Planting Techniques and Conditions for Platycodon grandiflorus
A comprehensive introduction to the planting techniques and conditions for Platycodon grandiflorus, as well as knowledge about the best sowing period for this green ornamental plant. Please refer to the detailed introduction below.
Platycodon grandiflorus, also known as balloon flower, belongs to the Campanulaceae family and Platycodon genus. Its roots are used in medicine, known as Platycodon in Chinese herbal medicine. The roots contain platycodon saponin, platycodon saponin 3-0-β-glucoside, polygalacic acid, α-spinasterol, betulin, inulin, polysaccharides, amino acids, etc. It has a slightly warm nature, bitter and pungent taste, and the effects of expectorant, cough relief, and reducing swelling and expelling pus. It is mainly used to treat symptoms such as colds, coughs, bronchitis, unsmooth phlegm, sore throat, chest and abdominal distension. Modern pharmacological experiments show that Platycodon has the effects of expectorant and anti-inflammatory. It has been cultivated in China for a long time, and is produced in most parts of the country, with the largest output in the Northeast and North China, and better quality in the East China region.
(I) Site Selection and Preparation
The seedling and planting sites should be chosen in areas with good sunlight, windward conditions, and convenient irrigation and drainage. The soil should be deep, loose, fertile, and well-drained sandy loam. After selecting the land, apply 3500 kg of decomposed manure, 30 kg of superphosphate, and 150 kg of wood ash per mu, mix well and spread it in the field, then deeply plow and finely rake, level the land and make ridges. The ridge width is 1.2 m, height is 15-20 cm, and the ridge沟 width is 40 cm. When the land is dry, water it first before sowing.
(II) Propagation Methods
Mainly propagated by seeds, divided into direct sowing and seedling transplanting. Direct sowing results in straight and thick main roots with fewer branches, which is convenient for peeling and processing and has better quality, while seedling transplanting results in more branched roots and poorer quality.
1. Direct sowing can be done in autumn, spring, and winter, with autumn sowing being the best. Autumn sowing should be done before mid-October, winter sowing in early November, and spring sowing no later than the end of March. On the prepared ridge, make furrows 2-3 cm deep with a row spacing of 20 cm for broadcasting, with a播种幅 width of about 10 cm. Before sowing, soak the seeds in warm water for 24 hours or in a 0.3% potassium permanganate solution for 12 hours to improve germination rate. During sowing, mix the seeds with wood ash and evenly sprinkle them into the furrows, cover with a thin layer of ash, and finally mulch with straw to keep warm and moist. Use about 0.5 kg of seeds per mu. Seedlings emerge in mid to late April, and after emergence, thin to a spacing of 5-6 cm.
2. Seedling Transplanting
(1) Seedlings are raised in early to mid-March. The method is the same as direct sowing, and the seedlings can be transplanted after one year. Use about 1 kg of seeds per mu.
(2) Transplanting is done after the stems and leaves wither in the autumn or winter of the same year or before the spring sprouting of the following year, with mid-March being the best time for transplanting. Before transplanting, dig up the seedlings, grade them into large, medium, and small, and plant them separately. On the prepared ridge, make horizontal furrows 20 cm apart, about 20 cm deep, with a plant spacing of 5-7 cm. Plant the main roots vertically into the furrows without damaging the roots to avoid branching and affect quality. Make sure the roots are spread out, firmly pressed layer by layer, watered sufficiently to settle the roots, and finally cover the soil slightly higher than the root crown.
Planting Techniques and Conditions for Platycodon grandiflorus
(III) Field Management
1. Cultivation, Weeding, and Topdressing Platycodon requires cultivation and weeding, as well as topdressing three times a year during the growing period. Topdressing is combined with cultivation and weeding. The first cultivation, weeding, and topdressing are done after the seedlings emerge, applying 1500-2000 kg of animal manure per mu to promote healthy seedling growth; the second round is at the end of June, applying 2000 kg of animal manure and 30 kg of superphosphate per mu; the third round is at the end of August, applying 2500 kg of animal manure and 50 kg of superphosphate per mu. In addition, after winter, apply a winter fertilizer of 2500 kg of decomposed manure or shed manure, 100 kg of cake fertilizer, and 50 kg of superphosphate per mu, mixed and applied in furrows near the plants, covered with soil, and earthen embankments made. Before harvest, appropriately control nitrogen fertilizer and apply more potassium and phosphorus fertilizers to make the stems and main roots grow thicker and prevent lodging.
2. Removal of Flower Buds The flowering period of Platycodon is up to three months, and the growth and development of flower buds consume a lot of nutrients. Removing the flower buds can reduce nutrient consumption and allow more assimilates to be stored in the roots, which is an effective measure to increase yield. Manually removing flowers and fruits is labor-intensive and time-consuming. In recent years, using the chemical agent Ethephon to remove flowers has achieved good results. That is, spray 40% Ethephon 1000ppm solution at 75-100 kg per mu during the full bloom period to achieve the goal of removing flowers and increasing yield.
3. Irrigation and Drainage After thinning, if the weather is dry, water appropriately. During the rainy season with high temperature and humidity, clear the ditches and drain the water in time to prevent root rot and reduce yield.
(IV) Diseases and Pests and Their Control
1. Diseases
(1) Fusarium Wilt A disease affecting the entire plant. In the early stage of the disease, the part near the ground and the base of the stem turn brown and become dry and rotten. The pathogen extends upwards along the vascular bundle, causing the whole plant to wilt. When the humidity is high, a white mold layer forms on the surface of the root neck and stem, and eventually the whole plant dies. Control methods: ① Strengthen field management, pay attention to drainage after rain, and promptly remove diseased plants. ② After finding diseased plants in the field, spray the base of the stem with a 50% carbendazim 800-1000 times solution or a 50% thiophanate-methyl 1000 times solution.
(2) Leaf Spot This disease mainly affects the leaves, causing irregular or round brown spots on the leaves, and severe cases can lead to early defoliation. Control methods: ① Clean the garden, promptly remove and burn the diseased residues. ② Start spraying a 1:1:120 Bordeaux mixture or a 65% zinc omadine 500 times solution after the leaves unfold, once every 10 days, for 3-5 times.