Cultivation techniques of Platycodon grandiflorum

First, form

Platycodon grandiflorum is a perennial herb, 30-100cm tall, the whole plant is smooth and glabrous, the root is fleshy, the outer skin is yellow-brown or grayish brown, the stem is erect, leaf blade ovate to lanceolate, long 2~7cm, broad 0.5~3cm, apex acuminate, margin sharply serrate, base cuneate. The flowering period is from July to September and the fruiting period is from August to October.

Second, the growth environment

Platycodon grandiflorum likes cool, moist, light and cold resistance. The suitable temperature range for growth is 10 ℃ ~ 20 ℃, the optimum temperature is 20 ℃, and it can bear the low temperature of minus 20 ℃. The plant grows well in humus soil or sandy loam with deep, loose and fertile soil and good drainage. Afraid of stagnant water, soil stagnant water is easy to cause root rot.

Third, planting technology

1. Platycodon grandiflorum for land preparation is a deep-rooted plant, and humus soil or sandy soil with deep, loose and fertile soil and good drainage should be selected. After selecting the land, 30-40 kg per mu of compound fertilizer is sprinkled into the ground, turning more than 30 cm deep, leveling and raking fine.

2, timely sowing Platycodon grandiflorum is mainly propagated by seeds, spring sowing, autumn sowing or winter sowing, 1.5 kg per mu. Can also raise seedlings and transplant, because the direct seeding yield is higher than transplanting, and the root straight bifurcation is less, easy to scrape processing, good quality, multi-use in production.

The strip sowing method was used to trench the finished border surface according to the row spacing of 21-23 cm, the sowing depth was less than 1 cm, and the soil was covered after sowing. The wide strip sowing method can also be used, that is, the width of the trench is 10 cm, the line spacing does not change, the soil is covered after sowing, and the wide strip sowing method has many advantages, such as simple management, good quality of finished products, and so on. The temperature is suitable and the seedlings can emerge in about 15 days. Fourth, field management

1, reasonable close planting row spacing 21-23 cm, plant spacing 3-5 cm. If the plant is too dense, the growth of the plant is weak and it is vulnerable to diseases and insect pests. Too thin, low yield. If the seedlings are suitable for wide strip sowing, the seedlings are not crowded, and there is no need to remove too many seedlings. Proper close planting is the key to increase production.

2. Platycodon grandiflorum grows slowly in the early stage and is easy to breed weeds, so it should be pulled out in time to prevent the spread of grass famine. The planting site should be watered thoroughly first, and when it is dry and wet, the soil should be loosened once, so as not to dry and crack the ground and cause dead seedlings. Mid-ploughing should be carried out when the soil moisture is moderate. After the plants grow up and close the ridges, there is no need for intermediate ploughing and weeding.

3. Topdressing urea should be applied about 25 kg at seedling stage to promote seedling growth. At the end of June, more fertilizer was applied at flowering stage, mainly phosphorus and potassium fertilizer, to prevent the growth from being affected by excessive nutrient consumption due to flowering and fruiting. After entering winter, it is necessary to re-apply overwintering fertilizer, combined with fertilization to cultivate the soil. In the following year, when the plant height is about 1 meter in spring, the amount of nitrogen fertilizer should be properly controlled, combined with topdressing phosphorus and potassium fertilizer to make the stem grow sturdy, which can prevent or reduce lodging.

4. The flowering period of Platycodon grandiflorum is longer, which consumes a lot of nutrients and affects the 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, such as cutting buds with a sickle. Or with multiple frustrations, sprayed in full bloom, can prevent flowering.

5. The planting density of Platycodon grandiflorum is high. When it is hot and humid in summer, drainage should be done in time to prevent stagnant water and rot roots, resulting in reduced production.

Fifth, major diseases and insect pests

1, root rot

(1) the symptom is a root disease caused by Fusarium oxysporum. During the disease period from June to August, the root was yellowish brown and rotten at the initial stage, and then gradually expanded. When the disease was serious, the aboveground part withered and died.

(2) the prevention and control methods should pay attention to crop rotation and eliminate stagnant water in time. If you plant in low-lying or rainy areas, you should make a high border. When preparing the soil, apply more base fertilizer, improve the soil, enhance the disease resistance of the plant, apply lime powder 50~100kg per mu, can reduce the harm, or disinfect the soil with 5kg carbendazim per mu, and prevent and cure the disease with 1000 times of topiramate. Remove the diseased plant in time.

Sixth, harvest and processing

1, harvest

Planting Platycodon grandiflorum due to different regions and sowing time, the harvest years are also different, generally harvested in the same year, or the following year. The harvest period can be carried out from the end of September to the middle of October in autumn or before the sprouting of Platycodon grandiflorum in the following spring. The autumn collector's weight is solid and the quality is better. Generally, when the aboveground stems and leaves wither, the roots have not been enriched too early, and the drying rate is low, which affects the yield; it is not easy to peel too late. When starting to dig, prevent the main root from being broken.

2, processing

After the fresh roots are dug out, clean the soil and Reed head, scrape off the cork with bamboo knives, wood edges, porcelain pieces, etc., wash, dry or dry. The skin should be scraped while it is fresh. If it takes a long time, the root skin will be hard to shave. It should be dried in time after shaving. Platycodon grandiflorum takes back too much processing, it can be buried with sand to prevent the skin from drying and shrinking, so it can be easily peeled. The drying rate is 30-35%. The yield per mu is 150-200 kg per year and 350-400 kg per mu in 2-3 years.