What are the key points of standardized cultivation techniques for Scutellaria baicalensis?
Scutellaria baicalensis is a perennial herb, plant height 20-50cm, the main root is conical, about 10-30cm long, about 1-2cm in diameter, the outer bark is yellowish-brown, the interior is yellow. Stems are clustered, the base prostrate on the ground, slightly ascending or erect, much branched and fine, the plant is square, green or purple-green. Leaves are simple and opposite; the leaf blade is lanceolate, the apex acuminate or acute, the base rounded, the margin entire. The raceme is terminal, the flowers arranged densely and to one side; the calyx is tubular and densely covered with hairs on the outside; the corolla is purple, bilabiate; stamens 4, didynamous; pistil 1, the ovary deeply 4-lobed, with an orange fleshy disc below the ovary. Nutlets 4, ovate, black, with a tuberculate surface, about 1mm in diameter, enclosed within the persistent calyx. The flowering period is June-September, and the fruiting period is July-October.
Biological characteristics
Scutellaria baicalensis prefers a mild climate, is resistant to cold and tolerant of drought. It originally grew wild on hillsides, field ridges, and sunny dry places at forest edges. It has no strict requirements for soil; well-drained, fertile sandy loam is best, and it can be planted on thin hilly land as well. Low-lying waterlogged land is not suitable for planting.
Cultivation techniques
1. Land preparation and fertilization: Choose loose, fertile sandy loam land with irrigation conditions and deep soil layers. If conditions permit, apply 2000-2500kg of farmyard manure per mu, crush it finely and spread it in the field; alternatively, 50kg of compound fertilizer and 25kg of phosphate fertilizer per mu can be used as base fertilizer. Deep plow 20-24cm, harrow fine and level, make flat beds 90cm wide, and open drainage ditches well. When the land is dry, first irrigate the bed, and after the water seeps down and the surface soil is slightly dry and loose, sow the seeds.
2. Propagation methods
(1) Seed propagation. For spring sowing, between “Spring Equinox” and “Pure Brightness” for summer sowing, between “Summer Solstice” and “Beginning of Autumn&rdquo. Direct sowing. On the prepared bed surface, open furrows 1cm deep at a row spacing of 24cm, mix the seeds with fine sand, sow evenly into the furrows, cover with 0.5cm of soil, rake level, and press lightly so that the seeds and soil are closely combined. Keep the bed surface moist; seedlings emerge about 10 or more days after sowing. The seeding rate is 3kg per mu.
(2) Seedling raising and transplanting. Around “Pure Brightness&rdquo, on the prepared bed surface, open furrows 0.5cm deep at a row spacing of 12cm, mix the seeds with fine sand and scatter them into the furrows, cover with soil and rake level, press lightly, and cover the top with a layer of grass or wheat straw to keep the surface soil moist. Use about 5kg of seeds per mu for seedling raising. Transplanting: spring-sown seedlings are transplanted around “Beginning of Autumn&rdquo, and summer-sown seedlings are transplanted after germination the following year. In the prepared field, open furrows 12-15cm deep at a row spacing of 24cm, place seedlings at a plant spacing of 12cm, with the bud head upward, about 15cm below the ground surface, keep the roots upright, cover with soil, press firmly, and make the roots closely contact the soil. Water after planting to ensure survival.
3. Field management
(1) Management during the seedling stage. After sowing, keep the ground moist to facilitate seedling emergence. After the seedlings emerge, remove the covering weeds, and lightly loosen the surface soil to keep the ground loose and the lower layer moist, which helps the roots extend downward. When the seedlings grow to 4cm high, shallow hoe once, and thin out the overly dense weak seedlings. In seedling beds, keep seedlings at a spacing of 6cm; for direct sowing, thin to a plant spacing of 12cm. After final thinning, hoe whenever there are weeds, water in dry weather, and pay attention to preventing waterlogging in the rainy season; water must not accumulate in the field.
(2) Management after transplanting. After survival, pay attention to hoeing and loosening the soil to keep the field clean. Scutellaria baicalensis has relatively strong drought resistance. In cases of severe drought or after topdressing, it may be watered appropriately; generally it does not need frequent watering. After “Beginning of Summer&rdquo, apply 1000kg of farmyard manure plus 150kg of plant ash per mu, mix evenly, open shallow furrows between the rows and apply, cover with soil and level it, then weed frequently to keep the field free of weeds. It generally flowers in June and can bloom until September. The seed maturation period is inconsistent, and the seeds fall as they mature, so if collecting seeds, harvest them in time and store them for later use. If seed collection is not needed, the flower buds can be removed to favor root growth.
Pest and disease control
According to many years of production practice and observation. At present, there are not many pest and disease occurrences in Scutellaria baicalensis, and special control is generally not needed. Only in very few plots has leaf blight been found.
Leaf blight: The pathogen is a type of imperfect fungus among the fungi. It mainly damages leaves. The symptoms extend inward from the leaf tip or leaf margin. Irregular dark brown lesions appear, rapidly spreading from top to bottom, causing the leaves to wither and die. The disease is prone to occur in hot and rainy seasons.
Control method: In winter, dispose of diseased residual plants; pull out the diseased residual plants infected with the pathogen together with the roots and burn them to eliminate overwintering pathogens. In the early stage of the disease, spray with 50% carbendazim wettable powder 1000-fold solution or 1:1:120 Bordeaux mixture, once every 7-10 days, for 2-3 consecutive times to cure it.
Harvesting and processing
Generally harvested two years after sowing, or it can also be harvested in the same year. Around ”Frost's Descent, choose a sunny day to dig, remove the stems, leaves and soil, and sun-dry or air-dry. During drying, prevent moisture and rain, so as not to turn green upon contact with water and finally deteriorate and turn black, affecting quality. After drying, remove all rootlets, and it can then be used as medicine. Every 3-4kg of fresh roots can be processed into 1kg of dried goods, and generally 200-300kg of dried goods can be harvested per mu. Dried goods are best when the strips are thick, the texture is firm, and the interior color is yellow.