Key Cultivation Techniques for the Chinese Medicinal Herb Saposhnikovia divaricata

Saposhnikovia divaricata is a Chinese herbal medicine, also known as Tongyun, Huiyun, Huicao, Baizhi, Baizhong, etc. It is a perennial herb with the effects of dispelling wind and releasing the exterior, overcoming dampness and relieving pain, and stopping spasms. So, what are the cultivation techniques for Saposhnikovia divaricata?

1. Site selection and land preparation

Saposhnikovia divaricata is a deep-rooted plant, and its main root can reach 50-60 cm in length. It should be planted in sandy loam soil with high, dry terrain and good drainage; when planted in clay soil, the roots of Saposhnikovia divaricata are extremely short, highly branched, and poor in quality. Saposhnikovia divaricata is a perennial plant, so sufficient base fertilizer should be applied during land preparation, using 3000-4000 kg of barnyard manure and 15-20 kg of superphosphate per mu, then deep plowing and fine harrowing. In the north, make flat beds 1.3-1.7 m wide; in the rainy areas of the south, make high beds 1.3 m wide with ditches 25 cm deep.

2. Sowing

Sowing can be done in spring and autumn. For spring sowing, the Yangtze River basin sows from late March to mid-April, and North China sows from early to mid-April; for autumn sowing, the Yangtze River basin sows from September to October, and North China sows before the soil freezes, with seedlings emerging the following spring. For spring sowing, the seeds need to be soaked in warm water for 1 day so that they fully absorb water and germinate more easily. In the prepared bed, open furrows 30-40 cm apart for drilling, with a furrow depth of 2 cm. Sow the seeds evenly into the furrows, cover with soil and level it, press lightly, cover with grass and water, and keep the soil moist. Seedlings can emerge 20-25 days after sowing. Use 2 kg of seeds per mu.

3. Field management

(1) Thinning: when the seedlings are 5 cm tall, thin them to a plant spacing of 7 cm; when the seedlings are 10-13 cm tall, final thinning should be done to a plant spacing of 13-16 cm.

(2) Weeding: before June, weeding needs to be carried out several times to keep the field clean. When the plants close in the rows, first remove the old leaves, then earth up around the roots to prevent lodging; when winter comes, combined with cleaning the field, earth up again to help the roots overwinter.

(3) Topdressing: topdressing should be applied once in early June or late August each year, using human manure and urine, superphosphate, or compost, applied in furrows between the rows.

(4) Removing bolting stems: for plants over 2 years old, all except those kept for seed production should have their bolting stems removed in time.

(5) Drainage and irrigation: during the period from sowing or transplanting to seedling emergence, the soil should be kept moist. Saposhnikovia divaricata has strong drought resistance and mostly does not need irrigation. During the rainy season, pay attention to timely drainage to prevent water accumulation and root rot.

4. Pest and disease control

Powdery mildew: it damages leaves in summer and autumn. Control methods: (1) apply phosphorus and potassium fertilizers and pay attention to ventilation and light transmission; (2) when the disease occurs, spray with 50% thiophanate-methyl at 800-1000 times dilution for control.

Yellow-winged fennel borer: it occurs at the bud and flowering stages and damages flower buds and fruits. Control methods: in the morning or evening, spray with 90% trichlorfon at 800 times dilution or BT emulsion at 300 times dilution for control.

Yellow swallowtail butterfly: damage begins in May, and the larvae bite and feed on leaves and flower buds. Control methods: (1) manual capture and killing; (2) during the young larval stage, spray with 90% trichlorfon at 800 times dilution or 80% dichlorvos emulsifiable concentrate at 1000 times dilution.

At harvest, note that the roots of Saposhnikovia divaricata go relatively deep and the roots are brittle and easily broken, so when harvesting, open a deep furrow from one end of the ditch and dig them out in sequence. Remove the remaining stems, leaves, and soil, remove the fibrous hairs when half-dried in the sun, grade according to root thickness and length, tie into small bundles of 0.25 kg, and sun-dry until completely dry.