Detailed Explanation of Bletilla striata Planting Techniques and Methods

I. Overview Bletilla striata is the dried rhizome of Bletilla striata, a plant of the genus Bletilla in the orchid family. Also known as bai gen, di luo si, bai ji wa, yang jiao qi, lian jiao ji cao, zi lan, etc. It is a commonly used traditional Chinese medicine with functions such as tonifying the lungs and stopping bleeding, reducing swelling and promoting tissue regeneration. It mainly treats pulmonary tuberculosis with coughing of blood, bronchiectasis with hemoptysis, gastric ulcer with hematemesis, hematuria, hematochezia, etc., and is used externally for traumatic bleeding, burns and scalds, chapped hands and feet, and other conditions. Nowadays, adhesive film blocks made from Bletilla striata are used in liver and spleen surgery, applied to the incision site to replace hemostatic forceps, with excellent results. It has a rapid coagulation effect and can serve as a plasma substitute, and is widely used in surgical operations. It is mainly produced in Sichuan, Yunnan, Shaanxi, Anhui, and Hubei. It is also cultivated in Guizhou.

II. Morphological Characteristics Perennial herb. Plant height 30-60 cm. Tubers fleshy, white, with 2-3 forks in a water caltrop shape, with fibrous roots, often several growing together. Raceme terminal, usually with 3-8 flowers; flowers pale purplish-red, petals irregular. Capsule cylindrical, with 6 longitudinal ridges, slightly pointed at both ends. Seeds tiny, numerous. Flowering period April-May, fruiting period July-August. There are two types of Bletilla striata; another has yellowish-white flowers and linear-lanceolate leaves, which is Bletilla striata var. angustifolia. Among the purplish-red flowered types, there are further distinctions between large and small varieties, with the large variety having higher tuber yield.

III. Growth Characteristics Prefers a warm, cool, and relatively shady and moist environment; not cold-tolerant. Requires fertile, loose, and well-drained sandy loam or humus loam. Requires cultivation on shady slopes or relatively shady and moist plots.

IV. Planting Techniques 1. Site selection and land preparation: Choose loose, fertile sandy loam and humus loam, in a warm, slightly shady and moist environment; not cold-tolerant. When planting on well-drained mountain land, choose a shady slope of virgin land for planting. After the previous crop is harvested, plow the soil to a depth of more than 20 cm. Before plowing, trifluralin can be used to kill soil weed seeds. Apply barnyard manure and compost; apply 1500-2000 kg of farmyard manure per mu. If no farmyard manure is available, broadcast 50 kg of ternary organic compound fertilizer. Then plow again to mix the soil and fertilizer evenly. Before planting, do a shallow plowing once, break up the soil finely, rake it level, and make raised beds 130-150 cm wide. 2. Propagation methods: Bletilla striata is difficult to propagate by seed, but easier by tuber division. At harvest from September to November, select tubers of the current year that have old stems and young buds as seed stock. In the south, it is best to plant immediately after digging; in the north, store the seed stock until the following spring for planting. Storage method: After digging up the Bletilla striata tubers, place them in a ventilated and dry place to air-dry for several days. Then, mix 1 part of seed tubers with 2-3 times their volume of clean, slightly dry fine river sand and store in a corner of a ventilated, cool, and dry room. A small number of seed tubers can be mixed with fine sand and stored in a wooden box. Do not cover the top of the box, and check regularly; deal with any mold promptly. For planting, areas south of the Yangtze River mostly use autumn planting in September-October; the northwest region is suitable for spring planting in March-April. For autumn planting, select tubers of the current year with young buds and cut them into small pieces, each piece needing 1-2 buds. Then, at a row spacing of 33 cm and plant spacing of 23-25 cm, dig holes 10-13 cm deep, smooth the bottom of the holes, and plant 3 seed tubers per hole. When planting, point the bud tips outward, arrange them in a staggered triangle, and place them flat at the bottom of the hole. After planting, cover with fine fertile soil or wood ash and soil, pour once with dilute human and livestock manure water, and cover with soil level with the bed surface. Firm the soil, water, cover with grass, and keep it moist regularly. Seedlings emerge in March-April. Use 100 kg of seed stock per mu, about 6000 plants. 3. Field management (1) Cultivation and weeding: Bletilla striata has very strict weed control requirements in field management. After planting, spray acetochlor for pre-emergence closure. Cultivation and weeding are generally done 4 times a year. The first time is after full emergence in April; the second time is during vigorous growth in June, because weeds grow quickly at this time and Bletilla striata seedlings are short, so weeds must be removed promptly to avoid weed infestation. The third time is in August-September; the fourth time is combined with harvesting intercropped crops, loosening the bed surface and removing weeds. Each cultivation should be shallow to avoid damaging the roots. (2) Topdressing: Bletilla striata likes fertilizer. During the growing period, spray once a month with potassium dihydrogen phosphate or dilute human and livestock manure water, 1500-2000 kg per mu. In August-September, apply a slightly more concentrated liquid fertilizer as topdressing; superphosphate can also be mixed with compost and composted, then broadcast on the bed surface, combined with the third cultivation and weeding, and covered with soil pressed into the bed. (3) Irrigation and drainage: Bletilla striata likes shady and moist conditions, and the cultivation site should be kept moist regularly; water promptly in case of drought. In July-September, water once in the morning and once in the evening. Bletilla striata is also afraid of waterlogging; during the rainy season or after each heavy rain, dredge ditches promptly to remove excess standing water to avoid root rot. Bletilla striata grows slowly and has a long cultivation period. In the first two years, short-term crops can be intercropped between rows to make full use of the land and increase income. 4. Pest and disease control (1) Root rot: Mostly occurs in the rainy seasons of spring and summer in the south. Control methods: Pay attention to drainage and waterproofing, and dig drainage ditches deep. (2) Cutworms and wireworms: There are many underground pests; a small amount of camphor powder diluted with water can be sprayed to drive them away; for diseases, carbendazim or chlorothalonil can be used, diluted with water and sprayed; manual capture and trapping or poisoned soil can also be used, applying di chong jue into the seedling bed. Use 50% zinc phoxim emulsifiable concentrate at 700 times dilution to irrigate the seedling bed. V. Harvesting and Processing After harvesting Bletilla striata seeds, harvest in September-October of the 3rd or 4th year when the aboveground stems wither. At this time, 8-10 underground rhizomes have grown. Dig up the tubers, remove the soil, and process them. Pick off the tubers individually, select and keep tubers with new stems for seed use, cut off the stems, soak in clean water for 1 hour, wash off the soil, put in boiling water and boil for 5-10 minutes until there is no white core inside the tubers, then take out and sun-dry or dry over a fire until completely dry. Remove the coarse skin and fibrous roots completely, and sift out impurities. Generally, 800-1000 kg of fresh product can be harvested per mu, which can be processed into 200-300 kg. Those that are large, plump, white, semi-transparent, and solid in texture are considered best.