of plants or make the seedlings poorly developed. The planting is too shallow, the plants are malnourished, the stem above the ground is easy to fall down, and the yield is not high.
Section 6 Field Management after Planting The length of time required for asparagus to grow from bamboo shoots to bamboo shoots varies greatly depending on the type of nursery and the timing of planting. The first year of nursery, planted in April of the following year, can grow for 5 months; Yangshuo nursery, planting from May to June can also grow 3-4 months, these two types can shoot bamboo shoots in the second year of spring, and The yield is relatively high; in spring, the seedlings are exposed in the open field, and bamboo shoots cannot be harvested in the spring of the second year after planting in August.
1. Supplementing seedlings and pest control shall be conducted within one month after the planting. When filling seedlings, sufficient water should be poured to ensure survival, and the seedlings of supplementary plants should still pay attention to directional planting.
The seedlings after planting have poor resilience and poor regenerative ability. For example, stem blight and underground pests will cause serious losses once they occur. Must constantly inspect the field, find pests and timely prevention and treatment.
2. Watering and cultivating soil should be promptly watered after colonization, and then cover with soil after water infiltration. When the soil is covered, it is necessary to break up the soil and prevent it from falling over. This is because the bamboo shoots are very small and must be carefully managed.
The asparagus seedlings after planting are shallow and have weak drought tolerance. Water should be properly watered depending on weather conditions and changes in public opinion. After each top dressing, water should also be applied to promote decomposition of the fertilizer and to exert its fertilizer effect. Autumn is the period of autumn stemming of asparagus, and it is also the critical period for the accumulation of nourishing yam to achieve high yield in the second year. In case of autumn drought, timely watering will affect the extraction of young stems and lead to premature plant failure. Pre-winter winter pre-winter season before and after pouring winter water, in order to facilitate the safe asparagus overwintering, and cultivate soil 15 cm to reduce the number of hollow bamboo shoots in the coming year.
3. Top-dressing seedlings will enter the normal growing stage after 20 days of colonization. At this time, quick-acting nitrogen fertilizers such as urea or ammonium bicarbonate should be topdressed to prompt the seedlings to quickly draw stems from the ground. Increase the amount of growth on the ground. At this time, 30 kg of urea or 50 kg of ammonium bicarbonate is applied per acre. When the fertilizer is applied, it should be communicated with the asparagus 20-25 cm along the ridge and ridge, and the communication depth should be 10 cm. It is appropriate to apply the fertilizer into the communication and timely cover the soil. When topdressing, prevent the fertilizer from being scattered on the ground or the fertilizer is too close to the plants to prevent the nutrient from popping or burning the plants. Water the fertilizer timely after applying fertilizer.
The 40th to 50th day of planting should be followed by the second autumn fat. At this time, the first time the fertility has passed and the peak of the first batch of tender stems has been inflicted. The second batch of tender stems will be issued for publication in a timely manner. The second autumn fat will make shoots grow robustly and germinate more. The top dressing was mainly compound fertilizer. Supplemented by nitrogen fertilizer, each acre can recover 40 kg of nitrogen, phosphorus and potassium compound fertilizer, and 10 kg of urea to ensure the need for fertilizer before the asparagus grows. It is necessary to maximize the development of autumn and accumulate more assimilation materials. The annual production will lay a solid foundation. After the first fertilizer, it must be watered in time.

Chapter 6 Harvesting of Asparagus and Field Management Asparagus after the second year of planting is the prime time for the production of asparagus. The quality of field management is directly related to the growth period of asparagus and the annual harvest. Yield.
Harvest of asparagus in the first quarter
1. The initial period of harvesting bamboo shoots is in accordance with the general management requirements of the cultivation techniques, which are usually the first year of early spring seedling cultivation, the summer season planting, and the second year of small-scale harvesting. However, the open field is my sowing seedling and the asparagus planted in the autumn. Due to the short growing season, the spring of the year is generally not suitable for harvesting or the yield of spring bamboo shoots is low. It is practicable to adopt bamboo shoots from the stem of the mum.
2. Preparing bamboo shoots
(1) Clear Garden is to remove stubble and fallen leaves of the asparagus and remove the overwintering mother stems before harvesting bamboo shoots, and to disinfect soils with heavier diseases in the field. The purpose is to facilitate the cultivation of bamboo shoots and prevention of pests and diseases. Clearing gardens are usually carried out after thawing in early spring, which can prevent the adverse effects of low temperatures in winter on the underground parts of asparagus; in addition, the earth-inlet parts of the asparagus stems that have been left are beginning to rot and are easily removed. When clearing the garden, the roots of the asparagus were removed one by one, and they could not be cut with a knife to prevent the occurrence of disease caused by the shoots. Also, it was not possible to plan with a hoe so as to avoid planing off the overwintering shoots on the bulb. The plucked stalks were burned together.
(2) After loosening the soil and disinfecting the garden, it is necessary to timely remove the loose soil, and then level the ground to prepare the ridge. If the disease of asparagus is serious in the previous year, soil disinfection should be carried out by spraying 50% of the whole asparagus on the ground, 400 times of double Jisheng, 30% of double Ji 800 times or 50% of Carbendazim 300 times.
(3) Fertilizing and culturing ridges to soften shoots is an important measure for the cultivation of white asparagus. During the harvesting period, the shoots are not allowed to grow to the ground, but the roots are still active. As the ground temperature continues to rise, the ability of the roots to absorb nutrients also increases. As long as the asparagus shoots are extracted, the nutrients stored in the roots of the fleshy roots are far from sufficient, and they need to be supplemented by sub-fertilization. Among them, the compound fertilizers with nitrogen, phosphorus and potassium contents of 15% each had the highest yield. In the poor fertility of the shoot field, the effect of top dressing is better, and the yield increase effect of top dressing in the later shoot shoots is more obvious. The top-dressing measures during harvesting should be applied flexibly according to soil fertility and management level. During the shoot-up period, top-dressing fertilizers should be quick-acting fertilizers and inorganic fertilizers. It is not advisable to top-dress fertilizers that have not been fully decomposed.
In spring, before the asparagus tender stems grow out of the ground, the soil should be used as a ridge, so that the time for the tender stems to be ridged depends on the climatic conditions. The cultivation of ridges is too early and the temperature of the soil rises slowly, delaying the timing of the tender stemming; Generally, when the soil temperature is 10 degrees Celsius below the depth of 10 centimeters in the underground, 15-20 minutes before harvesting shoots is appropriate. The cultivation of ridges is once or several times. If asparagus is cultivated and ridged, the soil layer is thick and the soil temperature rises slowly. Graduate ridges, each time about 10 centimeters of soil, once the soil temperature is raised, it will be cultured once, and finally it will be cultivated into standard soil ridges.
The ridge soil is moist and the soil is too dry or too wet to be suitable. When cultivating ridges, the soil should be taken 0.4 meters away from the asparagus bulb to avoid damage to the asparagus root system. When soil is used, the bricks, tiles, and stones in the soil shall be picked, the soil pieces broken and smashed, and the ridges shall be cultivated so as to prevent the bending deformation of the hard block when the tender stems are drawn out. Peilong will seriously affect the production of asparagus. Because the nutrition accumulated by asparagus is stored in the storage root, and the storage root is longer, generally 1-2 meters, and the life span is longer, about 4-5 years, once the ridge is broken, there will be a lot of nutrition. It was left in the soil to reduce the supply of asparagus nutrients, resulting in the previous year's nutrient accumulation can not fully play a role in affecting yield.
The size of the earth ridge should be based on the age of the shoot and the growth of the asparagus. Generally grown bamboo shoots, ridge width can grow well, young bamboo shoots and poor shoot growth can be smaller. In short, we should gradually widen the earth ridge according to the growth of the age of the bamboo shoots. The height of earth ridges should be determined according to the canning plant's requirements for the standard length of the raw materials. Usually the shoots produced are 1-2 cm longer than the raw material standards. If the raw material requires a net length of 18 cm, the height of the ridges should be from the root stem surface It is 25 centimeters to the top of the ridge, because it is necessary to keep 2-3 centimeters when harvesting bamboo shoots to protect the bulb from damage. The stalks are harvested when they are 1-2 cm away from the country in the ridge, so that they do not reduce production due to lengthening or shortening. Regardless of the age of the shoot, the growth of the plant is good and the height of the ridge is the same.
3. Shooting time, tools and methods of operation
(1) White bamboo shoots, bamboo shoots, bamboo shoots, bamboo shoots, bamboo shoots The bamboo knife is an iron-tailed blade with a blade length of about 45 cm. Sheng bamboo shoot tools can be used as basket tools or bamboo baskets, but also cartons can be used to prevent the shoots from damaging the shoots. It is best to sew a plastic film in the basket to maintain the freshness of the shoots and avoid the sun.
(2) The harvesting time is due to the easy lightening of the asparagus's tender stems. Therefore, white bamboo shoots should be harvested in the morning and in the afternoon.
(3) Take bamboo shoots carefully. Observe along the ridges of the soil. Open the soil on the side of the ridge with cracks or mounds uplift. Be careful not to bump the bamboo shoots and other shoots. When the width is 5 to 7 centimeters wide, until the tip of the bamboo shoots is exposed, the left hand pinches the upper end of the tender stem, and the right hand picks up the bamboo shoot blade. According to the requirement of the length of the harvested tender stem, insert the soil and cut off the tender stem quickly and put it into Sheng. Shoot inside the container. When cutting bamboo shoots, the movement should be accurate, stable, and the cutting surface should be flat. Staying too long will cause the bamboo shoots to rot in the soil and cause lesions. Keeping the bulbs too short will damage the bulbs and affect the overall yield. After the bamboo shoots are harvested, they must be backfilled and cultivated in time, which is consistent with the original soil ridges. Loose or tight filling of the bamboo shoots can cause deformation of the tender stems in the ridge. To prevent the collapse of ridge earth due to shoots or rainfall, etc., earth should be added at any time to keep the earth ridges at their original height and shape. In the middle and later shoots of bamboo shoots, as the temperature rises, the growth of the underground stem of the asparagus accelerates, and new stems have been taken out of the ridge surface to extract the ground. Therefore, it should be checked every day along the bamboo ridge, and any cracks in the roof tile should be harvested in time. Practice has proved that harvesting new long shoots in the afternoon is the best way.
4. The harvest duration of different shoot ages is the number of years indicating the growth of asparagus after colonization. Asparagus harvesting duration is the number of days that asparagus harvests the tender stems each year. Judging the duration of harvesting can be determined by observing the diameter of shoots, the amount of bamboo shoots, and the changes in fiber. As the shoots are continuously harvested, the asparagus plants gradually consume nutrients stored in them, the tender stems become finer, the yield decreases, the degree of fibrosis increases, and the number of deformed bamboo shoots increases. At this time, shoot shoots should be stopped. Young asparagus has small clusters, insufficient developed root groups, limited storage of nutrients, and less harvest days than mature asparagus. The first year of harvesting bamboo shoots can be controlled in about 50 days, and the cultivation of the main planting groves should be continued, and the harvesting days should not be too long. Otherwise, it will not only affect the expansion of the tussocks, but also cause some of the asparagus plants to grow nutrients after harvesting bamboo shoots. After depletion, no new stems can cause death. With the expansion of the plant clusters, the increase of fleshy roots and the accumulation of nutrients will increase the duration of harvesting. The duration of harvesting bamboo shoots in different regions is not the same.
Specific methods for the collection of the stems from the genus of mature mothers: Mature shoots are harvested for about 70 days without leaving the stems, and then harvesting is stopped. Each arbor is grown with 2-3 sturdy stalks. Then the extra bamboo shoots are harvested, which means harvesting in two seasons.留母茎期间,采收的芦笋为夏笋,管理好的成龄笋田可留母茎采收至8月20日左右,然后放垄进入秋季营养生长期。
特别注意的是,留母茎采收期间正值高温多雨期,母茎极易发病,此时应加强对母茎的管理,防治病虫害的发生,保证母茎生长健康,制造更多的光合产物质供应地下新笋芽的生长,提高采笋产量。在二次采笋结束,放垄时将母茎全部割除,不再留母茎生长。
5.采笋期间的田间管理芦笋的采收持续期一般长达2个月以上。在这期间,嫩茎的生长需要大量养分和水分,所以采笋期仍需要加强田间管理,方能取得更高的经济效益。
(1) 采笋期施肥采笋田传统的施肥方法为采前施肥和采后施肥,即采笋期不施肥。事实上,芦笋进入盛产期(4月下旬至7月初)后,对养分的需求量增大,对未施足底的笋田这次施肥尤为重要。每生产100千克芦笋需要氮,磷,钾的比例为10:7:9。不同产量的笋田具体施肥方法是:采笋前结合培垄施总肥量的30%左右为宜,以腐熟的农家肥为主,适当混施少量复合肥,一般每亩施有机肥5000千克左右。每年追施一次,再按需肥量补充复合肥及尿素。采笋结束后施全年总量的70%左右,采笋期应追施复合肥不要施速效氮肥,以免影响芦笋质量。
(2) 采笋田适当浇水芦笋虽较耐旱但对水分要求十分敏感,要抓好几个浇水环节。土壤为壤土的笋田,采笋期间,土壤含水量保持在16%左右有利于提高嫩茎的产量和质量,以后随着气温升高,土壤水分蒸发量增大,可适当增加土壤湿度,一般隔10-15天左右浇1次水(隔行轮浇,浇小水)。尤其是高产品种更应及时浇水,否则容易散头。采笋结束后结合施肥灌大水1次。秋季生长季节一般出现秋旱时要浇水1-2次,在封冻前12月份浇封冻水,以防冬旱,这样第二年采笋前就不必再浇水。
第二节采收后的田间管理采笋工作结束后,为了使嫩茎形成植株并生长茂盛,以促进来年新嫩茎的生长发育,必须做好施肥,浇水等工作。
1.施肥与撤垄采笋结束后必须施足肥料,补充养分供值株生长发育需要。施肥应以腐熟的有机肥为主,施肥量应占全年施肥量的70%。施肥方法是:在采笋即将结束之前,将土杂肥撒入芦笋沟内,结合撤垄将肥埋入土中。每亩施土杂肥4000-5000千克,同时施入氮,磷,钾复合肥60千克,尿素20千克,氯化钾10千克,每亩产量1000千克以上成龄笋在8月中旬时应再追一次秋发肥,每亩追施氮,磷,钾复合肥50千克,尿素20千克,硼肥1.5-2.0千克,重施钾肥,硼肥可增加芦笋的营养品质和增强抗茎枯病的能力。
2.浇水根据芦笋生长的需要,在土壤含水量低于16%时,一般要浇3次关键水。
(1) 采笋结束后,浇放垄水,不浇蒙头水,放垄前首先施足底肥,待芦笋嫩茎抽出地面之后再行浇水,因为此时采过的笋伤口尚未愈合,过早浇水,容易灌伤根茎引起植株死亡。此次浇水,有利于迅速发挥肥效,促进值株的健壮成长
(2) 浇秋季旺发水,为促进秋芽的萌发,8月初追施秋发肥应及时浇水。 因为此时秋茎旺长期,如遇干旱不仅影响秋茎的抽发,而且会导致植株的早衰,因此遇旱及时浇水,是夺取第二年嫩茎丰产的重要措施。
(3) 浇冻前水,不浇冻后水,立冬前后,在土壤未东结前浇最后一次,这对防止冬旱,保持土壤湿润,保护笋芽安全越冬都十分有利,同时也有利于第二年春季幼芽的摧残发与生长,减少芦笋的空心。
第三节劣质笋的产生与预防在采收的白芦笋中,凡变色,空心,开裂,畸形,锈斑和弯曲以及老化味苦者,都称为劣质笋。劣质笋的产生常品种,笋龄,温度,土壤以及水肥管理不当等因素有关。要防止劣质笋的产生,需要了解其发生的原因,采取相应措施进行综合预防。
1.变色笋白芦笋要求嫩茎全白,但在生产中常出现部分笋尖变紫现象。 The color change of the tender stem is mainly related to temperature and light.嫩茎经阳光照射后,产生一种紫色花青素引起变色。有的品种嫩茎在土垄中未长出地面,但遇高温,干旱也会变色。要防止变色,除了选择良种外,还要注意在培垄时要将垄土拍细,拍实,避免土壤有缝隙漏光。采笋时避免笋尖露出地面,遇干旱,高温时则要适时浇水降低土温,保持土壤湿润。
2.空心笋
(1) 类型空心笋即芦笋嫩茎中间空心,由嫩茎中部薄壁组织(髓部)的细胞间隙崩裂,拉开所形成。空心笋多发生在较应用于大的嫩茎上,按嫩茎空心大小和外部形态可分为3种类型:
A、小空心:形态无异常,只是髓部产生断面为圆形的空心,孔径较小,一般都在0.2厘米以下。
B、中空心:嫩茎形状稍扁,外侧中部有纵沟通纹但不明显,空心断面为扁圆型,孔径在0.2-0.5厘米之间。
C、大空心:嫩茎粗大,中上部膨大,呈畸形,嫩茎中部形成明显的纵沟纹,严重时沟纹处开裂,空心断面为长椭圆形,孔径多在0.5厘米之间。
(2) 芦笋嫩茎空心形成的原因
A、低温:低温是造成芦笋空心的主要原因。在采笋前期地温较低,但白天地表温度高于地下温度,造成根系对养分和水分的吸收缓慢,而处于地表部分的嫩茎细胞分生较快,养分和水分不能满足其生长发育需要时,使芦笋产生空心。我国北方气温较低,空心率偏高。
B、施氮肥多:在采笋期间,氮肥使用过多,使芦笋嫩茎细胞组织膨胀过早,过快,中心组织跟不上周边组织的增长而造成空心。
C、笋龄大:笋龄越大,空心率越高。幼龄笋嫩茎较细,细胸结构紧密,出土时间较早,受低温影响小,空心笋相对减少;成龄笋出土晚,受低温的影响较大,空心率相对增多。
D、土壤含水量:调查表明,温度高时,空心率与土壤表层含水量较低有关。
因此,在温度较高时,如果土壤水分过少,将使空心嫩茎明显增多。此时及时浇水会明显地减少空心笋的发生,提高品质。
E、品种差异:根据品种对比调查,格兰蒂、阿波罗、阿特拉斯、弗兰克林等改良系,改良帝王等是空心率较低的品种。
由此可见,芦笋嫩茎空心形成的原因比较复杂,其中品种,温度和湿度是主要原因。为减少嫩茎空心,首先要选用产量高,品质好,不易空心的良种。采笋前期可采用盖膜增温的方法采笋;另外,应尽量保持土壤的温度和重施有机肥;在采笋期间尽量不追施过多的氮肥等。
3.开裂笋嫩茎纵向开裂的叫开裂笋,由嫩茎在生长过程中土壤水分供应不均或在采笋期久旱缺水时骤然降雨或浇水引起;另外,土壤中缺少磷,钾肥或追施氮肥过多也易产生嫩茎开裂。防止方法是,采笋期要少施氮肥,注意氮,磷,钾肥的合理配合施用;浇水要适当,不使土壤过干或过湿,保持土壤水分对嫩茎生长的正常供给。
4.弯曲笋造成嫩茎弯曲的主要原因是芦笋嫩茎在生长中受到硬土块,石块的挤压或划伤,不能垂直生长而向一边弯曲。如果笋垄培土紧密程度不一致或在采笋后封穴培土不实,致使笋垄软硬,坚实不一致,也会造成嫩茎遇硬而向松的一面弯曲生长。 Due to insect bites or mechanical damage, tender stems may cause nutrient transport to be hindered, as well as bending tender stems. In order to prevent the occurrence of bent bamboo shoots, the ridges should be culled from the stones, the hard soil blocks should be crushed, and the ridges should be carefully cultivated. After the bamboo shoots are collected, the backfill soil should be in line with the surrounding soil to prevent and control the underground pests in time. Avoid damage to surrounding tender stems, etc.
5.锈斑笋采出的嫩茎白色表面有一层橙色锈斑为锈斑笋,主要受镰刀菌感染所致。 According to the survey, when bamboo shoots are harvested, it is too high, and shoot rot is also easy to produce rust.防止嫩茎锈斑的方法,除清园除茬要彻底不留残茬外,还要注意采笋前不要离芦笋太近,追施腐熟的有机肥。采笋时留茬高以2-3厘米较合适。另外,采笋期内控制浇水,降低土壤湿度,均有利于防止嫩茎锈斑的发生。 6-7月份用药(双吉胜+代森锰锌)400倍液灌根可有效防治锈斑病。
6.鳞片松散笋及苦味笋芦笋嫩茎顶端鳞片松散现象与芦笋品种有一定关系,另外高温,土壤干燥缺水及养分不足等均易使笋头鳞片松散。
芦笋由于含有一种芸香物质,所以略带苦味,也是其应有的风味。但苦味过重不受消费者欢迎。一般说来,凡是老龄株和幼龄株,在高温,干旱,氮肥过多,磷,钾肥缺少,土壤黏重,土壤偏酸的情况下嫩笋苦味过重。防止苦味的办法是,选用良种,选择适宜的土壤,进行合理的水肥管理,氮,磷,钾科学配方使用,培育健壮的植任,提高嫩茎中的糖分含量。采用以上措施可使芦笋苦味相对减轻。
第七章芦笋的病虫害综合防治随着我国芦笋种植面积的逐年扩大,病虫危害日益严重。危害芦笋的病害主要有茎枯病、褐斑病、根腐病、立枯病、锈病、枯梢病及病毒病等等;虫害有蝼蛄、夜盗虫、蛴螬、地老虎、金针虫、蚜虫、蓟马、十四点负泥虫、红蜘蛛等等。病虫危害轻工者缺株减产,重者近乎绝产。因此,在加强芦笋水肥管理的基础上,一定要高度重视病虫害防治。
第一节芦笋病害及防治
1,茎枯病又称茎腐病或基枯病。是一种分布广,危害重的毁灭性病害。在我国各地均有发生。
(1)症状:该病主要在茎枝上发生。发病初期呈现水渍状,病斑呈梭形或短线形,周围呈现水肿状。随后病斑逐渐扩大,呈现统筹锤形,中心部凹陷,呈赤褐色,斑中最后变成灰白色,其上着生许多小黑点,即病菌的分生孢子器。待病斑绕茎1周时,被侵染茎便干枯死亡。病茎感病部位易折断。
(2)病原菌:芦笋茎枯病的致病病原菌为天门冬茎点霉菌。
(3)发病规律:在气温较高,湿度较大梅雨天气,最易发生和蔓延,因此降雨的次数及多少,与茎枯病的轻重有直接关系。
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