Where is the latest production area of Tongcao (rice-paper plant pith)? A detailed explanation of its distribution
Tongcao, also known as Koutuo, Linan, Huoduo, Yishang, Huacao, etc., is the stem pith of Tetrapanax papyrifer, a green shrub or small tree of the Araliaceae family. It has the effects of clearing heat and promoting diuresis, and promoting qi and lactation. It mainly treats damp-warm disease with red urine, strangury with painful urination, edema with scant urine, failure of milk secretion, and other conditions. Now let us take a look together at where Tongcao is produced!
Where is Tongcao produced?
Tongcao production areas are distributed in the southwest as well as Shaanxi, Jiangsu, Anhui, Zhejiang, Jiangxi, Fujian, Taiwan, China, Hubei, Hunan, Guangdong, Guangxi, and other places. At present, the Chinese market mostly uses Chuanmutong, Baimutong (Baitongcao), and Tetrapanax papyrifer as substitutes, while Japan uses Akebia quinata and Akebia trifoliata. The Taiwan, China market mostly uses Chuanmutong and Akebia longiracemosa (Taiwan Mutong). The mainland once used Guanmutong as a substitute, but it was banned because it is toxic.
The production environment of Tongcao
Tongcao grows in sunny, fertile, thick soil at an altitude of several 10 to 2800 meters, or is cultivated in gardens. It likes light and warmth, and grows well in moist, fertile soil. Its roots have strong horizontal growth ability and can form a large number of root suckers. It is not very cold-tolerant, and the overwintering temperature should be above 5°C. It is suitable for cultivation in fertile sandy loam. It has strong vitality and can also spread on its own, but it sheds its leaves in winter. It is suitable for planting on both sides of roads and at the edges of gardens under large trees, where it can suppress weed growth and reduce soil erosion.
Cultivation techniques for Tongcao
1. Site selection and land preparation: The cultivation site for Tongcao should be selected in mixed wood forests with convenient irrigation and good drainage, in mountainous valley areas of secondary forests, and on gentle slopes with a gradient not exceeding 10 to 15 degrees, in fertile brown forest soil or sandy soil. Land preparation should be carried out before sowing.
2. Propagation techniques: Tongcao is propagated by seeds. The suitable planting time is from April to October. On rainy days or on sunny afternoons when the sun is slanting, open furrows at a row spacing of 20 to 25 cm and sow in drills. The plant spacing can be determined according to soil fertility, intensity of management, and difficulty of drainage and irrigation. After the seeds are sown in the furrows, cover with 2 to 3 cm of soil and press down.
3. Field management: After sowing Tongcao, keep the soil moist. During the seedling growth period, attention should be paid to drainage. When the seedlings are more than 30 cm tall, trellises should be set up to support the vines. When artificial trellises are used, various branches can be built into fence supports, and small trees or shrubs such as Vitex trifolia and Tephrosia candida can be used. Apply farmyard manure 2 to 3 times each year during the growing period.
4. Pest and disease control: Tongcao has few diseases during the growing period, mainly insect pests. The larvae of the Akebia swallowtail butterfly bite leaves and stems from July to September. During the occurrence period, spray with 90% trichlorfon at 500 to 800 times dilution. Aphids damage the leaves; spray with 40% dimethoate emulsifiable concentrate at 2000 times dilution.
5. Harvesting and seed retention: In autumn and winter, cut the base of Tongcao, remove the head, tail, and young branches, scrape off the coarse outer bark of the woody stem, and dry in the sun. During drying, straighten the vine stems. When they are about 70% to 80% dry, sort them by diameter and bundle them, then continue drying until done. For seed retention, select seeds that are large, plump, and free of pests and diseases.