The influence of the temperature of national orchid

The root system and stem and leaf growth of Cymbidium are greatly affected by the temperature in the atmosphere and medium, and the most suitable temperature for the growth of Cymbidium is 18-28 degrees. Low temperature will affect the functions of photosynthesis, respiration, evapotranspiration, transportation and storage of assimilation substances. Beyond the critical point of orchid root growth, root growth will stop because of high temperature. Root elongation, root water absorption capacity stop, the physiological function of the plant decline, over time, the life of the orchid plant will be shortened. High temperature will damage the root tissue and secrete toxic substance ammonia to poison the root cells, resulting in the death of root cells.

At high temperature, the decomposition rate of organic matter in the medium is accelerated, and the medium is in a strong redox state, resulting in a large number of carbon oxide, soluble divalent iron, organic acid, methane, ethylene and other harmful substances will directly poison the root cells. the root system and the base of the stem will form reddish brown and thick black disease because of the harm of these harmful substances, and the root tissue will rot and die in serious cases. When the temperature is too much beyond the critical point of growth, the high temperature increases the leaf evapotranspiration, the water in the plant evaporates rapidly from the leaf stomata, the root system breathes rapidly, and the orchid root must absorb a large amount of water from the root system. in order to maintain the turgor of the national orchid cells and regulate the temperature in the leaves and maintain its upright.

If in the case of high temperature and poor ventilation of the medium, Guolan leaves evaporate and lose a large amount of water in the body, and the water absorption capacity of the root system is affected by temperature. Guolan plant will temporarily wither due to lack of moisture, which will cause the orchid plant to wither for a long time, and then become water withering and die. In this way, not only the stem and leaf growth and root growth will be affected, but also the orchid plant will be seriously injured, which will affect the growth of new buds and even cause the orchid plant death. Therefore, how to use Yin, exhaust, humidification to cool down is still a necessary means.

When the temperature was below the critical point of national orchid growth, the cell membrane and metabolic enzymes of national orchid cells could not stand low temperature and were seriously damaged, and the activity of root system decreased. At low temperature, the respiration of roots will slow down or even stop. The heat energy needed to absorb nutrients can not be fully obtained because of low temperature accompanied by weak light. In addition, the root activity can not play a role, the absorption and transport of water and nutrients will be hindered. The amount of photosynthate and storage decreased, and the rate of corm hypertrophy decreased, which was only enough to maintain its own life, and there were no extra nutrients for root growth. It caused the growth of national orchid plants to stop or be dormant. The new buds are also getting smaller and smaller due to the limitation of temperature, and the number of leaves is also less than that of the original plants.

Moreover, the activity of microorganisms in the medium at low temperature is affected by temperature, which can not decompose organic matter normally, and when decomposing organic matter, it secretes IAA and GA, which promote root elongation, growth hormone, amino acid, ribose and other substances beneficial to root growth, slow down the ability of absorption and transport of blue root, and reduce the amount of nutrient elements needed for leaf growth and development. As a result, Langen lost his original function and died of aging and fester.

In the hot summer season, the daily sunshine time is often as long as 12 to 15 hours. Especially in the 2 hours from noon to afternoon, the PC transparent plate in the orchid room absorbs the radiation energy irradiated directly from the sun, and the accumulated temperature is often more than 30 degrees Celsius. The hot air in the orchid room accumulates, and the temperature rises sharply, and exceeds the critical point for the growth of the orchid. If the cultivation managers do not take cooling measures, the root growth of the orchid will be damaged by high temperature.

In general, during the period of high temperature in summer, cultivation managers can install shading net, increase orchid indoor ventilation equipment, set up flowing water under the orchid shed, spray water above the roof or use a variety of mechanical, physical and other humidifying and cooling equipment to cooperate with each other, the cooling effect can be achieved, so that the national orchid can grow in a suitable temperature environment and avoid the influence of high temperature. In this way, there is a good environment for the root growth of the national orchid, and the plants with better quality and yield can be cultivated.

When the winter temperature is below the critical point of the growth of the national orchid, the tissues of the national orchid will enter the dormant period to survive the cold season. During dormancy, the national orchid will consume the nutrients accumulated during its growth in order to maintain its own life. When the temperature is below the lowest point for the growth of the national orchid plant, the plant cannot stand the cold temperature, which does great harm to the growth and development of the national orchid plant and its ability to germinate the next generation.

Generally speaking, for the national orchid plants growing at cold temperatures in winter, due to the influence of low temperature, the orchid plants themselves will go into dormancy and consume the heat and nutrients accumulated in the plants, and when the suitable temperature for growth appears, the orchid plants themselves can perform various functions.

During this period of dormancy consumption, the plant has consumed most of the nutrients, so that the new orchid plant can not get more nutrients from the mother plant, so that it becomes smaller for cell division. In addition, when the growth condition of the plant itself is poor, there is no extra nutrients for root row division, so the root coefficient and root growth will be seriously limited.

During the low temperature period in winter, the cultivation manager should close the doors and windows of the orchid room, leave only a small air intake below the orchid room, and change air at about 10:00 in the morning when the outdoor temperature of the orchid room is equal to that of the orchid room, so that fresh air can enter the orchid room for gas exchange. When the temperature drops in the afternoon, in order to prevent the loss of heat accumulated by the sun during the day, the cultivation manager should close the doors and windows and prevent the cold wind from directly entering the orchid room and affecting the growth of orchid plants.

When the night temperature is below the critical point for the growth of the national orchid, the grower should set up heating equipment, such as cross-heating of hot air and hot water, to increase the temperature of the orchid room and maintain the temperature suitable for growth, so as to help the national orchid plant through the period of oligo-cold dormancy. Make the national orchid grow in the most suitable warm and humid environment. In this way, the national orchid growth can maintain and meet the growth needs, and avoid the limitation of the growth amount and growth potential caused by the lack of accumulated temperature.