Detailed Explanation of Dendrobium nobile Planting Methods and Techniques
Dendrobium nobile (scientific name: Dendrobium nobile Lindl), pronunciation: [jīn chāi shí hú], also known as Wanzhangxu, Jinchaishi, Bianjinchai, Bianhuangcao, Biancao, is a perennial herb, named for its resemblance to the hairpins worn on the head in ancient times. The stems grow in clusters, the upper part slightly flattened and slightly curved upward, 10~60 cm tall, up to 1.4 cm thick. It prefers to grow in warm, humid, semi-shaded and semi-sunny environments. The main native origins of Dendrobium are distributed in tropical and subtropical Asia, Australia and Pacific islands, with about 1000 species of Dendrobium worldwide. China has about 76 species, most of which are distributed in the southwest, south China, Taiwan, China and other places. The genus Dendrobium is the largest genus in the orchid family, with effects of nourishing yin and clearing heat, promoting body fluid and quenching thirst, used for treating damage to body fluids from febrile disease, thirst and dry tongue, deficiency heat after illness, etc.
Planting Methods
1. Site selection and land preparation
For Dendrobium nobile cultivation, a semi-shaded and semi-sunny environment should be chosen, with air humidity above 80% and winter temperatures above 0°C. The tree species should be living trees such as Huangjue trees, pear trees, camphor trees, etc., and should have thick bark, longitudinal grooves, high water content, dense branches and leaves, and thick trunks. Stone plots should also be in cool, moist areas, with moss growing on the stones and a small amount of humus on the surface. When planting Dendrobium, the plot should first be prepared. The basic requirements are: when planting Dendrobium on large rocks, holes should be drilled on the stone surface with a drill at a spacing of 30 cm x 40 cm between plants and rows, with a hole depth of 5~10 cm, and a small drainage outlet should be made on the lower side of the stone surface to prevent water accumulation from causing basal rot; when drilling holes, the moss on other parts of the stone surface should be protected. When planting Dendrobium on small gravel, remove weeds and miscellaneous branches in the field, reserve shade trees, and clear excess and overly dense small miscellaneous trees to help increase light penetration.
2. Propagation methods
Because Dendrobium nobile seeds are extremely small, with about 20,000 seeds in each capsule, they generally need to be cultured in a tissue culture room. In actual small-scale production, asexual propagation is commonly used, carried out in spring or autumn. Select plants with good growth vigor, no pests or diseases, well-developed root systems, and many sprouts that have grown for 1~2 years as stock plants, pull them up with roots, remove dead branches and broken branches, cut off overly long fibrous roots, keep old roots at about 3 cm, and divide them into several clumps according to the number of stems, with each clump having 4~5 stems, and they can be used as planting material.
3. Planting methods
Dendrobium nobile is best planted in spring (March~April) and autumn (August~September), and spring planting is especially more suitable than autumn planting. ① Stone-attached planting method. Choose places with humus in stone crevices and stone grooves under shady and moist forest, wrap the roots of the divided small clumps of Dendrobium seedlings with cow dung slurry, and stuff them into rock crevices or grooves, making sure to press them firmly when stuffing to avoid falling. If cultivating on gravel, the method is to lay the seedlings flat on the gravel, then press the middle and lower parts of the seedlings with stones, leaving the base and top exposed, with the standard being that they do not move in the wind. When planting Dendrobium around the stone surface, a small hole can be drilled with a drill; beforehand, 30:1 phosphate fertilizer can be mixed into fresh cow dung, add water and tread to mix, with the moisture level such that no water remains in the finger crevices when squeezed by hand, press the Dendrobium seedlings tightly against the small hole, and with one hand take the prepared cow dung and place it on the middle and lower parts of the Dendrobium seedling stems, so that the seedlings firmly attach to the stone. ② Tree-attached planting method. On relatively flat and thick trunks or in tree branch depressions, or every 30~50 cm, cut a shallow notch with a knife and peel off some bark, then fix the prepared Dendrobium seedlings at the base in the tree notch with bamboo nails or ropes, and then smear cow dung slurry (made by mixing cow dung and mud evenly) on their roots and the surrounding bark grooves. To prevent wind shaking and rain washing, generally bamboo nails should be used to nail them firmly or bamboo strips and other ropes should be used to tie 2 loops, to fix the Dendrobium fibrous roots and plants on the trunk or tree forks. When planting on trees, proceed from top to bottom.
4. Field management
After planting Dendrobium nobile, moist air conditions should be maintained, and watering should be appropriate, but overwatering must be strictly prevented, and water accumulation causing root rot must be avoided. No fertilization is needed when planting Dendrobium; topdressing begins in the second year after planting, 1~2 times per year. The first is sprout-promoting fertilizer, applied around the Spring Equinox to Qingming; the second is warmth-preserving fertilizer, applied around the Start of Winter. Use cake meal, bean dregs, cow dung, pig dung, fertile soil plus phosphate fertilizer and a small amount of nitrogen fertilizer, mix evenly, and then spread a thin layer around the roots. Because the root absorption function of Dendrobium is relatively poor, in order to promote its growth, during its growth period, every 1~2 months, foliar fertilization is often carried out with 2% superphosphate or 1% potassium sulfate. Regardless of the cultivation method used for Dendrobium, the time for applying fertilizer and water should be after the morning dew has dried, and it is strictly forbidden to apply under the high temperature of the blazing sun, otherwise it will seriously affect the normal growth of Dendrobium. After planting, Dendrobium is weeded 2 times per year, the first from mid-March to early April, and the second in November. In the high-temperature summer season, weeding is not suitable, so as not to affect the normal growth of Dendrobium. Before sprouting each spring or when harvesting Dendrobium, some old branches and dead branches, as well as overly dense stems and branches, should be cut off to promote new bud growth. After 5 years of planting Dendrobium, the plants sprout many shoots, old roots die, the substrate rots, and pathogens infect, causing poor plant growth; therefore, according to growth conditions, the clumps should be turned over, dead and decayed old roots removed, and division carried out for separate cultivation, to promote plant growth and increase yield and income.
5. Pest and disease control
The main diseases that usually appear during the growth and development of Dendrobium nobile are: ① Black spot disease. This disease often occurs from March to May. Use 1:1:150 Bordeaux mixture or 1000-fold Duoling solution to prevent and control its development. ② Sooty mold. March to May is the main onset period of this disease. Use 50% carbendazim 1000-fold solution or 40% dimethoate emulsion 1500-fold solution spray 1~2 times for control. ③ Anthracnose. January to May is the main onset period of this disease. Use 50% carbendazim 1000-fold solution or 50% thiophanate-methyl 1000-fold solution spray to prevent and control infection of new plants by this disease. The main pests currently found are: ① Dendrobium scale insect. Late May is the peak hatching period for this pest; spraying with 40% dimethoate emulsifiable concentrate 1000-fold solution or 1~3 degree lime sulfur mixture gives better control effect. For those that have already formed shields but are few in number, control can be carried out by cutting off old branches and leaves, burning them in a concentrated manner, or crushing them to death. ② Snails. Mix bran with trichlorfon and scatter it in places where the pests frequently move for poison bait trapping; spray trichlorfon, deltamethrin and other pesticides on the cultivation bed and surrounding environment, and quicklime can also be scattered.
6. Harvesting and primary processing
After 2~3 years of cultivation, harvesting can be done throughout the year, but it is best to harvest before the plants sprout from the Start of Winter to Qingming. When harvesting, use scissors or a sickle to cut the old plants from the stem base, taking care to harvest old ones and leave young ones, so that the remaining young plants continue to grow, achieving the goal of planting once and benefiting for many years. Fresh Dendrobium is harvested without removing leaves and fibrous roots and is directly used for medicinal purposes. Or remove fibrous roots and branches and leaves, and store in wet sand for later use. The traditional processing methods for dried Dendrobium are the water blanching method and the hot stir-frying method. ① Water blanching method. Remove leaves and fibrous roots from fresh Dendrobium, soak in water for several days until the leaf sheath membrane rots, then use a brush to scrub off the leaf sheath membrane on the stems or use rice husks to rub off the membrane. After draining the water, roast and dry; after drying, bind with dry rice straw and cover with a bamboo mat to keep airtight. The roasting heat should not be too strong and should be even. When roasted to 70~80% dry, rub and knead once more and dry again, take out and spray a little boiling water, then stack in order, cover well with a straw mat, make the color turn golden yellow, and then roast until completely dry. ② Hot stir-frying method. Place the fresh Dendrobium cleaned as above in a pot containing heated river sand, press the Dendrobium down with the hot sand, frequently turn it up and down, stir-fry until there is a slight crackling sound and the leaf sheaths are dry, cracked and curled up, then immediately take it out and place it on a wooden washboard and rub and knead repeatedly to remove all remaining leaf sheaths, wash away the sand and mud with water, dry in the hot sun, and after night dew, rub and knead repeatedly again the next day, repeating this 2~3 times, so that its color is golden yellow, the texture is compact, and it is dry.