Detailed Explanation of Key Techniques for High-Yield Cultivation of Coptis chinensis

Coptis chinensis, also known as Chuan Huanglian. It is a perennial herbaceous plant of the Ranunculaceae family. Its underground rhizome is used as medicine, with effects of purging fire and drying dampness, clearing heat and detoxifying. It mainly treats conditions such as excessive heat with restlessness, hematemesis, enteritis, acute conjunctivitis, otitis media, unnamed swellings and sores, and impetigo. The main producing areas are Sichuan, Hubei, Yunnan, Guizhou, Hunan and other provinces and regions.

Morphological Characteristics 1. Coptis chinensis: Perennial herb, 20-50 cm tall, rhizome much branched, clustered or fascicled. Leaves basal, ternately compound; petiole glabrous; leaf blade ovate-triangular, firm papery (old leaves slightly leathery); ternately parted, central lobe ovate-rhombic, base with slender stalk 1-2 cm long, lobes further pinnately parted, deep lobes 4-5 pairs, margins sharply serrate; leaf surface green, glossy, with short hairs along veins on the surface, glabrous beneath. Flowering stems several, 12-25 cm tall; dichasial or polyasial cyme terminal, flowers 3-8, white-green or yellow; sepals 5, yellow-green, narrowly ovate; petals linear, lanceolate; stamens numerous; carpels 8-12, free; aggregate fruit 6-12, each fruit with 8-12 seeds, oblong, brown or dark brown.

2. Coptis deltoidea: Perennial herb, plant slightly taller than Coptis chinensis. Rhizome unbranched or few-branched, with nodes, nodes swollen, internodes relatively slender (commonly known as "guoqiao"), with numerous slender fibrous roots borne on nodes; stolons slender, growing laterally from rhizome nodes, 2-20 per plant, apex with 1 or several compound leaves, with swollen bud scales, able to root and produce leaves upon touching the ground, forming new plants. Leaves clustered, petiole 7-17 cm long, glabrous; ternately pinnate compound leaves, leathery, dark green, glossy. Flowering stem one, 15-20 cm long, terminal paniculate cyme, with 3-9 flowers, pale green; bracts linear-lanceolate, sepals narrowly ovate, petals narrowly linear; stamens about 20, carpels 9-12. Aggregate fruit 6-12, flowers mostly sterile, seeds rarely found in fruit.

3. Coptis teeta: Perennial herb, roots similar to Coptis deltoidea, main differences being: rhizome small and slender, internodes dense, with stolons; leaf blade ovate-triangular, ternately parted, central lobe ovate-rhombic, apex acuminate, pinnately parted, small lobes separated from each other. Petals spatulate to ovate-spatulate, apex obtuse.

I. Growth Habits Coptis chinensis prefers a humid and cool climate, and avoids strong direct sunlight. It requires soil that is "loose on top and firm below" - that is, the upper soil layer should be loose, fertile sandy loam, and the lower soil layer should preferably be clay with strong water and fertilizer retention. It likes water and fertilizer, and fears drought.

II. Land Preparation and Fertilization Select fields on shady slopes or semi-shady slopes of low mountains, and cultivate intensively. In conjunction with land preparation, apply sufficient basal fertilizer: per mu apply 3000-5000 kg of farmyard manure, 20 kg of urea, and 50 kg of phosphate and potassium fertilizer. Then make beds and wait for sowing.

III. Sowing Coptis chinensis is propagated by seed in production. The method of first raising seedlings and then transplanting is mostly adopted. It can also be propagated by division. The sowing period is October to November in autumn. Seedling Raising: Coptis chinensis seeds are of the low-temperature type, and the dormancy period lasts more than 9 months. They need low-temperature treatment to break dormancy and germinate. Once seeds are dried, they lose germination capacity. Therefore, the method is to mix freshly harvested Coptis chinensis seeds with wet sand at a ratio of 1:3, put them in a wooden box, and store in an underground cellar. Alternatively, place freshly harvested Coptis chinensis seeds in a refrigerator and store at 0-6°C for 180 days. Then evenly broadcast the treated Coptis chinensis seeds on the prepared bed surface. Loosen the soil layer so that soil covers the seeds. Water to preserve moisture and promote emergence. Sowing rate per mu is 4 kg. Transplanting: Generally carried out around Qingming, in summer from May to June, and in autumn from September to October. Transplant 2-3 year old Coptis chinensis seedlings at row spacing of 10×10 cm on the prepared bed surface. Water to preserve moisture and promote survival. Division Propagation: Separate branches of 3-4 year old Coptis chinensis from the rhizome, select and retain 1 cm of rhizome with seedlings as division seedlings. Then transplant at row spacing of 15×15 cm on the prepared bed surface. Water to preserve moisture and promote survival.

IV. Field Management Coptis chinensis avoids strong direct sunlight, so after sowing, shade frames should be built over the Coptis chinensis field. After full emergence, attention should be paid to intertillage and weeding. Chemical weeding can also be done with 50% prometryn, 25% diuron, 10% nitrofen, etc. Pay attention to watering in dry weather and timely drainage in rainy weather. Because the growth period of Coptis chinensis is relatively long, topdressing should be applied around the Beginning of Autumn each year with 10 kg of urea and 10 kg of monopotassium phosphate. In winter, spread a layer of farmyard manure on the Coptis chinensis bed surface. Coptis chinensis bolts and flowers from the second year onward; except for plants retained for seed, flower branches should be pruned to prevent nutrient consumption and promote underground rhizome growth.

V. Pest and Disease Control The main diseases of Coptis chinensis include powdery mildew, which can be controlled with Fenningxiu at the early stage of onset. Anthracnose can be controlled by spraying with 800-fold dilution of 50% carbendazim at the early stage of onset, once a week for three consecutive times. Southern blight can be controlled by spraying with 500-fold dilution of 50% Tuzet at the early stage of onset, once a week for three consecutive times. In addition, Orobanche parasitizes the roots of Coptis chinensis, sucking sap and harming its growth. When found, it can be dug out together with roots and soil. Alternatively, before Orobanche seeds mature, remove the Orobanche. The main pest is slugs biting and eating Coptis chinensis leaves; for control, poison bait made from vegetables can be used for trapping and killing.

VI. Harvesting and Processing Coptis chinensis is generally harvested around the Beginning of Winter 5-6 years after planting. The dug-out underground rhizomes of Coptis chinensis should have leaf stalks cut off, mud and sand washed away, and then dried for sale as medicine. Yield per mu is 200-300 kg.