An Analysis of the Relationship Between Orchid Growth and the Air Environment

Of the many elements in the air, the periodic table of chemical elements contains eleven gaseous elements, most of which are related to plant growth. It should be particularly noted thatorchidsare advanced mycorrhizal plants, and their air permeability requirements are much higher than those of other plants. For example, hydrogen and oxygen in water molecules mainly form carbohydrates.Orchidsduring photosynthesis mainly absorb nitrogen (N2) from the air along with the carbon dioxide (CO2) produced from hydrogen oxides and water. Mycorrhizal proliferation and nitrogen fixation also require large amounts of air. In particular, carbon dioxide must be decomposed and absorbed, and the digested nutrients must be recombined by various amino acids intoorchidcells of all types needed by each part, and oxygen (O2) from the air must participate in all of this. Hence the saying that carbon dioxide is breathed in and oxygen is breathed out. The main cause of orchid root rot is poor air permeability. This is the fundamental difference between orchids and other flowers. The better the ventilation conditions, the more favorable it is for orchid growth. Ventilation and air permeability were regarded by the ancients as the first essential principle of growing orchids. Through practice and long-term observation, we have learned that in the potcultivationone should achieve "six sides and one point all ventilated," which is greatly beneficial for growing orchids well. The so-called "six sides" means that the position where the orchid pot is placed can be ventilated and aired from above, below, left, right, front and back; the pot stand must have gaps and must not block the bottom hole of the pot. "One point ventilated" means that the growing medium in the orchid pot has good air permeability and can exchange with the outside air, so the material used should have a certain granularity, should not become waterlogged, and the pot should be ventilated and aired. Therefore, some people advocate using clay pots to grow orchids. Using pots with holes in the decoration or pots with wall holes can make ventilation and air permeability even better. As long as the orchid pots are placed properly, the air orchids need can be self-regulated. Air expands with heat and contracts with cold. On windless days, the airflow around the orchid stand continuously moves up and down, and convection can occur between indoors and outdoors and between the inside and outside of the shed. The warm, humid airflow below continuously rises, while the cool air above automatically descends to replenish it. The air in the gaps of the potting medium inside the pot also naturally regulates airflow through expansion and contraction, and in this cycle the air supply on windless days can be maintained. If the weather is good, the shed and windows should be opened to increase air convection. Another characteristic of air is that it regulates temperature and holds moisture, so for orchid growers with orchid sheds, different requirements should apply to low and high temperatures in winter and summer. For example, when the temperature inside the orchid shed is above 40 degrees in summer, large oscillating electric fans should be used for cooling. Each fan can handle the ventilation, air permeability and cooling for about 15m2. A gentle breeze brushing the surface is best. The emerald-green orchid leaves are moved by the flowing air and sway gently. In this situation, if humidifying misting is added as well, orchids can be nourished by fresh air. Air is especially important to orchids, but the other side of air should also be recognized. Air naturally regulates temperature and humidity, and sometimes it can harm orchids. Dry winds in spring and autumn have a great impact on orchidflowers'growth. In spring, strong winds carry away moisture, and grass buds cannot emerge on time; in autumn, dry winds prevent immature grass from growing fully, so shading must be provided. "Good air permeability" refers to conditions without wind, and does not apply when dry wind causes harm. Generally speaking, air quality in the countryside is relatively good, while in cities it is somewhat worse. Even with good ventilation and air permeability, air quality must also be considered. For example, urban vehicles, factories and so on emit large amounts of toxic gases containing arsenic, fluorine and sulfur, and coal gas may also leak. When these gases are absorbed by the stomata of flowers during photosynthesis, they can poison orchids, or cause orchids to close their stomata to resist the harm and stop photosynthesis. If these problems cannot be solved, orchid growth will certainly be affected. Isolation measures, dedicated shed frames, sealed balconies and other methods can avoid the harm. Monsoon winds can also polluteorchid grass, especially in the windy and sandy weather of the north and the dry windy weather of the south in spring and autumn, when dust flies everywhere. If orchid pots are placed in the open air, this is very unfavorable, and dust and sand pollution should be avoided to prevent a drop in the environmental temperature of the orchid site. In coastal provinces and cities such as Jiangsu, Zhejiang, Shanghai and Anhui,when growing orchids, attention must be paid to preventing typhoon strikes, avoiding orchid pots placed on balconies being blown down and damaged, and preventing tall grass from being broken by wind. Typhoon prevention is something that must be noted in summer forbalconyorchid growing. In short, the air requirements for orchids are "ventilation without wind, gentle breeze blowing, strong wind should be guarded against, and above all dirt must be prevented." Guan Wenchang, Zhu Hexing