Scientific Cultivation Techniques of Platycodon grandiflorum

Platycodon grandiflorum is widely planted in the river valley area along the river in Shangri-La County, especially with the rise of prices in the past two years, the planting area has increased year by year. Now I will introduce in detail the planting techniques of Platycodon grandiflorum, which has been used as a reference for the majority of farmers.

1. Land selection and preparation: after selecting sandy loam land with sufficient sunshine, deep soil layer and good drainage, apply soil circle fertilizer 3000kg per mu, add calcium superphosphate 20kg or diammonium phosphate 15kg, spread evenly in the land, deeply plough 25-30cm, level Harrow fine, make 1.2m-1.5m wide, 15cm high border, long and short depending on the topography.

2. Select improved varieties: Platycodon grandiflorum seeds should choose seeds that are not aged for more than 2 years (if the seeds accumulate for one year, the germination rate should be reduced by more than 70%). The amount of seed used per mu is 1.5ml and 2kg.

3. Soak the seeds of Platycodon grandiflorum in about 40 ℃ warm water, stir them constantly, let the seeds be heated evenly, and then rinse with clean water to remove impurities when the temperature drops to about 20 ℃. Soaking the seeds for another 12 hours, or soaking the seeds with 0.3% potassium permanganate solution for 12 hours, then mixing well with appropriate amount of wet sand, stacking for a few days and then planting can significantly improve the germination rate.

4. Sowing at the right time (1) the direct seeding seeds in the field have less plant forks, straight roots and high quality, and the method is simple, time-saving and labor-saving. It is widely used, and live broadcasts are mostly held in spring. For direct seeding in the field, strip sowing is often used, and horizontal trenching is made on the bed surface, with a depth of 2mur3cm and a distance of 20mur25cm. The treated seeds are mixed with 10 times fine sand and sprinkled evenly into the ditch. After covering the soil, gently pressing, watering after sowing, keeping the soil moist before emergence, covering straw or pine needles, moisturizing and keeping warm, seedlings emerge in May of the following year. (2) the method of seedling transplanting can select improved varieties and strong seedlings, and adjust the planting width, which is beneficial to increase the yield per unit area. The seeds with large, full and pest-free seeds should be selected to raise seedlings, and the seed treatment of seedling is the same as that of direct seeding in the field. The bed for raising seedlings is 1.2 to 1.5 meters wide and 25 centimeters high. Before making the bed, base fertilizer is applied and evenly mixed with the bed soil, leveling and raking fine, ditching on the whole bed surface according to the row spacing of 10 cm, the ditch depth of 1.0 cm 1.5 cm, sowing seeds, covering soil thickness of 1 cm slightly compacted, covered with grass or leaves, watering to keep the soil moist, generally about 15 days after the seedlings are unearthed, remove the mulch. After the aboveground part withered in late autumn or before seedling emergence in the following spring, the roots were dug up, according to the row spacing of 20 cm 25 cm, the ditch depth of 10 cm 15 cm, open a horizontal ditch on the transplanting bed, put the plant obliquely in the ditch, plant spacing 6 cm, cover fine soil after planting, and water it with a little compaction.

5. Field management: when the seedling height is about 5-7cm, time seedlings, fixed seedlings, excessively dense seedlings and weak seedlings should be fixed, and seedlings should be fixed according to seedling spacing of 6-10cm; combined with intertillage, weeding and topdressing fertilizer should be weeded in time because the early growth of Platycodon grandiflorum is slow. It is generally carried out three times, the first time when the seedling height is 7mur10cm, the second time in January, and the third time in a month, in order to weed as soon as you see the grass. Thin human feces should be applied 1-2 times at seedling stage to promote the growth of seedlings. The application of fertilizer at flowering stage is mainly phosphorus and potassium fertilizer in the middle stage to prevent the growth from being affected by excessive nutrient consumption due to flowering and fruiting. After winter, it is necessary to re-apply overwintering fertilizer, combined with fertilization to cultivate the soil; timely drainage Platycodon grandiflorum is afraid of stagnant water, soil water is easy to cause root rot. When it is hot and rainy in summer, ditch drainage should be done in time to prevent stagnant water from rotting roots, resulting in reduced yield; flower and fruit thinning Platycodon grandiflorum has a long flowering period, which consumes a lot of nutrients and affects root growth. In addition to staying in the field, thinning flowers and fruits can improve the yield and quality of roots, and buds can be removed manually in production, such as cutting buds with a sickle or spraying with multiple frustrations in full bloom to prevent flowering. Plant hormone ethephon can also be used. The concentration of 1000ppm is sprayed on the flower buds at full flowering stage. The flower removal effect can be achieved by using 1125-1500 kg liquid per hectare. This method has the advantages of high efficiency, low cost and safe use.

6, pest control: the main diseases and insect pests of Platycodon grandiflorum are ring disease and sheath blight, mainly harmful leaves, which can be sprayed with 1 ∶ 1 ∶ Bordeaux solution or 50% carbendazim 1000 times solution at the initial stage of the disease. Canker is easy to occur when the temperature is humid, the duration of condensation is long and Rain Water is long, the leaves are brown and the stems turn brown from top to bottom. 72% agricultural mycin sulfate wettable powder 4000 times solution can be used for continuous control for 3-4 times. For underground pests such as mole cricket, ground tiger and grub, trichlorfon poison bait can be used.

7. Harvest and processing: seed harvest: from August to October, when the shell of the capsule is yellowish and the top of the fruit is initially cracked, the seeds are full and black after breaking, and they can be picked in batches. The harvested seeds should not be directly exposed to the sun, but can be stacked in an indoor ventilated place for 3 to 4 days. The embryos mature naturally and then dry. After removing the fruit shell, the seeds are stored in a dry and ventilated place with a cloth bag or paper bag device. The seeds should be stored at low temperature for one year. Root harvesting: harvesting in the same year of transplanting or the second year of direct seeding. Harvest from October to November at the end of autumn, first cut off the stems and leaves, dig out the roots, wash the soil with clean water, drain the water, scrape off the cork while fresh, such as bamboo or glass, porcelain, etc., then dry or dry. You can also dig and scrape as you go, to prevent the skin from drying and shrinking, so it's easy to peel.