Influence of Environmental conditions on Chinese Orchid

The growth and development of Chinese orchids is not only determined by the genetic factors of the mother plant, but also affected by environmental conditions. the quality of national orchid cultivation is also shown in how to properly coordinate the six environmental factors needed for the growth and development of national orchid to achieve the purpose of cultivation, which can not be separated in isolation, but under specific circumstances, there will always be one of the factors that play a leading role.

(1) Light

Light is a necessary condition for plant survival, and it is an energy source for plants to carry out photosynthesis, produce nutrients and improve their own growth. The whole process of growth and development of orchids is mainly affected by light wave, light intensity and light time.

A. different wavelengths of light have different effects on orchids in different growth periods, and there are mainly the following kinds of light:

A. The red and orange light at the wavelength of 600-700nm is the light area with the strongest absorption of chlorophyll and the strongest photosynthesis. In particular, red light can promote the growth of orchids, but only red light will make national orchids grow in vain, which is not suitable for orchids with line skills and broad leaves.

B. The blue-purple light at the wavelength of 510-610nm is the light area with strong absorption of chlorophyll and lutein. Among them, blue light is the main source of pigment, and can also promote the absorption of phosphate fertilizer. Thickening of stems and leaves, accelerating plant development, regulating stomatal opening and so on. Is indispensable. Purple light mainly forms anthocyanins and inhibits the elongation of branches and leaves.

B. effect of light intensity on national orchid

In the four seasons of the year, the illuminance of sunny noon open field in summer is about 100000 LUX, and that of sunny noon open field in winter is about 25000 LUX. Cloudy and rainy days in this area account for about 20% of sunny days. Orchid leaves can have photosynthetic effect when the illuminance is 3000~5000LUX. According to the test, it is known that the illuminance of the orchid is about 5000LUX and that of the line is about 4000LUX. Narrow leaf national orchid needs high luminosity, which can reach 10 000 LUX. Therefore, under normal circumstances, photosynthesis will not be hindered by insufficient light intensity, but the light has a lot of important relationship to the flowering period and color of the national orchid: too much light in the flowering period will shorten the flowering period, and avoiding excessive light can prolong the flowering period appropriately. Anthocyanin is the main pigment of orchid, which is produced in strong light, but not easily in weak scattered light, so the flower color of the same variety of national orchid will change greatly under different light intensity, that is, light intensity can inhibit or promote the formation of anthocyanin. In addition, too strong light is not conducive to the growth and development of orchid rhizome (dragon root). At present, some orchid friends use ordinary fluorescent lamps as artificial light sources. According to the test: the wavelength of general fluorescent lamp is the yellow and green light of 500nm. And in a 40 watt fluorescent lamp 20 cm only measured 400LUX, the luminosity is not enough, and the lamp heat is dangerous to the orchid leaves. Use artificial light source, at least more than 60cm from the leaf surface to prevent damage to the leaf. A 28-watt energy-saving lamp 2000LUX, a 35-watt energy-saving lamp can reach 3000LUX. You only need to add a lampshade with high reflectivity to find the ideal light source of 4000-5000LUX.

In addition, every 2 square meters, 40W pure red and pure blue fluorescent lamps can be used as a group as light wave adjustment. When the new seedlings grow to 78 minutes of maturity, you can add a purple lamp.

C. effect of light time on national orchid

We know that under effective light, the national orchid converts carbon dioxide and water into carbohydrates under photosynthesis for its growth and reproduction. In order to better cultivate the national orchid and artificially prolong the lighting time, it has been proved to be a good way in the practice of the majority of orchid friends. But the national orchid can be divided into long-day nature and short-term nature. The sunshine time of short-day Cymbidium is less than 12 hours a day, which is beneficial to its flower bud differentiation, such as Chunlan, Hanlan and Orchid. Long-day national orchid sunshine time in 12 hours a day to form flower buds, such as Siji orchid. However, if the sunshine time is extended endlessly, it is disadvantageous to the growth of national orchid. Because the plant must go through a dark period before its cells can fully grow, if the end of its limited dormancy period will lead to incomplete cell differentiation, orchid seedlings can not grow healthily.

(2) temperature

The effect of temperature on the growth and development of national orchid can be divided into air temperature and soil temperature (basin temperature), and their effects on national orchid are equivalent.

A. the influence of temperature on national orchid

The most suitable temperature for the whole life activity of national orchid is about 18-25 ℃, but the lowest temperature of different varieties of national orchid is different. The winter night temperature of Cymbidium is about 5 ℃ and can withstand temperatures below 0 ℃. The age-bearing orchid is about 10 ℃, and if it is less than 5 ℃, there is a risk of frostbite. Cymbidium and cold orchid are between the above two categories. The maximum temperature that Guolan can withstand is about 50 ℃. There has been an orchid experiment in our city to put dozens of pots of orchids in a high temperature room of about 50 ℃ during the day and 40 ℃ at night for more than 20 days, in an attempt to treat the virus disease of the orchid. Although the orchids are finally scorched, there are still a few wisps of fragrance, which shows the degree of heat resistance of the orchids. In a certain range, the higher the temperature, the more exuberant the photosynthesis. When 10 ℃ was added between 10 ℃ and 35 ℃, the respiration increased by 2-3 times. In general, high temperature promotes vegetative growth, while low temperature is conducive to reproductive growth. For the same kind of orchid, the leaf bud is more tolerant to low temperature than the flower bud, and the root is more tolerant to the low temperature than the stem. Properly increasing the temperature difference between day and night in the process of cultivation is beneficial to the bulb size, budding and budding of the orchid.

B. influence of soil temperature (basin temperature) on national orchid

Pot temperature has a great effect on seed germination, root development and seedling growth. Only when there is enough heat in the basin can the root system better absorb the water and nutrients in the soil. When the pot temperature is 3-6 ℃, the survival rate of seedlings is the highest. Therefore, the increase of basin temperature in winter is more conducive to the growth of orchid than the increase of air temperature.

(3) Water

Water is an important part of plants, accounting for about 70% of the fresh weight of the national orchid. It is an indispensable factor in the physiological activities of the national orchid. If there is no water, the physiological activities of the orchid will stop and the orchid will die. The main moisture affecting the growth and development of Cymbidium is soil moisture and air humidity.

A. effect of soil moisture on national orchid

When watering, the water is first sucked into the inside of the particle by the plant material in the basin, which is called absorbing water, which cannot be used by plants and continues watering. The water is absorbed in the surface and space of the particle, which is called capillary water, and it can be used by plants. After watering, the free flow water in the soil is called gravity water, which can flow away quickly when the drainage is good. After the gravity water in the soil is discharged, the amount of water contained in the soil is called inter-basin water holding capacity. In the cultivation of national orchid, it is appropriate to keep the plant humidity at 60% of the water holding capacity in the basin. When it is more than 80%, the space in the plant material is reduced, the respiration of the orchid root is blocked, and the growth stops, and it is easy to rot. When the soil moisture is too dry, the concentration of the soil solution is too high, and the root cells die by reverse osmosis.

In cultivation, soil moisture is generally controlled by watering times. It for different varieties, different leaf quality, different plants, different growth periods, different temperature. Has a different impact. For example, fine-leaf orchids have relatively less water requirements. On the other hand, broad-leaved orchids should have more water; if the leaves are thick and wrinkled, they can be watered less and increase the air humidity; those with thin and flat leaves should be given more water and should be placed in a cool place; if they are strong and have more roots, they can absorb more water and can give more water: those with weak and small roots are not easy to grow roots if they are too wet, and during the new bud growth period, more water should be watered for vigorous physiological activities; during the flowering period of adult plants, they should be watered less to promote flower bud differentiation. More water should be watered in the high temperature period to compensate for water evaporation and less water in the low temperature period.

B. the influence of air humidity on national orchid

Although the national orchid belongs to the terrestrial orchid plant, its thick and fat fleshy root makes it still have some properties of aerial orchid. In the process of cultivation, high air humidity is an important factor for successful cultivation, especially the coarse-skinned national orchid which is more popular in recent years. High humid air can not only fully express the new generation of art, but also improve the germination rate. It is observed that about 80% humidity is the best for the growth of Guolan. If the air humidity is too high, it is easy to cause poor resistance of seedlings and weak seedlings and be infected with diseases and insect pests. In particular, greenhouse cultivation should pay more attention to timely ventilation and control air humidity.

(4) soil (plant material)

Among the factors that determine the success or failure of national orchid cultivation, plant material is the primary factor. Only by fully understanding the different properties of plant material can we improve and make good use of plant material and plant orchids well.

The traditional cultivation of national orchid plant materials are mainly used; field soil, cow dung soil, baked soil, soaking mud, humus soil, pond mud, culture …... And so on all kinds of soil. They all have some common problems: complex comprehensive components, difficult to control nutrient elements, not easy to sterilize, and difficult to control the balance of water and air in the soil.... no, no, no. We know that when the plant material is well ventilated, the microbial activity in the plant material is strong, which can transform the organic matter in the plant material into an available substance for plant absorption. At the same time, sufficient air in the plant material can promote root respiration and absorb more nutrients from the plant material, and the fleshy root of Guolan has higher requirements for air and water. Only by controlling the balance of water and air in the plant material, can we meet the national orchid's demand for air and water at the same time, and grow orchids well. In recent years. Through the continuous efforts of the majority of national orchid lovers, a variety of soilless cultivation methods have been widely used in the orchid world. The varieties of new plant materials emerge in endlessly. From serpentine sawdust, water grass, broken tiles, red brick grains, sea pumice, weathered rock granules, volcanic rocks to kiln soil particles, burning pond mud, Puli stone, Japanese orchid stone and so on. There are all kinds of Chinese and foreign products, all of which focus on light weight, simple composition, convenient pest control and sterilization, and convenient control of nutrient element content. Sanitary and clean, good water use and ventilation. To facilitate the control of water and gas balance as the starting point, it is observed that the use of fine plant materials (such as soybeans) around the orchid head 2cm is of great benefit to the national orchid root.

In short, it is neither loose nor tight, it can not only ventilate and permeate water, but also store water and preserve fertilizer. The plant material with coordinated conditions of water, fertilizer, gas and heat is the ideal substrate for the cultivation of national orchid.

(5) nutrient elements

In the process of growth and development, the national orchid absorbs carbon from carbon dioxide in the air and hydrogen and oxygen from water. These three elements form the basic structural carbohydrates of plants, accounting for about 93% of plant dry weight. In addition, nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, boron, manganese, copper, zinc, barium and other minerals are absorbed from plant materials. The contents and requirements of the first six elements are more in the orchid plant. Called a large number of elements. The latter several kinds of content are less, called trace elements, trace elements need to be used less, but have a great impact on the physiological activities and quality indicators of Guolan, which is both indispensable and not too much.

A. Nitrogen (N): it is the main component of synthesizing protein and chlorophyll in the national orchid. The application of nitrogen fertilizer can promote the growth of leaves and buds and thicken the color of leaves, but too much nitrogen fertilizer will cause overgrowth of orchid leaves, weakening disease resistance, delayed flowering, small flowers and even flowers, especially for Yilan. When the nitrogen fertilizer is insufficient, the cell wall is thick, the growth rate is slow, the leaf color is light green, and the whole forest is underdeveloped. Nitrogen fertilizer is usually applied at the early stage of orchid plant growth to promote leaf growth. It also makes the roots grow. However, when nitrogen fertilizer is applied in the later stage of growth, the leaves grow but the roots do not grow, so they should be applied cautiously in the bud stage.

B. phosphorus (P): it is an important component of nucleus and protoplasm. Phosphorus is needed for cell division, chlorophyll formation and corm maturity of the orchid plant. It can promote the differentiation and formation of leaf bud and flower bud, promote early flowering, enhance the development ability of root system, and enhance the resistance of national orchid to adverse environment and diseases and insect pests. In the vegetative growth period of seedlings, as long as an appropriate amount of phosphate fertilizer is applied, more phosphate fertilizer is required after flower bud differentiation. If there is a lack of phosphorus, the growth of Lanlin rhizome is hindered. As a result, the orchid plant is thin and weak, dark green, petiole turns purple, leaves fall off, and disease resistance is weakened.

In addition, phosphorus deficiency also affected the nitrogen uptake of orchid plants.

C. potassium (K): its function is to dissolve nutrients, expand cells, and make nutrients permeate into various tissues. When potassium is sufficient, it promotes the tenacity of orchid plants, makes it not easy to lodge, and promotes the formation of chlorophyll and photosynthesis. It can also enhance the drought resistance, cold resistance and disease resistance of the orchid plant, and the flower color can also be bright and lasting. When the potassium content is insufficient, yellowish-brown spots appear between the edges of the leaves and the veins of the leaves. The tissue of the corm is weak and easy to be infected with diseases, which can seriously hinder the growth of the orchid plant and stop. If excessive potassium fertilizer is applied, the plant will be low, the internodes will be shortened, the leaves will change color and shrink, and even the orchid plant will wither and die. That's what's wrong with what's commonly known as Insigu.

D. Calcium (Ca): it is one of the main components of the nucleus. Calcium is needed for root tip and bud growth. The effect of calcium is opposite to that of potassium. It unites nutrients to facilitate the uptake of various tissues. Calcium and potassium have antagonistic effect, so the content of calcium and potassium must be in proportion before the plant can grow normally.

E. magnesium (Mg): it is an essential component of chlorophyll and its function is to regulate photosynthesis.

F. Sulfur (S): it is not only the component of protein and enzyme, but also the component molecule of leaf wax of orchid plant.

G . Iron, manganese, copper, zinc and other elements are redox contact agents in plants, and their function is to promote the formation of chlorophyll.

H. The functions of chlorine, aluminum, boron and other elements are similar to those of potassium. If orchid plants lack these trace elements, they will lead to bud and root growth point death, flower buds not opening, catheter collapse and softness, tissue necrosis or blackening.

(6) Air

Fresh air is an important condition for photosynthesis and respiration of plants. In the natural environment, the air contains 21% oxygen and 0.03% carbon dioxide, and the composition of various gases maintains a certain proportion, while the composition of various gases in the greenhouse changes greatly. if it is not ventilated in time, it will increase harmful gases and reduce useful gases. and affect the normal growth and development of orchids. And the flowing air can not only continuously send carbon dioxide to the orchid leaves, maintain the balance of the concentration of carbon dioxide next to the leaves, and breathe in the leaves, but also be of great help in regulating the air humidity balance in a certain environment.

In addition, salty sea breeze and exhaust gases from factories, such as chlorine, sulfur dioxide, fluorine, volatile gas of organic solvents, and other harmful gases harmful to orchid plants should be paid attention to in the cultivation of national orchid.

(Wu Pinglang, Orchid Association of Xiamen, Fujian)