Environmental and physiological factors of cultivated Orchid

1. Air pollution orchid clean, if air pollution will cause poor growth, leaf surface corrosion, discoloration, and even necrosis, as well as flowers early withering, sepals yellowing and so on. Serious cases can also lead to the death of the whole plant.

2. Excessive humidity is not only susceptible to disease, but also causes plant softness, dryness and poor growth.

3. Orchids should not be suddenly exposed to strong light. In addition, the light is too strong and too weak, and the light time is too long and too short will cause poor growth. For example, too much light can turn leaves yellow, mainly because chlorophyll is destroyed faster than synthesis under strong light, and extreme light and sudden exposure can scorch the leaves. For example, vanilla sunburn is caused by direct exposure to the sun, causing chocolate spots and cracks on the leaves, and sunburn can also lead to bacterial infection. If the light is not enough, the leaves will be dark green, and the extreme deficiency will turn yellow, causing poor growth.

4. If the temperature is too high, especially at night, it can make plants deciduous, weak, poor growth, and even cause death. If the temperature is on the low side, it will cause too much chlorophyll, as well as poor growth, and serious ones will cause death. In addition, some orchids need periodic changes in temperature, including seasonal changes and diurnal changes, and will not blossom if they do not meet this condition.

5. Too much or too thick fertilizer will make the salt concentration on the soil matrix too high, causing a large withered area or leaf tip to dry up, commonly known as "burning to death".

6. Minerals, like other plants, the lack of certain elements can also make orchids morbid. For example, boron deficiency can cause necrosis of the apical leaves, blackening and death of the southern meristem, short roots and short plants. Calcium deficiency will make the newly growing organs deform and not grow, the leaves are yellowed and curled, the leaf tips are dry and the roots are underdeveloped. Chlorine deficiency will wither the leaf tips and make the leaves bronze. Lack of copper will wither the tip of the seedling and fade the leaves. Iron deficiency can lead to yellowing, especially in newly growing organs, turning yellowish or nearly white, especially between leaf veins. Magnesium deficiency will make the old leaves yellow, but the veins of the leaves are still green, the whole leaves are fragile and easy to fall off, and the plants do not grow well. Manganese deficiency will make the leaves with mottled yellowing, leaf veins dark green, yellow or white between veins, and stems yellow and white. Lack of molybdenum will make the leaves do not unfold and appear yellowish yellowing. Nitrogen deficiency will cause plants to yellowing and grow poorly. Phosphorus deficiency will make the plant short, the leaves dark green and purple, and anthocyanins on the veins. Potassium deficiency can make the leaf margin yellowing or necrotic, the leaf surface shrinking between the leaf veins, and the plant is short. Lack of sulfur will make the stem thin, the leaves light green to yellow, and the roots grow slowly. Zinc deficiency will make the leaves yellowing or necrotic, the upper leaves turn white, the old leaves have whitish yellowing stripes, and the plants become clumpy.

7. Other comprehensive factors, including air pollution, temperature and humidity discomfort, fertilizer nutrient imbalance, and drug damage, self-physiological diseases (such as ethylene production), can cause bud withering and early falling, flower defects and discoloration. Premature aging (mainly caused by ethylene) and so on. (Chen Xinqi, Ji Zhanhe)