The influence of PH value in cultivation medium

The most suitable PH value for the growth of national orchid root system is about 5.5-6.5. The PH value higher or lower than its critical point in the medium will hinder root growth and indirectly affect the growth and development of stems and leaves. At present, the medium materials used in the cultivation of national orchid are mostly made from a single material or a mixture of several different kinds of materials. Organic or inorganic materials are mixed with each other, and each medium material contains different PH values, which have different effects on the root system and future growth of Orchid. The PH value in the medium also has a great difference on the dissolution of various nutrient elements needed for the absorption of national orchid, the reproduction of beneficial and harmful microorganisms, and the absorption and metabolism of national orchid.

When the PH value is below 5, the availability of trace elements such as copper, manganese and iron in the medium increases, which is easy to poison the roots; nitrogen, phosphorus, potassium, calcium and magnesium become insoluble, and the main elements absorbed by the roots are insufficient. The growth of the orchid will show the hunger phenomenon of leaf yellowing. And in the acidic medium, phosphorus is easy to combine with iron to reduce its effectiveness and limit the development of roots; if the PH value is too low, the activity of nitrifying bacteria in the medium decreases, and the nitrification of ammonia nitrogen is inhibited. Under the insufficient light environment, the photosynthesis of Guolan leaves decreases, and the assimilation efficiency of ammonium nitrogen decreases, resulting in ammonium poisoning. In acidic environment, soil-borne bacteria in plant materials such as root rot, blight and Rhizoctonia solani are the most suitable for growth and reproduction, endanger the root system and accelerate the decay and death of orchid root.

If the PH value is higher than 8, it belongs to alkaline, the availability of trace elements such as copper, zinc, manganese and iron decreases, and the roots of Guolan can not be absorbed, resulting in growth disorders and easy root death. In alkaline environment, ammonia nitrogen is easy to form ammonia volatilization, which reduces the supply and absorption of nitrogen fertilizer, the rate of return on fertilizer investment is low, forms waste, and will inhibit the growth of root system.

In the environment with high PH value, phosphorus is easy to combine with calcium and reduce the demand for phosphate fertilizer in roots, so the development of roots will be seriously limited by the lack of phosphorus. If national orchid roots and stems and leaves want to grow or proliferate normally, they need to absorb a certain proportion of nutrient elements, and the amount of element absorption will directly affect the growth of national orchid roots and stems and leaves. In addition to the different growth periods and growth conditions of the national orchid, or the lack of certain nutrient elements, the growers supply their deficiency by adding ways, and supply an appropriate amount of organic matter or plant growth promoters in a timely manner to improve the buffer capacity in the medium, so that the medium is not easy to acidify, improve fertilizer use efficiency, reduce fertilizer use times, and promote the development of national orchid root system. The function of root system is improved, the width of stems and leaves, the absorption and storage of nutrients are improved, and the differentiation and growth of lateral buds will not be restricted.

When the cultivation manager was in the cultivation management, it was found that the root system of the orchid plant was short, thick and brown rotten. When the leaf tip is scorched and other phenomena, the PH value of the medium may be somewhat acidic, resulting in a large number of root rot fungi, Phytophthora, Rhizoctonia solanacearum, excessive accumulation of manganese, large amount of dissolution, phenolic compounds and hydrogen sulfide and other harmful or toxic substances will directly harm the root system.

The application of calcium carbonate in the medium can adjust the PH value and slow down the reproductive life of pathogenic bacteria. When there is a lot of white powdery crystals on the surface of the orchid basin, it can be clearly seen with the naked eye that it may be formed by the application of too much salt fertilizer by cultivation managers. Too much salt will seriously inhibit the growth of lateral buds, cause bud point necrosis and affect the yield.

Therefore, whether the PH value is moderate or not will not only affect the root growth and development, nutrient absorption capacity, but also affect the stem and leaf growth and lateral bud germination ability. During the cultivation and management, the growers should pay attention to the change of the pH value of the medium anytime and anywhere, try to keep the pH value of the medium within the range suitable for the growth of Langen, and avoid excessive shower leading to acidification. Do not wait until the medium has been acidified seriously, the root system necrosis everywhere to find a solution, that has caused great damage to the national orchid plant, want to cultivate exuberant roots in a short period of time, the roots are thick and white It may take a long time for orchid plants with luxuriant stems and leaves and high germination rate to make progress from generation to generation. National orchid cultivation managers need to pay more attention to the management of PH value before they can cultivate national orchid plants with healthy and vigorous root growth.