Osmanthus fragrans is fragrant and charming. It can afforest the environment and clean the air. However, if you don't pay attention to it, the leaves will turn yellow. However, how can you prevent the leaves from turning yellow? And how do we deal with yellowing? This paper will analyze the causes of the yellow leaves of Osmanthus fragrans and seek solutions.
The reason analysis and treatment methods of Osmanthus fragrans leaves yellowing: 1. Excessive watering leads to the yellowing of Osmanthus fragrans leaves (water yellowing): in case of waterlogging, the root system will be black and rotten, the leaf tip will be scorched first, and then the whole leaf will wither and fall off, leading to the death of the whole plant.
Solution: if the disease is serious, the whole land needs to be removed from the basin and placed in the dry soil pile to make the water seep out quickly, and then replant into the basin after the drooping branches and leaves recover.
2. Long term water shortage causes the leaves of Osmanthus fragrans to turn yellow (dry yellow): if the water is too little, or if the water is half cut off or omitted for a long time, the water evaporation of the leaves is greater than the absorption, resulting in the water shortage, it will also cause the leaves to turn yellow“ "Hanhuang" is gradually yellowing from the lower leaves, withering and falling off, and the petiole droops and wilts when it is serious.
Solution: immediately move the flowerpot to a cool place, spray some water on the leaf surface, and pour a small amount of water. Later, as the stems and leaves gradually return to straight, and then gradually increase the amount of water, if too much water is suddenly poured at this time, it may cause the separation of cytoplasmic wall, protoplasm damage, and cause the death of flowers.
3. The leaves of Osmanthus fragrans are yellowing due to the sun exposure: in summer, it is easy to cause the tender leaf bud or the leaf edge withering or the whole leaf yellowing if it is maintained in the strong light.
Solution: it should be moved to a cool place with good ventilation immediately after discovery. If the temperature rises or dryness, shade and spray should be adopted to improve the environmental humidity. Generally speaking, the tip of the old leaf can be improved as long as the humidity is increased by more than 60%.
4. Insufficient sunlight causes the leaves of Osmanthus fragrans to turn yellow (lack of light yellow): if it is kept in the room for a long time, it will grow weak, the leaves will become thin and yellow, and will not bloom or rarely bloom.
Solution: suitable arrangement of Osmanthus see light degree and see light time. In order to cultivate this kind of flowers, it is usually necessary to put them outdoors in the sunny or semi light place, and then move them into the indoor view after flowering.
5. Excessive fertilization of Osmanthus fragrans trees leads to yellowing of leaves (yellowing): excessive fertilization, especially excessive nitrogen fertilizer and lack of phosphorus and potassium fertilizer, is easy to cause yellowing of leaves, which is characterized by hypertrophy of new leaves, uneven surface of leaves, yellowing and falling off of old leaves, dry tip and even yellowing of whole leaves.
Solution: in case of this situation, fertilize immediately, increase the amount of watering, let the fertilizer flow out from the drain hole, or pour the pot immediately, remove part of the old soil, wash the soil lump with water, replace part of the new culture soil, and then plant the plant in the pot again.
6. The leaves of Osmanthus fragrans are yellow due to long-term lack of fertilizer (yellow due to lack of fertilizer): lack of fertilizer, especially the lack of nitrogen nutrition in the soil without long-term application of nitrogen fertilizer or change of basin soil, resulting in thin and yellow branches and leaves.
Solution: pour the pot in time, take out the plant, replace it with a larger pot, put in a new loose and fertile culture soil, and replant it. After pouring the water, put the seedling in the semi open place to slow down. After the plants grow again, thin liquid fertilizer or compound fertilizer is applied.
7. Rotten roots lead to yellow leaves of Osmanthus fragrans trees: the damaged parts of rotten roots are water stains, and the disease spots gradually expand, resulting in weak plant growth and even death. This disease often occurs in rainy season in summer and autumn. The reason is that the soil is too wet, which weakens the resistance of root system and makes the pathogen take advantage of the deficiency.
Solution: sprinkle a small amount of sulfur powder around Osmanthus fragrans in early spring to kill rhizosphere bacteria. In winter, the trunk was whitewashed with a mixture of 25 kg quicklime, 3 kg salt, 0.5 kg vegetable oil, 1 kg sulfur powder and 100 kg water. Strengthen ditch cleaning and drainage in rainy season. When the disease spot appeared on the trunk of Osmanthus fragrans, it could be scraped clean and then coated with thiram kerosene, and at the same time, the root could be irrigated with 500 times dicoform. The dead plants should be excavated and burned in time, and the soil of the original planting site should be irrigated with quicklime water for disinfection to prevent the spread of pathogens.
8. Diseases and insect pests lead to yellow leaves of Osmanthus fragrans
In the early stage of the disease, small chlorotic macular spots appeared on the leaves and gradually expanded into near round spots. The disease generally occurred from April to October, and the old leaves were more susceptible than the tender leaves.
The pathogen of leaf blight mostly invades from leaf edge and leaf tip, and occurs at leaf edge and leaf tip. In the early stage of the disease, light brown spots appeared on the leaves, gradually expanded into round or irregular spots, and then expanded into nearly round or irregular large gray brown spots with dark brown edges. Leaf blight occurs from July to November, and can occur all year round in the greenhouse with poor environmental conditions.
Anthracnose, which infects the leaves of Osmanthus fragrans. At the early stage of the disease, small chlorotic spots appeared on the leaves, and gradually expanded to form round, semicircular or oval lesions. The lesion was light brown to grayish white with reddish brown ring on the edge. Under moist condition, the myxospore disk appeared in pink color. Anthrax occurs from April to June.
Solution: first, reduce the source of infection. In autumn, the diseased leaves were completely removed. Potted osmanthus should be removed in time. Secondly, strengthen the cultivation management. Choose fertile and well drained soil or substrate to plant Osmanthus fragrans; Increase the application of organic fertilizer and potassium fertilizer; The planting density should be appropriate, so as to ventilate and transmit light, reduce the leaf humidity and reduce the occurrence of diseases. Scientific use of chemical control.
Sweet scented osmanthus tree maintenance experience: 1, need timely increase ventilation. It is suitable for planting in the place of ventilation and light transmission; Like clean and ventilated environment, not resistant to smoke hazards.
2. The water quality is not good. In the northern part of China, the plants that like acid soil, such as Osmanthus fragrans, will lose their green and turn yellow due to the lack of soluble iron elements that can be absorbed by flowers after a period of cultivation. At the same time, potassium dihydrogen phosphate also contains phosphorus and potassium elements, which is conducive to flower bud differentiation and improve the quality of flowers.
3. The soil is slightly acidic. The southern part of China is red soil. The soil is acidic or slightly acidic, and the magnesium element in the soil is easy to be lost. The leaves often show green and yellow between the old leaves and veins due to the lack of magnesium. If calcium magnesium phosphate fertilizer can be applied, evergreen will suffer, causing the leaves to yellow and fall off; If the room temperature is lower than 5 ℃, most of the flowers that like warm and fear cold will also suffer. The leaves, flowers and fruits will turn yellow, dry and easy to fall off. Therefore, after entering the room, 0.1% to 0.3% magnesium sulfate solution should be sprayed according to or. For the improvement of acid soil, we should pay more attention to the application of decomposed organic fertilizer and lime. A small amount of lime can not only neutralize the soil acidity, but also promote the decomposition of organic fertilizer.
4. In winter in North China, the indoor air is dry due to heating with heating or raw coal. Some flowers like to have moist air. Under such environmental conditions, they are prone to withered leaf tips or withered leaf edges, scorched spots and curled edges. They should be sprayed with warm water close to room temperature and put a basin of clean water on the radiator or stove, In order to increase indoor air humidity. For some rare flowers, it's better to cover them with plastic film at night, and the leaves are scorched locally, or even the whole plant is dead. Therefore, we should pay attention to the rational use of pesticides, try to eliminate air pollution and avoid soil toxicity.