How to cultivate Platycodon grandiflorus for high yield? Detailed explanation of the key technical points
Platycodon grandiflorus, also known as "soil ginseng" or bellflower. It is a perennial herbaceous plant of the Campanulaceae family, genus Platycodon. Platycodon grandiflorus is a medicinal and edible variety, with its underground rhizome used medicinally; it has the effects of diffusing the lung, soothing the throat and resolving phlegm, and discharging pus. It mainly treats cough with copious phlegm, sore and swollen throat, hoarseness, lung abscess, coughing up pus and blood, and other conditions. Health foods processed from Platycodon grandiflorus, such as Platycodon dishes, shredded Platycodon, and candied Platycodon fruit, are not only delicious but also have medicinal and health benefits, and are deeply loved by urban and rural people. Platycodon grandiflorus is also an export product that earns foreign exchange, mainly exported to South Korea, Japan, the United States and other countries around the world. It has relatively high edible, medicinal and economic value. Therefore, appropriately developing Platycodon grandiflorus production can promote local agricultural structural adjustment and is also an effective way for farmers to become wealthy.
I. Market prospects
The annual medicinal demand was 4.5 million kg in the late 1970s and early 1980s. Calculated at a 10% annual growth rate, it should be above 10 million kg today. Platycodon dishes are a famous dish of the Korean ethnic group in China. As an edible demand, it is mainly in the Yanbian and surrounding areas where the Korean ethnic group lives in Northeast China, and has now spread to hotels, restaurants and all parts of the country in major cities such as Beijing, Tianjin, Guangzhou and Wuhan. Abroad, it was originally mainly South Korea, and has now spread to Japan, the United States and Southeast Asian countries. In 2002---2003, the “World Cup” was held in South Korea, and the South Korean business community lost no time in widely promoting its traditional famous dish “Platycodon dishes”, with very good results. The Platycodon market has already shown a trend of spreading throughout the world. And the raw material for South Korean Platycodon dishes mainly comes from China. South Korea imports ten thousand tons of fresh Platycodon from China every year. Therefore, with the expansion of the Platycodon market, its market will have broad prospects.
II. Market conditions
In 2003, due to insufficient production relative to demand, the price of dried Platycodon reached as high as 15--18 yuan per kg, and export grade was above 20 yuan. Fresh Platycodon was above 6 yuan. The output value per mu was 5000---10000 yuan. After going through the troughs of 2005, 2006, 2007 and 2008, Platycodon rose all the way in the second half of 2009; the current market price is as high as 46-50 yuan, and Platycodon inventory is weak, with almost no planted area in the fields to speak of. Industry insiders generally believe that Platycodon will hover at high prices for 2-3 years, and planting Platycodon this year can be regarded as the best opportunity.
III. Cultivation points
1. Growth habits: Platycodon grandiflorus prefers a warm and humid climate. It is cold-resistant, able to endure low temperatures of -40°C, and can also endure high temperatures of 40 degrees. It is drought-tolerant and afraid of waterlogging. It is suitable for growing in an environment with sufficient sunlight and abundant rainfall. As for soil requirements, deep soil layers and sandy loam or loam rich in organic matter are preferable. Seeds germinate in 15 days under conditions of 10~15°C; seeds stored until the next year have a lower germination rate and are not suitable for seed use. The suitable growth temperature is 18~33°C. Two-year-old plants are prone to lodging in wind and rain.
2. Land preparation and fertilization: Choose a field with high terrain, good drainage, deep soil layers, loose and fertile soil, and sandy loam rich in organic matter, and carry out deep ploughing and careful cultivation, with a ploughing depth of more than 30cm. In combination with land preparation, apply sufficient base fertilizer: apply 5000 kg of farmyard manure per mu (or 100 kg of cake fertilizer), 25 kg of urea, 30 kg of diamine, and 20 kg of potassium sulfate. Level the plot and harrow it finely, clear the drainage ditches around it, and wait for sowing.
3. Sowing: Platycodon grandiflorus is propagated by seed. Sowing periods include spring sowing, summer sowing, autumn sowing and winter sowing, but winter sowing and spring sowing produce good and uniform seedlings. When sowing, mix Platycodon seeds with yellow sand at a ratio of 1:10, then evenly scatter them on the prepared seedbed surface, and use a rake reversed to level it twice, so that the soil covers the seeds. The sowing rate per mu is 2--3 kg.
4. Field management
(1) Mulching. Platycodon emerges relatively slowly, so production should adopt mulching protection measures to facilitate emergence. There are two mulching methods: first, plastic film mulching. The method is, after the ground thaws, when the soil surface is somewhat dry but not quite dry, use 2 m wide plastic film to cover the sown Platycodon field. Press the surroundings firmly with soil to prevent damage by wind. Second, crop straw mulching. This means using wheat straw, rice straw and other crop straw to cover the surface of the Platycodon field with a layer. The purpose of mulching is to maintain soil temperature and humidity to facilitate emergence. After the Platycodon seedlings emerge uniformly, the mulch can be removed immediately to avoid affecting the growth of Platycodon seedlings.
(2) Weeding. It can be divided into chemical weeding and manual weeding. For chemical weeding, around the Spring Equinox, use 50% acetochlor emulsifiable concentrate before weed emergence after the sowing or transplanting field is bedded and 7~10 days before transplanting. Use 80ML of herbicide per mu, dilute with 30 kg of water, and evenly spray it on the surface of the Platycodon field for pre-emergence field weeding, with a weeding rate of more than 80%. Note that it should not rain within two days after spraying, so as to avoid the agent seeping into the ground and affecting the germinating Platycodon seeds. Weeds resistant to the herbicide should be pulled out manually in time, so as not to affect Platycodon growth. Chemical weeding and manual weeding should complement each other and bring out the best in each other.
(3) Topdressing. During the whole production process, Platycodon should be topdressed three times: the first topdressing when Platycodon seedlings have two pairs of true leaves, applying 5 kg of urea per mu; the second topdressing around the Beginning of Autumn, applying 5 kg of urea and 5 kg of potassium dihydrogen phosphate per mu; the third topdressing in winter after one year of Platycodon growth, spreading 3000 kg of farmyard manure, 10 kg of urea, and 10 kg of potassium dihydrogen phosphate per mu on the surface of the Platycodon field. Fertilization should be carried out in combination with rainfall or irrigation.
(4) Drainage and irrigation. Platycodon is afraid of waterlogging, so drainage should be carried out immediately in rainy weather. In dry weather, it should also be watered in time.
(5) Chemical regulation. Platycodon stems are relatively soft and prone to lodging in wind and rain. Properly controlling stem height can prevent lodging and facilitate normal growth of Platycodon. The method is, when two-year-old Platycodon plants are 15CM tall, spray once with mepiquat chloride, and three consecutive sprays are sufficient.
(6) Removing flower buds. Spraying 1000PPM ethephon 1--2 times at full flowering stage can effectively remove flower buds and increase yield by 45%. (PPM is a concentration unit: parts per million)
5. Pest and disease control: The main pests of Platycodon include cutworms, wireworms and other underground pests that bite and eat seedlings, causing missing seedlings and broken rows. For control, in combination with land preparation, use 200 grams of phoxim per mu to make poisoned bait and place it underground to kill them. Around Grain Rain, use 50 grams of phoxim and 30 grams of fenvalerate per mu, with a total of 30 kg of water, and spray the soil surface from 4--6 pm to kill them. Red spiders and aphids are killed by spraying 1500-fold liquid of 40% dimethoate emulsifiable concentrate. The main disease of Platycodon is root rot, which damages the roots and causes the whole plant to die. During land preparation, 5 kg of carbendazim per mu can be used to disinfect the soil. Pull out diseased plants in time and treat the diseased holes with lime. For Fusarium wilt, in the early stage of the disease, the part near the ground turns brown and becomes dry-rotted; when humidity is relatively high, a powdery white mold layer appears on the surface of the rhizome, and finally the whole plant dies. In the early stage of the disease, spray 800-fold liquid of 50% carbendazim for control. Once every 7 days. Spray three times consecutively. For ring spot disease, the affected leaves have nearly circular virus spots, brown, with concentric rings, and black dots on them. In the early stage of the disease, spray 1000-fold liquid of 50% carbendazim for control. Once every 7 days, spray three times consecutively.
6. Harvesting and processing: The production cycle of Platycodon is two years. Generally, harvesting is carried out in autumn after the aboveground stems and leaves wither in the second year of growth. First cut off the aboveground stems and leaves, then dig out the underground rhizome, and remove all soil. Then select straight roots, without branches, without scars, with a thickness of more than 1cm and a length of more than 18cm that meet export-grade requirements for export. Then scrape off the outer skin of the remaining Platycodon and dry it in the sun for medicinal use. Generally, the fresh yield per mu is more than 2000 kg. Converted to dried commercial product, it is 300-350 kg.
IV. Benefit analysis. 1. Investment: chemical fertilizer 180 + pesticide 10 + seeds 180 + mechanical ploughing 50 + labor 300 = 720 yuan. 2. Income: 2000 kg (yield) × 5 yuan (fresh product price) = 10000 yuan. 3. Profit: 10000-720=9280 yuan