How to Grow Bupleurum for Higher Yields? A Detailed Guide to Practical Cultivation Techniques
Bupleurum is a perennial herb of the Apiaceae family, whose roots are used as medicine; it is a traditional Chinese medicinal species in great market demand. As social demand increases year by year and wild resources become increasingly scarce, the market gap grows ever larger, and the market prospects for cultivated Bupleurum are very broad. Cultivated Bupleurum is mainly grown by direct sowing in spring. Its cultivation method is described below.
1. Site selection and land preparation
Bupleurum prefers warm, moist environments; it is cold-tolerant and drought-tolerant, but afraid of waterlogging. For production, it is best to choose fertile, loose, well-drained open fields or gentle-slope mountain land for planting. Plots that are heavy clay, prone to standing (stagnant) water, or have thin soil should not be planted. After the site is chosen, apply 2500 kg of farmyard manure, 50 kg of superphosphate, and 20 kg of potassium sulfate per mu as base fertilizer, plow 30 cm deep, level and harrow fine, and make flat beds 110 cm wide. In areas with abundant rainfall, raised beds 130 cm wide can be made, with drainage ditches dug around the beds.
2. Germination promotion
Bupleurum seeds have strict temperature requirements for germination; the optimal germination temperature is 18°C-22°C, and germination is difficult above 25°C. Bupleurum takes a long time to germinate; at 20°C, it takes 20 days to reach 50% germination. Therefore, whether the planting time is arranged properly directly determines the success or failure of cultivation. China is a vast country, and the temperature difference between north and south in spring is great; growers can arrange planting according to the local soil temperature. For example, if in a certain area the soil temperature reaches 18°C-22°C around April 20, then germination can be started around April 1.
Before germination promotion, first soak the seeds in warm water at 40°C-50°C for 4-6 hours, remove the shriveled seeds floating on the surface, mix the plump seeds that sink to the bottom with clean river sand at a volume ratio of 1:2, and place them in an open pottery container or a soil pit to promote germination, keeping the temperature at 18°C-22°C. After about 20 days, when 1/3 of the seeds have “broken white” (shown the radicle), they can be sown. The seeding rate is 2-3 kg per mu.
3. Sowing
On the prepared bed surface, open four shallow furrows 10-15 cm wide and 1·5 cm deep along the direction of the bed ridge, water them thoroughly, evenly scatter the germinated seeds on the bottom of the furrows, cover with fine soil 0·2-0·3 cm thick, and cover with grass to keep warm and moist. After 3-5 days, seedlings emerge one after another. When 60% of the seedlings have emerged, remove the covering grass; if the bed surface is too dry, sprinkle water to build up soil moisture, or water, to wait for full emergence.
4. Field management
After full emergence, pay attention to preventing drought and protecting the seedlings. Pull weeds and clear the weeds. When the seedlings are 5 cm tall, thin them to a plant spacing of 5 cm. After thinning, hoe shallowly to “harden the seedlings”. When the leaves become thicker and the leaf color dark green, broadcast 10 kg of urea per mu and water thoroughly once. After that, control watering and frequently hoe shallowly to clear weeds. Before the rainy season arrives, broadcast 20 kg of diammonium phosphate per mu and water. During the rainy season, strictly prevent standing water and waterlogging in the field. Standing water and waterlogging in the field can easily cause root rot and lead to large yield reductions. Before the ground freezes, water once for overwintering and broadcast 3000 kg of finely crushed farmyard manure per mu.
In the early spring of the second year, rake away the dry stems and leaves on the ground and water to promote greening. When the seedlings are 12-15 cm tall, open furrows and apply 25 kg of diammonium phosphate and 8 kg of potassium sulfate per mu, then water thoroughly once. After that, control watering and strictly prevent standing (stagnant) water. In May, Bupleurum begins to bolt and flower one after another. Except for seed-production fields, these should be cut off in time to avoid unnecessary consumption.
5. Pest and disease control
Bupleurum is affected by root rot, which occurs due to high temperature and humidity and standing (stagnant) water in the field. Diseased plants fade from green to yellow, then dry up and die; when pulled out, the roots can be seen to be rotten. In addition to applying more phosphorus and potassium fertilizer, the control method is to do a good job of drainage in the rainy season and not allow water to stand in the field; in the early stage of the disease, irrigate the plants with 50% carbendazim 1000-fold solution or 70% thiophanate-methyl 1000-fold solution. Among insect pests of Bupleurum, aphids are most common during the seedling stage in spring and can be killed with “Pushi Ya” and similar products.
6. Harvest and processing
In late October of the second year after sowing, harvest the aboveground stems and leaves, remove the old stems, sun-dry them, and tie them into bundles; this is soft Bupleurum (seedling Bupleurum). Along one end of the bed, carefully dig out the root strips, shake off the soil, remove any remaining stems and leaves, and sun-dry them to obtain the commercial product. Dried Bupleurum is best when it is dry, has long roots, and is free of impurities. Generally, the yield per mu is 150 kg of Bupleurum roots and 250 kg of Bupleurum seedlings (aboveground stems, leaves, and stalks at 3-4 yuan per kg).
In growing Bupleurum, rational close planting, heavy application of phosphorus and potassium fertilizer, removal of flower bolts, and prevention of root rot are the main measures for increasing yield.