What are the key points of high-yield cultivation techniques for Salvia miltiorrhiza (Danshen)

1. Site selection and land preparation According to the growth habits of Salvia miltiorrhiza, choose a plot with sufficient sunlight, good drainage, convenient irrigation, and a not-too-high groundwater table. The soil should be deep, loose in texture, and a sandy loam with a pH of 6-8. Plots with heavy clay soil, low-lying water accumulation, or shading should not be planted. Salvia miltiorrhiza is a deep-rooted perennial plant. Before planting, apply sufficient slow-release, long-lasting barnyard manure, cake fertilizer, or chemical fertilizer, mainly phosphorus fertilizer, as base fertilizer. Generally, apply 5000 kg of decomposed farmyard manure, 50 kg of superphosphate, or 20 kg of diammonium phosphate per mu, and deep plow 30-40 cm. Be sure to break through the plow pan to facilitate root growth and development. Rake fine and level. In the north, make flat beds 1.5-2 m wide; in the south, make raised beds 15-20 cm high. Dig drainage ditches around the plot so that it can be irrigated in drought and drained in waterlogging.</p><p></p><p>2. Selection of superior varieties</p><p>Under the same cultivation conditions, the yield and quality of different varieties vary greatly. Selecting good varieties is an agricultural measure with high benefit and quick results. The new tetraploid line Salvia miltiorrhiza 61-2-22 not only has good field agronomic traits and vigorous growth, but the tanshinone content of the root medicinal material is also much higher than that of the original plant and other tetraploid lines. While the yield is high, the chemical composition content is also high, meeting the ideal requirements, and it should be vigorously promoted in production.</p><p>3. Transplanting</p><p>After spring sowing, seedlings can be transplanted after about 75 days of cultivation. It can be planted in spring or autumn. Spring planting is carried out in mid-May, and autumn planting in late October. Earlier is better than later; early transplanting leads to early rooting and early greening the next year. When planting, dig holes on the bed surface at a row spacing of 33&times;23 cm. The depth of the holes depends on root length. Apply an appropriate amount of manure at the bottom of the hole as base fertilizer, mix evenly with the hole soil, and then plant 1-2 seedlings propagated from seeds per hole. The planting depth should be based on the original natural growth depth of the seedling, with the heart bud slightly exposed. After planting, water thoroughly to settle the roots. For cuttings, plant 1 plant per hole using the same method and planting density.</p><p>4. Propagation methods</p><p>Mainly root division and root crown propagation, and seed sowing and cutting propagation can also be used.</p><p>(1) Root division propagation In autumn at harvest, select current-year Salvia miltiorrhiza roots with a diameter of 0.7-1 cm, purple-red color, no pests or diseases, and full development as seed roots, and store them in wet sand until the next spring. In early spring from March to April, cut the seed roots into 4-6 cm segments, and according to the specification of row spacing, plant spacing, and depth of 35 cm &times; 25 cm &times; 6 cm, place the cut seed roots vertically into the holes, one segment per hole, with the thick end facing up. Do not place them upside down. Cover with about 2 cm of soil; it should not be too thick, otherwise it will affect emergence. Use about 50 kg of seed roots per mu. Planting with root segments results in late flowering, and it is difficult to harvest seeds in the same year, but the roots grow faster and the medicinal material yield is high.</p><p>(2) Root crown propagation At the time of Salvia miltiorrhiza harvest, select robust, disease-free plants, cut off the thick roots for medicinal use, and use the fine roots together with the root crown and heart leaves as planting material for planting. Large seedlings can be divided into 2-4 plants according to the natural growth condition of buds and roots, and then planted. Wild Salvia miltiorrhiza can also be dug up; cut off the thick roots for medicinal use, and plant the fine roots together with the root crown. The plant and row spacing are the same as for root division propagation, and the time should be in late autumn or early spring. With root crown propagation, it can be harvested the next year after planting, with a short production cycle and good economic benefit.</p><p>(3) Cutting propagation In the north from June to July, and in the south from April to May, select robust, disease-free Salvia miltiorrhiza branches, cut them off at ground level, cut them into 13-16 cm segments, and make the lower cut close to the stem node in a horseshoe shape. Remove the lower leaves, and at a row spacing of 20&times;10 cm, insert the cuttings obliquely into the seedbed to a depth of 1/2-2/3 of the cutting, press the soil firmly, and leave 1-2 leaves above ground. For domestic Salvia miltiorrhiza, cut and insert immediately; they should not be left for long, otherwise the survival rate of the cuttings will be affected. After insertion, keep the soil moist and provide appropriate shade. In 15-20 days, new roots will grow from the lowest stem node. When the roots are 3 cm long, set them out in the field.</p><p>(4) Seed propagation Salvia miltiorrhiza seeds are small, with a germination rate of about 70%. Direct sowing often results in uneven emergence, so the seedling transplanting method is mostly used. Seeds should be selected from those matured after June, and sown immediately after collection or sown in September. In the Beijing area, seeds are generally sown in seedbeds in March, either in drills or broadcast. For drilling, the row and plant spacing is 30&times;20 cm, the furrow depth is 1-1.3 cm, and the seeds are mixed with river sand and evenly sown in the furrows, then covered with 0.5-0.7 cm of soil. For broadcasting, the seeds can be evenly scattered on the ground and pressed once with the foot so that the seeds adhere closely to the soil; there is no need to cover with soil. The sowing rate is about 0.5 kg per mu. After sowing, cover with plastic film to keep warm and moist. When the soil temperature reaches about 20℃, seedlings emerge in 15-20 days. When the seedlings have 3-5 true leaves, thin them if they are found to be too dense. The thinned seedlings can be planted outside and cultivated. After 2 months of growth after sowing, they can be transplanted.</p><p>Among the above 4 propagation methods, using root crowns as propagation material gives the highest yield. Next is root division propagation.</p><p>5. Field management</p><p>(1) Cultivation, weeding, and topdressing</p><p>In early April after all seedlings have emerged, carry out 1 cultivation and weeding. Shallow loosening of the soil is advisable, and then immediately apply 1 light application of dilute human and livestock manure water, 1500 kg per mu; the 2nd time is from early May to early June. After cultivation, apply 1 application of decomposed human manure and urine, 2000 kg per mu, plus 50 kg of cake fertilizer; the 3rd time is from late June to mid- and late July. Combined with cultivation and weeding, apply a heavy application of decomposed, slightly concentrated manure, 3000 kg per mu, plus 25 kg of superphosphate and 50 kg of cake fertilizer, to promote root growth and development. The fertilization method can be furrow application or hole application, and after application, cover with soil to cover the fertilizer.</p><p>1. Growth habits of Salvia miltiorrhiza roots</p><p>Salvia miltiorrhiza is a perennial herbaceous plant with a well-developed root system that can reach 60-80 cm in depth, so deep, loose sandy loam is most favorable for root growth. When the soil is too sticky and aeration and drainage are poor, root rot is often caused, leading to wilting of the whole plant. The root sprouting ability is relatively strong, so root division propagation can be used. The upper and middle segments of the root strips sprout and root faster than the lower segments. Studies show that Salvia miltiorrhiza roots grow along with the growth of the aboveground part. Later, as the temperature gradually decreases, aboveground growth gradually slows down, nutrients are transferred downward, and root growth becomes more rapid.</p><p>2. Fertilizer requirements of Salvia miltiorrhiza</p><p>Salvia miltiorrhiza plants have a strong ability to absorb fertilizer. Relying on their powerful root system, they can absorb nutrients from the surface and deep layers of the soil. In general soil with medium fertility, they can grow and develop well, and the effect is even better when more base fertilizer is applied together with nitrogen topdressing. When nitrogen, phosphorus, and potassium are severely deficient, Salvia miltiorrhiza plants will show certain physiological abnormalities. In cases of severe nitrogen deficiency, the leaf color of the plants gradually changes from dark green to light green in the early stage, and plant growth is slow; in severe cases, the growing point does not develop or even necroses, no new leaves grow, old leaves gradually turn yellow and withered, roots are small, and medicinal material yield is very low. When phosphorus is deficient, the leaves are green, sometimes reddish-brown. In the early stage, there are obvious brown spots on the leaves; later the spots enlarge and become scorched, the leaves sometimes twist and curl, and heart leaf growth is slow. When potassium is deficient, the plant leaves are green to dark green, the leaves are broad and large, the petioles are slender, tender, and weak, showing excessive vegetative growth. Sometimes the edges of old leaves have relatively large brown spots, the veins are dark green, and other parts are light green, showing obvious mottling.</p><p>3. Fertilization techniques for Salvia miltiorrhiza</p><p>Because Salvia miltiorrhiza is a fertilizer-loving medicinal plant, sufficient base fertilizer must first be applied at sowing; the base fertilizer is mainly farmyard manure and miscellaneous fertilizers, such as decomposed pig or sheep pen manure or burnt mud ash, etc. The application rate is 1000-1200 kg per 667 sq m (1 mu). After mixing evenly with the soil, prepare the land finely and level it. In addition to base fertilizer, during plant growth, topdressing should also be applied at least 2-3 times. In the early growth stage, topdressing is mainly nitrogen fertilizer or human and livestock manure and urine; in the middle growth stage, apply fertilizer according to the seedlings; after autumn, apply a heavy application of root-growing fertilizer, preferably a mixed phosphorus and potassium fertilizer such as superphosphate.</p><p>(2) Removal of flower stems</p><p>From late April to May, Salvia miltiorrhiza will successively bolt and flower. In order to concentrate nutrients on root growth, except for seed-producing plots, all flower stems should be cut off. The earlier the better.</p><p>(3) Drainage and irrigation</p><p>Salvia miltiorrhiza is most averse to water accumulation. In the rainy season, clear ditches and drain water in time; in dry weather, carry out furrow irrigation or watering in time, and promptly remove excess accumulated water to avoid waterlogging.</p><p>Pest and disease control of Salvia miltiorrhiza</p><p>1. Diseases</p><p>(1) Leaf blight</p><p>Leaf blight starts on the lower leaves of the plant and gradually spreads upward. In the early stage of the disease, brown, round small spots appear on the leaf surface. The spots continuously expand, the center becomes grayish-brown, and finally the leaves scorch and the plant dies. It occurs in early May and continues until late autumn, and is most serious in June-July. Control methods: 1. Select disease-free, robust planting material, and before planting soak the seeds for 10 minutes in Bordeaux mixture (1:1:100) for disinfection. 2. Strengthen management, increase the application of phosphorus and potassium fertilizers, open ditches and drain water in time, reduce humidity, and enhance disease resistance. 3. In the early stage of the disease, spray 60% zineb 600-fold solution or 50% carbendazim 800-fold solution.</p><p>(2) Sclerotinia disease</p><p>The pathogen of Sclerotinia disease first attacks the stem base, buds, and rhizome of the plant. The infected parts turn brown and gradually rot. On the surface of the diseased parts, nearby soil surface, and inside the stem base, gray-black mouse-like sclerotia and white mycelium are produced. The upper part of the diseased stem and leaves gradually turn yellow, and finally the plant dies. Control methods: 1. Keep the soil dry and drain accumulated water in time. 2. Diseased land can be planted as paddy field to drown the sclerotia, and then used as a Salvia miltiorrhiza cultivation field. 3. During the disease period, mix 0.5 kg of 50% chloronitroamide with 10 kg of lime to make a sterilizing agent, and scatter it on the stem base of diseased plants and nearby soil to prevent the spread of the disease. 4. Irrigate with 50% procymidone 1000-fold solution.</p><p>(3) Root rot</p><p>In plants affected by root rot, the fine roots first develop brown dry rot, which gradually spreads to the thick roots. When the root is cut crosswise, a clear brown color can be seen on the cross-section, that is, vascular bundle lesions. In the later stage, the roots rot, the aboveground part of the plant wilts and dies, and finally the entire plant dies. It mostly occurs from May to November. Control methods: 1. Implement crop rotation and choose hillside land with high, dry terrain for planting. 2. Strengthen management, increase the application of phosphorus and potassium fertilizers, loosen the soil, promote plant growth, and improve disease resistance. 3. In the early stage of the disease, spray 50% thiophanate 800-1000-fold solution.</p><p>(4) Root-knot nematode disease</p><p>This is a parasitic disease. After root-knot nematodes invade the roots, they stimulate host cells to divide faster, causing the damaged parts of the root system to form tumor-like swellings. The swellings on various parts of fine roots and thick roots vary in size and shape. This is a notable feature of nematode disease. The tumor-like bodies are initially yellowish-white with a smooth surface, later turn brown, and finally break and rot. When the galls are cut open, they are transparent and contain colorless transparent small granules. After nematode parasitism, the root function of the plant is damaged, affecting nutrient absorption, causing the aboveground part of the plant to die. Control methods: 1. Paddy-upland rotation is beneficial for drowning nematodes and reducing damage. 2. Choose fertile soil and avoid planting in plots with excessively sandy soil to reduce the occurrence of nematode disease. 3. Use 2-3 kg of 80% dibromochloropropane plus 100 kg of water, open furrows and apply it into the soil 15 days before planting, then cover with soil to prevent evaporation of the liquid and improve the control effect.</p><p>2. Insect pests</p><p>Cabbage looper Cabbage looper generally occurs in summer and autumn. The larvae bite and feed on leaves, and in severe cases eat all the leaves. Cabbage looper has 5 generations per year. The second-generation larvae begin to damage Salvia miltiorrhiza leaves in June-July, and the damage is most serious from late July to mid-August. Control methods: 1. After harvest, burn diseased plants in a centralized manner to kill overwintering eggs. 2. Hang black light lamps in the field to trap and kill adult moths. 3. When larvae appear, spray with 10% fenvalerate 2000-3000-fold solution or 90% trichlorfon 800-fold solution. Spray once a week, continuously 2-3 times.</p><p>Harvesting, processing, and storage of Salvia miltiorrhiza</p><p>1. Harvesting and processing</p><p>(1) Seed harvesting and processing Salvia miltiorrhiza flowers and sets seed in the 2nd year after planting. From late May or early June, the seeds mature successively. The order of seed maturity is from bottom to top; the seeds in the lower part of the inflorescence mature first, and the seeds in the upper part mature later. Seeds must be harvested in time, otherwise they will scatter on the ground by themselves. When collecting seeds, if the seed-producing area is very small, they can be harvested in stages and batches. The calyxes of several lower nodes of the inflorescence together with mature seeds can first be stripped off, while the immature upper nodes are left for later harvest. If the seed-producing area is very large, when 2/3 of the fruit calyxes on the inflorescence have already turned from green to yellow but are not completely dry, cut off the entire inflorescence, then cut off the young tender top part, leave the mature seeds in the middle and lower parts, sun-dry for 3 days in the sun on a clear day, thresh, winnow clean, sun-dry, bag, and store in a cool, ventilated, dry place for later use. The seeds must be dried before storage, otherwise the germination rate will be affected.</p><p>(2) Harvesting and processing of medicinal material (roots) For vegetatively propagated Salvia miltiorrhiza, dig and harvest in autumn of the same year after frost or before sprouting in the next spring. For seed-propagated plants, dig and harvest after autumn of the 2nd year or before sprouting in the 3rd spring; the yield is high and the quality is good. Salvia miltiorrhiza roots go deep into the soil, are brittle, and break easily, so dig them on a clear day when the soil is half-dry. Dig a deep ditch from one end of the ridge; the depth depends on the root length. After all roots are exposed, carefully take out all roots plant by plant along the ridge, sun-dry in the field, remove soil, and transport back for processing. Do not wash with water. In the north, after digging, drying in the sun is sufficient. In the south, sun-dry to half-dry in the sun, gather and pile for &ldquo;sweating&rdquo;, 500-1000 kg of root strips per pile. After piling for 4-5 days, air the pile for 1-2 days. After airing the pile, carry out &ldquo;turning the pile&rdquo;, that is, rake down the roots on the surface layer of the pile as a whole and pile them below, and use the root strips from the inner layer of the original pile to pile on top, that is, exchange the positions of the inner and outer layers, so that the whole root pile &ldquo;sweats&rdquo; evenly, then cover with reed mats and continue piling until the inner core of the root strips changes from white to purple-black. Then spread the pile and sun-dry until completely dry, then use fire to singe off the fine fibrous roots on the root strips, place them neatly in bamboo baskets, and shake gently so that they rub against each other, removing the dust attached to the root strips and the fibrous roots not removed. The finished product is then stored in a dry, ventilated place to prevent mold and insects. Generally, the yield of dry goods is 200-250 kg per mu, and high-yield fields can reach 300-400 kg, with a drying rate of 30%.</p><p>2. Storage</p><p>The safe moisture content of commercial Salvia miltiorrhiza is 11%-14%, the suitable storage temperature is below 30℃, and the relative humidity is 70%-75%. Pack in gunny bags or baskets and store in the warehouse according to the above requirements. This product is brittle and breaks easily, so it must be protected from heavy pressure; it is prone to moisture and mold, and prone to insect damage. During storage, inspect regularly. If moisture or excessively high temperature is found, turn the stack and air it in time. If the insect situation is serious, fumigate with aluminum phosphide. Before high-temperature and high-humidity seasons, sealed oxygen extraction and nitrogen filling maintenance can be carried out.</p><p>Specification standards for Salvia miltiorrhiza</p><p>According to the medicinal material commodity specification standards formulated by the National Medical Products Administration and the Ministry of Health of the People's Republic of China, Salvia miltiorrhiza commodities are divided into two specifications: wild and cultivated.</p><p>1. Wild</p><p>General goods, dry. Cylindrical, short and thick strips, branched, mostly twisted, surface reddish-brown or red-yellow of varying shades, rough skin, mostly scaly, easy to peel off. Light and brittle. Cross-section red-yellow or brown, loose with cracks, showing white dots of veins. Slight odor, sweet and slightly bitter taste. No root crown, fibrous hairs, impurities, or mildew.</p><p>2. Cultivated</p><p>Grade I dry goods: cylindrical and long strip-shaped, occasionally branched. Surface purple-red or yellow-red, with longitudinal wrinkles. Solid texture, fine skin and plump. Cross-section grayish-white or yellow-brown. No fibers. Weak odor, sweet and slightly bitter taste. Mostly whole branches, with complete head and tail. The diameter of the upper and middle parts of the main root is more than 1 cm. No stem remnants, broken nodes, fibrous roots, impurities, insect damage, or mildew.</p><p>Grade II dry goods: cylindrical or long strip-shaped, occasionally branched. Surface purple-red or yellow-red, with longitudinal wrinkles. Solid texture, fine skin and plump. Cross-section grayish-white or yellow-brown, no fibers. Weak odor, sweet and slightly bitter taste. The diameter of the upper and middle parts of the main root is less than 1 cm, but not less than 0.4 cm. There are single branches and broken nodes from knocking, and no stem remnants, fibrous roots, impurities, insect damage, or mildew.</p><p>Identification of Salvia miltiorrhiza</p><p>1. Microscopic identification</p><p>(1) Root cross-section: 1. The cork layer consists of 4-6 rows of cells, most containing orange or light purple-brown substances, and sometimes rhytidome tissue can be seen. 2. The cortex is broad. 3. The phloem is relatively narrow, crescent-shaped. 4. The cambium is ring-shaped. 5. The xylem has 8-10 or more bundles, radially arranged. Vessels are more numerous at the cambium, arranged tangentially, and gradually toward the center the vessels appear in a single row. The xylem rays are wide, and fibers often exist in bundles in the central primary xylem.</p><p>(2) Powder: reddish-brown. 1. Stone cells are subrounded, subrectangular, or irregular, 20-65 &mu;m in diameter, up to 257 &mu;m long, wall thickness 5-16 &mu;m, some containing brown substances. 2. Vessels are reticulate and bordered-pitted. Reticulate vessel elements are long fusiform, with narrow and fine mesh openings, and perforations mostly located on the side walls. 3. Wood fibers are long fusiform, mostly present in bundles, with pits in oblique slit-like or cross-shaped form. 4. Cork cells are yellow-brown, sub square or polygonal in surface view, with slightly thick walls.</p><p>2. Physicochemical identification</p><p>(1) Take 5 g of powder, add 50 ml of water, boil for 15-20 minutes, cool, filter, concentrate the filtrate on a water bath to a viscous state, cool, add 3-5 ml of ethanol to dissolve, filter, and use the filtrate for the following tests: 1. Take several drops of the filtrate, spot on filter paper strips, and after drying, observe under ultraviolet light; it shows bright blue-gray fluorescence. Hang this paper strip in an ammonia bottle, take it out after 20 minutes, and observe under ultraviolet light; it shows light bright blue-green fluorescence. 2. Take 0.5 ml of the filtrate, add 1-2 drops of ferric chloride test solution; it shows dirty green.</p><p>(2) Take 1 g of this product powder, add 5 ml of diethyl ether, place in a stoppered test tube, shake, let stand for 1 hour, filter, evaporate the filtrate to dryness, add 1 ml of ethyl acetate to the residue to dissolve, as the test solution. Separately take reference medicinal material of Salvia miltiorrhiza, prepare a reference medicinal material solution by the same method. Separately take tanshinone IIA reference substance, add ethyl acetate to prepare a 2 mg/ml reference solution. Draw 5 &mu;l each of the above three solutions and spot on the same silica gel G thin-layer plate. The developing solvent is benzene:ethyl acetate (19:1). In the chromatogram of the test solution, spots of the same color appear at the positions corresponding to the chromatograms of the reference medicinal material and reference substance.</p>