Detailed Explanation of the Key Points of Standardized Cultivation Techniques for Gastrodia elata
Gastrodia elata, also known as Dingfengcao, is an orchid family plant and a traditional precious Chinese medicinal herb. Its tuber is used as medicine, and it has the effects of tonifying qi and relieving spasms, calming the liver and extinguishing wind, and settling fright and dispelling dampness. It can treat dizziness, numbness of the limbs, epilepsy, infantile convulsions, hypertension, otogenic vertigo, and other conditions. Gastrodia elata is mainly produced in Guizhou, and is also produced in Yunnan, Sichuan, Guang...
Gastrodia elata, also known as Dingfengcao, is an orchid family plant and a traditional precious Chinese medicinal herb. Its tuber is used as medicine, and it has the effects of tonifying qi and relieving spasms, calming the liver and extinguishing wind, and settling fright and dispelling dampness. It can treat dizziness, numbness of the limbs, epilepsy, infantile convulsions, hypertension, otogenic vertigo, and other conditions. Gastrodia elata is mainly produced in Guizhou, and is also produced in Yunnan, Sichuan, and Guangxi. Trial plantings have also been carried out in northern Guangdong and northwestern Guangdong.
I. Ecological Characteristics
1. Relationship between the growth of Gastrodia elata and Armillaria mellea. Gastrodia elata is a peculiar plant with no roots and no green leaves. Its tuber remains hidden in the soil year-round and cannot carry out photosynthesis. Because it has no organs to directly absorb soil nutrients or manufacture nutrients itself, it mainly relies on a wild fungus called "Armillaria mellea" to supply nutrients in order to grow, develop, and reproduce normally. Therefore, cultivating Armillaria mellea is the primary task in cultivating Gastrodia elata.
2. Growth characteristics of Armillaria mellea. Armillaria mellea is a saprophytic fungus of the genus Armillaria in the family Physalacriaceae. In mountain forests, wild Armillaria mellea often grows on newly decaying tree stumps, roots, fallen trunks, and branches, especially in the moist places on both sides of streams and ditches, so wherever wild Gastrodia elata grows, there is wild Armillaria mellea. Armillaria mellea grows best in slightly acidic soil with a pH of 5.5-6. The developmental stages of Armillaria mellea can be divided into two parts: the mycelium and the fruiting body.
3. Growing environment of Gastrodia elata. Wild Gastrodia elata mostly grows in cool summer environments at an altitude of 1000-1800 m, with annual rainfall of 1400-1600 mm, relative air humidity of 80%-90%, soil humidity of 50%-70%, and air temperature not exceeding 25°C. Production practice has shown that artificial cultivation of Gastrodia elata can generally be carried out in areas at an altitude of 800-1800 m, but zones at an altitude of 1100-1600 m are more suitable. If soil temperature and humidity can be controlled artificially, Gastrodia elata can also be cultivated in low-altitude flatland areas and indoors, and it can also be cultivated in basements and air-raid shelters. Gastrodia elata likes to grow in loose, humus-rich, well-aerated, slightly acidic soil. It grows poorly in clay soil (such as wet yellow mud soil).
II. Cultivation Techniques
1. Site selection and land preparation. According to the cool-loving characteristics of Gastrodia elata, in high mountain areas above 1500 m in altitude, where temperatures are generally low and humidity is high, sunny slopes without shade should be selected; in low mountain areas below 1000 m in altitude, where temperatures are generally higher and drier, especially in summer and autumn when continuous high temperature and drought often occur, shady slopes or semi-shady forest areas should be selected; in areas between 1100-1600 m in altitude, where temperature and humidity are often between those of high mountain areas and low mountain areas, semi-shady and semi-sunny sparse forest slopes should be selected according to local climate conditions. Gastrodia elata does not have very strict soil requirements, but gravelly soil and sandy loam with deep soil layers, rich humus, loose fertility, and good drainage are preferable. Gastrodia elata has relatively high soil moisture requirements, and generally humidity above 50% should be maintained year-round, but excessively wet waterlogged land is also unfavorable for its growth. As for land preparation requirements, it is enough to cut down overly dense miscellaneous trees and bamboo groves above ground or remove large rocks, clear away soil and stone debris and weeds, and then directly dig holes or open trenches for planting.
2. Propagation methods include seed propagation and tuber propagation. At present, production mainly uses tuber propagation. However, regardless of whether seed propagation or tuber propagation is used, because Gastrodia elata must live symbiotically with Armillaria mellea to obtain fungal nutrients for reproductive growth, cultivation of Gastrodia elata should first involve cultivating Armillaria mellea well on wood (wood sticks), that is, cultivating fungus wood, and then planting.
(1) Cultivating fungus wood. Fungus wood refers to wood on which Armillaria mellea rhizomorphs have grown.
① Preparing fungus spawn. Sources of fungus spawn can be considered from several aspects: first, collecting natural wild fungus spawn; second, using effective old fungus wood that has already been used together for planting Gastrodia elata; third, cultivating new fungus spawn outdoors; fourth, cultivating pure fungus wood indoors.
② Selecting wood. There are many tree species on which Armillaria mellea can grow, and broadleaf forest tree species are generally used. According to experience from various places, commonly used tree species include: Quercus aliena, Quercus variabilis, chestnut, Qinggang walnut, (Chinese wingnut), Donggua poplar, plane tree, wild cherry, rowan, and other trees.
③ Cultivation period. Outdoor cultivation can be carried out from March to August. Usually March to April, before the trunks begin to grow, is better. When cultivating fungus wood from June to August, soil temperature is high and Armillaria mellea grows quickly, which can relatively shorten the cultivation time and maintain sufficient nutrients in the fungus wood, but attention should be paid to avoiding contamination by miscellaneous fungi. After September, air temperature drops, Armillaria mellea grows slowly, and it cannot be used that same year, so it is not suitable to carry out then. If conditions are suitable for cultivating fungus wood in all four seasons, cultivation can begin 2-4 months before planting Gastrodia elata.
④ Methods of fungus wood cultivation. Methods for cultivating fungus wood include heap cultivation, kiln cultivation, and fixed fungus wood cultivation. Relative to the latter, the first two methods are also called mobile fungus wood cultivation methods. The cultivated fungus wood can be taken and used as needed when planting Gastrodia elata.
Heap cultivation method: choose a site near where Gastrodia elata will be cultivated, and lay a layer of prepared new cut wood pieces one next to another on the ground, with the fungus wood heap about 60 cm wide. After the first layer is laid, sprinkle clean water on it, and evenly lay a layer of already cultivated spawn wood free of miscellaneous fungi. If there is not enough fungus spawn, place 1-2 small pieces of spawn wood between every two cut wood pieces, and scatter a small amount of dead branches, fallen leaves, or rice husk fragments as filler, then lay a second layer of cut wood with spawn wood and filler, and repeat this layer by layer in sequence. A total of 5-6 layers can be laid, and heap cultivation to a height of about 60 cm is sufficient.
Kiln cultivation method: dig soil in open forest land or other bare ground to make a kiln. Its size depends on the terrain and the amount of fungus wood to be cultivated. Generally, one kiln is suitable for cultivating 150-200 pieces, and more is not advisable.
(2) Planting Gastrodia elata
① Asexual propagation cultivation method. The planting method using Gastrodia elata tubers as propagation material is called the asexual cultivation method.
② Mobile fungus wood plus new wood companion planting method. Dig a kiln according to the specific conditions of the planting site. The kiln width should be 6-8 cm wider than the length of the fungus wood, and the kiln length is variable, preferably able to hold 5-20 pieces of fungus wood; the kiln depth depends on local conditions. Loosen the kiln bottom by 6-10 cm and shape it into a slope, then fungus wood can be laid and Gastrodia elata planted.
③ Sexual propagation method. The planting method using seeds as propagation material is called the sexual propagation cultivation method. The white-headed hemp and rice hemp produced by seed propagation are used as seed hemp, which have strong vitality, are not easily degraded, and have a large propagation coefficient, making this an important approach to cultivating Gastrodia elata.