Citrus leaves have an important position for the growth of fruits and the tree posture of fruit trees, the leaves can photosynthesis, provide nutrients to fruit trees, and there is also a shade tolerance, can weaken the direct radiation of ultraviolet rays, protect the growth of trees and fruits.
Citrus leaves are an important organ of the tree body to store organic nutrients, and normal citrus leaves are turquoise, which will cause yellowing and shedding if they are due to insect infestation, frost damage, cold damage or improper cultivation management measures. The nutrients in the leaves are basically not returned, and a large amount of nutrient loss will be caused.
There are several causes of yellowing of leaves
1, leaf nitrogen deficiency, iron, zinc, boron, manganese and other nutrients may appear leaf yellowing problem, serious will all turn yellow, if not serious, there will be a part of the yellow part of the green leaves.
2, diseases and insect pests lead to yellowing of leaves, pathogens and other pathogens invade the citrus tree body, the production of various secretions can block the citrus transport system, resulting in the inability to absorb water and nutrients, photosynthesis necessary raw materials can not be supplied, the leaves will appear green yellowing. For example, yellow dragon disease, red spiders, mesozoites, leaf curls, and nematodes can cause citrus leaves to turn yellow.
3. Damage to the roots, or yellowing problems, resulting in the inability to absorb nutrients from the soil and supply to the tree, will lead to yellowing of the leaves.
4. The temperature is too high or too low, resulting in temperature discomfort, soil nutrients are not easy to activate or release, and crops are difficult to absorb, resulting in late germination in spring and yellowing of leaves.
5, improper fertilization, some fertilizers such as nitrogen fertilizer, too much application, excessive leaf nutrition, will also turn yellow.
Citrus leaves turn yellow, which is not conducive to the growth and development of fruit trees and fruits, so in the management process, it is also necessary to protect the leaves of fruit trees in order to promote growth.
1, soil modification, fertilization, the fundamental way to prevent iron deficiency disease is to improve the soil and do a good job in drainage and irrigation systems, to prevent drought and flood disasters, alkaline soil should be applied more organic matter fertilizer, pay special attention to the application of more green manure, soil fertilizer and other acidic fertilizers.
2. Appropriate circumcision, control the shoots and promote flowers, but improper circumcision can easily lead to the death of yellow leaves or the whole tree. Therefore, caution should be exercised when circumcising.
3. Rational use of fertilizer to avoid drug damage and fertilizer damage. Drought not only affects the vitality and absorption of the root system, but also easily induces red spiders, which should be filled with horse water in time during drought.
4, supplement trace elements, it is recommended to dig a pit to bury some trace elements, common water-soluble trace elements have a good effect, do not hurt the roots.