Latest Cultivation Techniques and Methods Tutorial for Xihuangcao
Xihuangcao (Isodon serra) is a folk herbal medicine, commonly known as Xiongdan Cao, Xuefeng Cao, Huangzhi Cao, Xigou Cao, Xiangchacai, Tuhuanglian, etc. It is mainly produced in the provinces and regions south of the Yangtze River, including Hunan, Sichuan, Yunnan, Jiangxi, Guangdong and Guangxi. Xihuangcao has the effects of clearing heat and draining dampness, reducing jaundice and eliminating dampness, and cooling blood and dissipating blood stasis. It is used to treat acute icteric hepatitis, acute cholecystitis, dysentery, enteritis, traumatic bruises and pain, and other conditions. Xihuangcao is widely used in clinical practice throughout Guangdong, and a variety of health products for preventing and treating hepatitis with it as the main raw material have been developed, such as Xihuangcao granules and Xihuangcao teabags, with very great market potential.
Xihuangcao has strong adaptability to the environment and can grow in areas below 1500 m in altitude. It often grows wild in wet places by streams, village edges, ditch sides, field edges and under forests. Xihuangcao is a long-day plant and likes sunlight. Under sufficient sunlight, the seeds germinate well and the plants grow robustly. Xihuangcao is afraid of waterlogging and afraid of hardened soil. It is suitable for cultivation in loose, fertile, well-drained sandy loam. Low-lying, water-accumulating soil easily causes root rot.
Seedling Raising and Transplanting
Choose a sunny, well-irrigated and well-drained, moist and fertile sandy loam as the seedling-raising site. After removing debris, plow the whole area or half the area, make the soil fine and thorough, and disinfect it. Because Xihuangcao seeds are very small, if the bed soil is relatively compact, fine river sand should be mixed in evenly to improve it during land preparation. The soil clods in the seedbed must be fine, the bed surface soil must be level, and ditches should be opened around it. Generally, the bed width is 1.2 m and the ditch depth is 20-30 cm. Xihuangcao can be propagated and raised by seed propagation, cutting propagation and division propagation.
1. Seed propagation: The sowing time should be chosen in spring when rainfall is sufficient and the temperature rises, or in autumn when the fruits mature. Both broadcasting and drilling can be used. When sowing, the seeds must be mixed evenly with fine mud powder or fine sand at a ratio of 5-6:1 before sowing. After sowing, cover with a layer of fine river sand, and then cover with rice straw on top to keep warm and moist. Water immediately after sowing, spraying evenly and thoroughly with a fine-hole watering can. After emergence, apply diluted fertilizer water 1-2 times. When the seedlings grow to more than 10 cm and have 8-10 leaves, they can be transplanted.
2. Cutting propagation: Generally, softwood cuttings are used. The cuttings can be cut from the seed-production field or the main field. Select robust branches, cut them into 10-15 cm lengths with 3-4 nodes, remove the leaves at the base, keep 1-2 pairs of leaves at the top tip, and cut the lower end obliquely into a horseshoe-shaped cut. The cut cuttings are soaked in rooting powder to ensure a relatively high survival rate. After the seedbed is prepared, open horizontal ditches, place the cuttings obliquely against the ditch wall, with the upper end exposed above the soil surface by 1/4-1/3 of the cutting length, then cover with soil and press firmly. Insert the second row in sequence, with a plant-row spacing of 4 cm × 5 cm. After cutting, water thoroughly, and cover with a 50% shading sunshade net to prevent direct sunlight. Water frequently after cutting to keep moist. Generally, rooting begins after one week, and transplantation can be done after 15 days.
3. Division propagation: For division propagation, the creeping rhizomes (old heads) after harvest in the same year can be densely planted together as a seed-production field, and in winter they need protection from cold and moisture retention. In the following spring, many new tiller seedlings grow from the creeping rhizomes, and these tillers are used as seedlings for transplantation.
4. Transplanting: Apply sufficient base fertilizer to the main field, with 3000-4000 kg of farmyard manure per mu. Rake the bed surface fine and level, and transplant after the land is prepared. When transplanting, cut off the main root of the seedlings, which can cause the seedlings to produce more lateral roots and form a developed root system, benefiting their growth. Transplanting should be carried out on cloudy, windless days or in the evening on sunny days. Generally, plant at a row spacing of 15 cm × 20 cm or 20 cm × 20 cm, by hole planting or furrow planting. After planting, cover with soil and press firmly, and water thoroughly to settle the roots.
Field Management
Throughout the entire growth and development period of Xihuangcao, attention should be paid to uniform fertilizer and water management. Topdressing should follow the principle of “promoting early, controlling midway”. Drain promptly to prevent waterlogging, keep the soil moist, and promptly prevent and control pests and diseases.
1. Topdressing: 10 days after transplanting and settling, the plants begin to grow new roots. At this time, apply N fertilizer once, with 5 kg of urea per mu or a thin application of diluted human and animal manure and urine, to promote early and rapid root growth. 15-20 days after transplanting, apply diluted human and animal manure and urine once more, about 1000 kg per mu. After that, apply organic fertilizer 1-2 times per month. After the plants close the rows, granular compound fertilizer can be applied instead 1-2 times, with 30 kg per mu. After each harvest, loosen the soil and apply fertilizer, which is beneficial for the plants to sprout, branch and survive.
2. Water management: After the seedlings are transplanted, they need to be watered in the morning and evening. In early spring, plastic film mulching is used to keep warm and moist. During the seedling stage, attention should be paid to watering to protect the seedlings, preventing drought and promoting downward root growth, so as to facilitate vigorous seedling growth. After the plants close the rows, water consumption increases, and irrigation should be frequent to keep the soil moist. In the rainy season, especially after heavy rain for several consecutive days, field water should be drained promptly to reduce the occurrence of pests and diseases and prevent root rot.
3. Cultivation and weeding: Generally, cultivate 3-4 times each year to keep the soil loose, keep the field free of weeds, reduce water and fertilizer consumption, keep the field clean, and prevent the breeding and spread of pests and diseases. Cultivation and weeding are generally carried out before the rows close, choosing sunny or cloudy days when soil moisture is not too high. The root system of Xihuangcao is relatively shallow, so cultivation should be shallow. After the rows close, the plants have more branches and luxuriant branch and leaf growth, so the number of cultivation and weeding operations should be reduced to avoid damaging the plants.
4. Pest and disease control: The main pests and diseases of Xihuangcao are powdery mildew and aphids. Powdery mildew is more serious in autumn. If infected plants are found early, they should be pulled up and burned promptly, and pesticide should be sprayed promptly to prevent the disease from spreading. It can be controlled by spraying 70% thiophanate-methyl 800-fold solution, or 25% carbendazim wettable powder 600-fold solution, or 15% triadimefon powder 800-fold solution, spraying once about every 10 days for 2-3 consecutive sprays. Aphids reproduce quickly and spread rapidly, so they must be controlled promptly. Use pesticides with contact, systemic and fumigant triple action for spraying and killing. Pirimicarb, chlorpyrifos, Lannate, aphid killer and other pesticides can be used in rotation for spray control.
Harvesting and Processing
In southern China, Xihuangcao can be harvested 2-3 times each year. After spring planting, the first harvest can be made 90 days later. If managed properly with sufficient fertilizer and water, the second harvest can be made 70-80 days after the first harvest, and the third harvest is made when the plants stop growing before winter. At each harvest, use a sickle to cut the plants at 2-3 cm above the ground at the stem base, which is beneficial for tillering and sprouting. Harvesting is usually carried out on sunny days. After harvesting, dry promptly by sun-drying, shade-drying or oven-drying. After sun-drying, wait until the leaves soften again, then bundle and press them into packages, and they become the commodity.