Detailed Explanation of Key Scientific Planting Techniques for Saposhnikovia divaricata
[Overview] Aliases: Pangfeng, Guanfangfeng, Dongfangfeng. Saposhnikovia divaricata is the dried root of the perennial herb Saposhnikovia divaricata (Turcz.) Schischk. of the Apiaceae family. It has the effects of inducing sweating and dispelling wind, and removing dampness. It treats wind-cold colds, headaches, joint pain and other conditions. Main growing and cultivation regions of Saposhnikovia divaricata: it is mainly produced in the provinces of Northeast China and in Inner Mongolia, Hebei, Shandong and other provinces. It was originally wild, and the most famous is that produced in Northeast China, called “Guanfangfeng”. In recent years, introduction and cultivation have succeeded in various provinces, and it has gradually shifted to being mainly cultivated.
[Plant Morphology] Saposhnikovia divaricata is a perennial herb with persistent roots. In the first year it only grows basal leaves, clustered, with long and flat petioles whose bases expand into sheaths. The leaf blades are ovate or triangular-ovate. They are bipinnately or nearly tripinnately deeply lobed, with the tips of the leaflets deeply lobed, entire, and hairless. After the leaves wither, the petioles form the brush-like structure unique to Saposhnikovia divaricata. The root is thick and long, cylindrical, with the outer skin pale yellow, light gray or white. The cross-section is white, with a yellow chrysanthemum-heart in the middle. Most biennial Saposhnikovia divaricata plants bolt and flower, with a plant height of 50-80 cm. The stem leaves are alternate and smaller, becoming progressively simpler toward the top, forming incomplete leaves. The inflorescence is much branched, a compound umbel. The petals are white and small. The schizocarp is long-ovate, slightly laterally compressed, with the mericarps having 5 ribs, and the lateral ribs winged. The flowering period is June-July, and the fruiting period is July-August.
[Biological Characteristics] It prefers mild conditions and tolerates cold, and fears high temperatures and excessive moisture. It can overwinter safely under natural conditions. Because its roots are deep and long, it often grows on shady, moist mountain slopes with deep soil layers. In its place of origin, Saposhnikovia divaricata forms only leaf clusters in the first year, and bolts, flowers and sets seed in the second year, but the seed germination rate is relatively low. In the third year all plants bolt, flower and set seed, and the germination rate is relatively high. However, after bolting and setting seed, the roots rapidly become lignified and hollow, and the plants are also prone to dying.
[Planting Techniques]
1. Land selection and land preparation: Saposhnikovia divaricata has thick, long roots and prefers warmth and moisture, so it is advisable to choose sandy loam with deep, loose and fertile soil and convenient drainage and irrigation. In the selected land, apply 5000 kg of barnyard manure or farmyard manure, crush it finely and spread it evenly, and make flat beds 1 m wide.
2. Propagation methods: The roots of Saposhnikovia divaricata have adventitious buds and can be propagated by cuttings. In recent years, because cultivation by seed sowing often results in missing plants and broken rows, the root-segment cutting propagation method has been adopted. (1) Root-segment propagation 1) Root-segment propagation for raising seedlings: After the beginning of spring, in early to mid-March, in a sheltered, sunny place, dig a seedling-raising pool 35 cm deep and 1.3 m wide, with the length depending on circumstances. Mix sand or furnace ash with fertile soil evenly, fill it into the pool to a depth of about 20 cm. In the fields of Saposhnikovia divaricata to be harvested in early spring or in the seed fields left from last year, dig out the Saposhnikovia divaricata. Select thick, uniform and robust root strips, tie them into small bundles, and transport them to the side of the seedling-raising pool. Cut them in sequence into small segments of 3.5-5 cm, with the upper ends facing upward, and insert them vertically or slightly obliquely into the pool, with a slight gap between them. After the whole pool is planted, or immediately after planting, level it and cover lightly with soil. Pour 30-40 degrees C water into the pool, watering thoroughly at one time, place a few bamboo or wooden poles horizontally and vertically on the surface of the pool, and cover with plastic film. If the nighttime temperature is low, straw curtains can be placed over the plastic film. Seal the edges of the film firmly with wet mud. On sunny and warm days, uncover the straw curtains, sweep away the grass debris, pat off the water droplets inside the film, and let sunlight enter the pool as much as possible to increase the temperature inside the pool. In early to mid-April, adventitious buds will sprout from the upper ends of the root segments, and they can be transplanted in time. The products harvested from root-segment propagation can be used as raw materials for pharmaceutical factories or directly sliced and sold as decoction pieces. As Chinese medicinal material, it is not yet accepted, but the production benefit is high. 2) Field cultivation by root-segment propagation: Before transplanting, first irrigate the seedling-raising pool once, then dig out the seedlings with a small shovel, and never pull them out by hand. Transport the seedlings to the field. Dig holes at a spacing of 20-25 cm between plants and rows, plant vertically into the field, and cover lightly with soil. When transplanting, be sure to plant upright into the holes; otherwise there will be too many lateral roots, affecting the commercial quality of the medicinal material. After planting, water once, and water again two or three days later. Hoe shallowly to level the soil. Before long, the seedlings will emerge from the soil.
(2) Seed propagation: divided into direct sowing or seedling transplanting. When introducing the plant, if seeds are in short supply, seedling transplanting is usually adopted, but in large-scale production cultivation, direct sowing is preferable. The seed germination rate is relatively low, generally about 50%. Soak the seeds, mix with sand, and after accelerating germination at 20-25 degrees C, sow in spring. With sufficient soil moisture, seedlings can emerge about one week after sowing. If the temperature is below 20 degrees C, it takes more than 10 days for seedlings to emerge. 1) Direct sowing: In the northern spring-drought regions, sow before the land freezes in late autumn, or in southern regions after the land thaws in early spring. Where spring is not dry, sow in North China in April and in Northeast China in mid-May. First draw rows and open furrows at a row spacing of 16-20 cm, 1-1.5 cm deep, scatter the seeds evenly into the furrows, cover with 0.7-1 cm of soil, press lightly, then water, and take care to keep the soil moist to facilitate seedling emergence. The sowing rate is 1-1.5 kg of seed per mu. Generally, autumn sowing gives more uniform seedling emergence than spring sowing. 2) Raising seedlings: Choose a sunny place and make flat beds 0.9 m wide, sow from late March to late April, by drilling or broadcasting. For drilling, use a row spacing of 10 cm, open shallow furrows, scatter the seeds evenly into the furrows, cover with soil and seal it, press lightly, and sprinkle water with a watering can; or before sowing, irrigate the sunny bed thoroughly, and sow after the water has seeped down. For broadcasting, after sowing, sift a thin layer of fine soil over the surface. Covering the sowing bed with plastic film or straw curtains helps retain warmth and moisture, and can accelerate seed germination and seedling emergence. When the seedlings are about 6 cm tall, dig them up together with the surrounding soil and plant them out in the field (the method is the same as field cultivation by root segments), and water in time to ensure survival. When the transplanted seedlings have produced new roots and the leaves begin to expand, loosen the soil gently once, and do a good job of preserving soil moisture and protecting the seedlings to obtain a high yield.
3. Field management
(1) Seedling hardening: Before emergence in directly sown land, the bed surface should be kept moist; after emergence, weeds should be removed and the soil loosened frequently. After the seedlings emerge completely, water less and hoe frequently. This enables the roots to penetrate deeply.
(2) Topdressing and watering: Thin the seedlings when they are 3-6 cm tall; when the seedlings are about 10 cm tall, in combination with loosening the soil and weeding, set the plants at a spacing of 7-10 cm. When the seedlings are about 16 cm tall, apply 20 kg of superphosphate and 10 kg of ammonium nitrate per mu. When loosening the soil, weeding or topdressing, be careful not to damage the stems, so as not to affect the yield. Before the rainy season, carry out intertillage and hilling to prevent lodging. Before the clustered leaves close the rows, in combination with intertillage, apply one topdressing of cake fertilizer or compound fertilizer (50 kg of well-fermented cake fertilizer per mu, or 15-25 kg of compound fertilizer). After application, hoe shallowly to level the soil and water. After autumn, if it is dry, water several times, but there must not be too much water; too much will cause a mass of lateral roots and affect quality.
(3) Removing bolting stems: In the first year of growth, the plants only grow basal leaves and rarely bolt and flower; from the second year they begin to bolt and flower. Except for those kept for seed, the bolting stems should be removed in time to prevent effects on yield and quality.
(4) Pests and diseases and their control 1) Old World swallowtail (Papilio machaon Linnaeus): belongs to the Lepidoptera, Papilionidae. It occurs and causes damage in the Beijing area from June to September, and the larvae bite and eat leaves and flower buds. Control methods: manual capture and killing, or spraying with 800-fold dilution of 90% trichlorfon once every 5-7 days for 2-3 consecutive times; spraying with 300-fold dilution of 19 Bacillus thuringiensis (containing 10 billion spores per gram) can also be used for control. 2) Graphosoma rubrolineata [Graphosoma rubrolineata]: belongs to the Hemiptera, Miridae. It occurs and causes damage in northern regions from June to August. Adults and nymphs suck sap, causing poor plant growth. Control methods: manual capture and killing, or spraying with 800-fold dilution of 90% trichlorfon.
4. Selection and breeding of good seed: When harvesting, select those that grow well, have no pests or diseases, and have straight branches and thick, robust roots as seedlings for the seed field, and plant them separately in the seedling seed field. When they bolt and flower, select the seeds set on the top of the main stem or on the primary branches in the middle; among these, the seeds in the middle of the umbel, or after the flowers are cut off, the seeds threshed from the remaining parts are good seed. Plump seeds have a high germination rate.
[Harvesting and Processing] Saposhnikovia divaricata propagated by root segments can be harvested in the same year; the roots are thick and long, not hollow, of good quality and high yield. After November, when the stems and leaves wither, it can be dug and harvested. When digging, first dig a deep trench at one end of the bed, then dig out the Saposhnikovia divaricata roots in sequence and dry them in the sun. After the leaves wither, they can be rubbed off. Tie the roots into small bundles and dry them until completely dry. Because it is not easy to dry them after winter begins, the drying method is often used. Some can be harvested before the seedlings sprout the following year. But if one is slightly late, hollowing occurs and quality is reduced. Saposhnikovia divaricata propagated by seed can be harvested after two years of growth after sowing. Harvest in late autumn after the plants wither or in early spring before new shoots appear. When digging the roots, be careful not to damage the roots; after digging them out, remove the remaining stems and soil, and dry them in the sun for later use. Saposhnikovia divaricata is best when thick and long, firm, free of residual leaves and free of impurities.