Detailed Explanation of Key Points for Cultivating Cultivated Bupleurum
Bupleurum is a perennial herb of the Apiaceae family, using its roots as medicine, and is a traditional Chinese medicine variety in great market demand. With the year-by-year increase in social demand and the growing scarcity of wild resources, the market gap is widening, and the market prospects for cultivated Bupleurum are very broad. Cultivated Bupleurum is mainly grown by direct seeding in spring. Its planting methods are described below.
I. Land Selection and Preparation
Bupleurum prefers warm, humid environments, is cold-tolerant and drought-tolerant, and fears waterlogging. For production, it is advisable 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 layers are not suitable for planting.
After the land is selected, 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 excessive rainfall, high beds 130 cm wide can be made, with drainage ditches dug around the beds.
II. Germination Promotion
Bupleurum seeds have strict temperature requirements for germination; the optimal germination temperature is 18-22 degrees, and germination is difficult above 25 degrees. Bupleurum takes a long time to germinate; at 20 degrees, it takes 20 days to reach 50% germination. Therefore, whether the planting time is arranged properly directly relates to the success or failure of cultivation. China has a vast territory, and spring temperatures differ greatly between north and south; growers can arrange planting according to the local soil temperature. For example, if in a certain area the time when soil temperature reaches 18-22 degrees is around April 20, then germination can be started around April 1.
Before germination promotion, first soak the seeds in warm water at 40—50 degrees for 4 hours to 6 hours, remove the shriveled seeds floating on the water surface, mix the full seeds that sink to the bottom with clean river sand at a volume ratio of 1:2, and place them in an open ceramic container or earthen pit for germination promotion, with the temperature controlled at 18-22 degrees. After about 20 days, when 1/3 of the seeds have “broken white” (shown white sprouts), they can be sown. The seeding rate is 2 kg to 3 kg per mu.
III. Sowing
On the prepared bed surface, open four shallow furrows 10 cm to 115 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 cm to 0.3 cm thick, and cover with grass to keep warm and moist. After 3 days to 5 days, seedlings emerge successively. When 60% of seedlings have emerged, remove the covering grass; if the bed surface is too dry, sprinkle water to create moisture, or water, to wait for full emergence.
IV. Field Management
After full emergence, pay attention to drought prevention and seedling protection. Pull weeds and eliminate weeds. When seedlings are 5 cm tall, thin them with a plant spacing of 5 cm. After thinning, hoe shallowly to “harden the seedlings”. When the leaves become thicker and the leaf color is dark green, broadcast 10 kg of urea per mu and water thoroughly once. After that, control watering and frequently hoe shallowly to eliminate 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 cause large yield reductions. Before freezing, water once for overwintering and broadcast 3000 kg of finely crushed farmyard manure per mu.
In early spring of the second year, rake away the dry stems and leaves on the ground and water to promote greening. When seedlings are 12 cm to 15 cm tall, apply 25 kg of diammonium phosphate and 8 kg of potassium sulfate per mu in furrows, then water thoroughly once. After that, control watering and strictly prevent standing (stagnant) water. In May, Bupleurum successively bolts and flowers. Except for seed-production fields, promptly cut them off to avoid unnecessary consumption.
V. 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; after pulling them out, the roots can be seen to be rotted. In addition to heavily applying phosphorus and potassium fertilizers, the control method is to do a good job of drainage during the rainy season and not allow standing water in the field. In the early stage of the disease, 50% carbendazim 1000-fold solution or 70% thiophanate-methyl 1000-fold solution can be used to drench the plants. 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.
VI. Harvesting 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 all remaining stems and leaves, and sun-dry them to obtain the commercial product. Dried Bupleurum is best when dry, with long roots and no impurities. Generally, the yield is 150 kg of Bupleurum roots per mu 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 fertilizers, removing flower bolts, and preventing the occurrence of root rot are the main measures for increasing yield.