Prevention and Control of non-communicable Diseases in Cymbidium

The so-called non-communicable disease is actually a kind of physiological disease that has not been invaded by biology. It includes the ecological environment conditions which are not suitable for the normal life of Magnolia. If the salt content in soil and water is high, and the concentration of soluble salt is higher than the degree that the orchid can bear, salt damage will occur, resulting in a series of factors, such as imbalance of water supply, lack of nutrient elements, inappropriate temperature and light or improper cultivation and management, and damage caused by other harmful poisons, etc., all these morbid diseases that affect the normal growth and development of Magnolia are collectively referred to as non-infectious diseases.

1. Daily fever

Also known as sunburn. It is a physiological disease, which mostly occurs in summer and autumn. Due to the high temperature of the habitat, the strong light shines directly on the leaf surface. The leaves of light ones changed from green to yellow, while those of heavy ones dried up and died.

Disease regularity: indistinct yellowing dry plaques appeared on the edge of the susceptible leaves. The disease seriously affects the ornamental value and normal growth and development of the plant, thus reducing the quality of the plant.

Prevention and control methods: (1) when planting Cymbidium in greenhouse, it should be shaded properly from June to September. When the indoor temperature exceeds 30 ℃, it is necessary to strengthen ventilation or spray water to cool down. (2) the family planting magnolia should avoid bright light and high temperature, and should be placed in a cool place. (3) once sunburn occurs, the injured leaves should be cut off to prevent other diseases.

Summer and autumn high temperature, strong light, should pay attention to avoid light, flower cellar can add sunshade net, bamboo curtain, Wei curtain to reduce light intensity, create a scattered light environment, and pay attention to ventilation and cooling.

2. Chlorosis

Also known as chlorosis. The etiolation of Cymbidium is caused by rapid lack of water and iron.

The law of the disease: the damaged leaves showed milky white patches, or all turned yellowish white, and in severe cases wilted, wrinkled and withered. Orchid yellowing disease has a variety of manifestations: all the leaves turn yellow, which is often a symptom of sunburn disease. Leaves start yellowing from the tip, often because the culture soil is not completely mature, or too much fertilizer and water, resulting in root burning. The yellowing of individual leaves is likely to be the result of fire, cold wind or acid-alkali erosion. Sometimes the whole leaves of Cymbidium turn yellow, mostly because of nutritional deficiency. Another kind of leaf yellowing is caused by lack of light.

Prevention method: put the magnolia in the shade shed, cool and ventilated place in summer, and illuminate the magnolia with a shade of 50% to prevent the occurrence of sunburn. Orchids must be cultivated with mature, loose, slightly acidic rotten leaf soil. When the temperature exceeds 30 ℃, little or no fertilizer should be applied, and the amount of water should be reduced accordingly to prevent the leaves from yellowing after rotting roots. If it turns yellow, the reason is the lack of nitrogen fertilizer, the breeders can apply cake fertilizer appropriately. At the same time, 0.1-0.2% ferrous sulfate solution can be sprayed on the leaves every day. Strengthen the light in winter, it is best to have a fixed time every day, give the gentleman orchid sunbathing. After such observation and management, yellow disease seldom occurs in Magnolia.