Causes and control of yellowing of bonsai leaves of winter red fruit

The winter red fruit is easy to bloom, the fruit setting rate is high, the fruit is all red, and the hanging fruit period can be extended to the flowering and long leaves of the following year without falling off. it is an excellent variety of bonsai and is deeply loved by the people. However, in the process of cultivation, the leaves are often yellowed and shedding due to the limitation of basin capacity and other effects. The main causes of yellowing are as follows:

Warm

Winter red fruits like warm and humid conditions, like light but not too strong, especially in hot summer, strong direct sunlight will make the air dry, basin soil temperature rise, cause root system damage, reduce enzyme activity, cause leaves to turn red, leaf tips dry, yellowing and withering. To this end, in summer, it should be placed in a ventilated place, and often spray water around the tree to reduce the air temperature.

Strong light irradiation is easy to appear branches and leaves withered, wilting, tip scorched, while weak light irradiation can easily lead to excessive growth of branches, poor coloring of fruits, small and yellowing leaves. Therefore, when the winter red fruit enters the viewing period, the indoor display should be close to the windowsill to make it under the bright scattered light.

water

Due to excessive watering of basin soil, ① caused stagnant water, made basin soil anoxic, some fibrous roots asphyxiated and rotted, lost the ability to absorb water and nutrition, and respiration increased bicarbonate ion (HCO3), which affected iron absorption, resulting in light yellow and wilting of young leaves at the top and gradually dark yellow of old leaves. If you find this phenomenon, you should immediately remove the plant from the basin with soil balls, put it in a cool and ventilated place, often spray water to the leaves, and stop spraying water to the roots, so that the water will evaporate as soon as possible. Wait for the plant to return to normal before potting.

In the ② basin soil, it is normal for the winter red fruit to appear the center and the new leaf color, but the lower old leaves gradually dry yellow, curl and fall off, the fruit shrinks and the fruit falls seriously, although the winter red fruit is not watered for a long time or not. When this happens, do not immediately pour water into the basin soil, first put it in the semi-shade, spray water to the leaves first, and wait for the leaves not to wilt, use the soaking method to make the basin soil slowly soak with water, such as watering, because the cracks in the basin wall are loose, water is easily lost from the cracks, resulting in watering impermeable. In short, we should follow the principle of "no dry, no watering, watering thoroughly".

③ Donghongguo likes slightly acidic soil. Due to the alkalinity of water in the north, the basin soil tends to be alkalized gradually due to long-term watering, so that the plant can not absorb iron. In the process of cultivation, 1 part of ferrous sulfate, 10 parts of bean cake fertilizer and 200 parts of water are often used and diluted after ripening to change the alkalinity of basin soil.

Fertilizer

① fertilized too much and concentrated too much, resulting in yellow leaves. The new leaves are thick and glossy, the leaves are dark green, but the back of the leaves are wrinkled and protruding, the leaves are not stretched, and the old leaves in the lower part of the plant gradually turn yellow and fall off. At this time, the winter red fruit should be placed in the shade, the flowerpot should be soaked in water to dilute the fertilizer, and two hours later, the plant should be removed from the pot with soil balls and dried. If necessary, remove the old leaves and get rid of some of the old soil in exchange for new soil.

② winter red fruit has strong growth and needs to be changed every 2-3 years, otherwise it is easy to form root mat, resulting in poor air permeability of basin soil, difficulty in absorbing water and fertilizer by root system, thin and weak branches, long internodes, thin and tender leaves, poor flower color, and difficult to set fruit. For this reason, in the dormant period, it should be combined with root pruning to change the basin and soil.

During the cultivation of ③, due to the application of immature organic fertilizer, the fertilizer was fermented in the basin, resulting in root burn or poisoning, root blackening, rot, leaf wilting and yellow, and even the whole plant withered. Therefore, the application of organic fertilizer must be mature.

The difference between iron deficiency and manganese deficiency: the chlorosis degree of iron deficiency is usually dark, the yellow-green color boundary is often obvious, there is generally no brown spot, while the chlorosis degree of manganese deficiency is shallow, and brown spots or brown strips often occur.