What are the symptoms of apple suffering from yellow leaf disease? How to cure it?

Apple leaves yellowing is not only a normal growth and metabolism phenomenon, but also may be suffering from yellow leaf disease. There are many reasons for yellowing leaves. It must be distinguished to cure the disease. Once the disease occurs, it will affect the yield and quality of apples, which is a very serious problem for fruit growers. What are the symptoms of yellow leaf disease? How to cure?

What are the symptoms of yellow leaf disease?

Apple once the occurrence of yellow leaf disease, then the new treetops tender leaves start to become, at first the leaves become yellow flesh, veins are still green, with the development of yellow leaf disease more and more severe, the whole leaves appear yellow-white. If it is a serious disease of apple trees, the whole edge of the leaves are scorched, and even the top directly appears dead phenomenon, it is affecting the normal growth of fruit trees.

The severity of apple yellow leaf disease is related to the texture of soil. Generally speaking, most of the causes of apple yellow leaf disease are caused by iron deficiency in apple trees due to iron deficiency in soil. If the soil is sandy, the incidence of fruit trees is lower. If the soil is alkaline or the lime in the soil is too high, the apple trees cannot absorb iron.

The severity of yellow leaf disease of apple trees is also related to the type of rootstock. If it is alkaline resistant, it is sensitive to iron deficiency. The yellow leaf disease of apple trees with St. Malus L. as rootstock was more serious than that with Malus L. as rootstock.

How to cure apple yellow leaf disease?

1. Improve the nature of the soil

Apple orchards planted with legume grass, and then increase the use of organic fertilizer, so that can change the soil permeability and soil rationalization characteristics, thus strengthening the vitality of root microorganisms.

2. Increase the use of organic iron fertilizer

Ferrous sulfate can be added before apple trees sprout or when applying base fertilizer in autumn. Remember, it cannot be used for a long time. The specific method is to mix ferrous sulfate and decomposed organic fertilizer according to the ratio of 1:15, stir evenly, then dig a circular ditch with a depth of 50 cm and a width of 70 cm along the periphery of the apple tree crown, put the organic iron fertilizer that has been stirred into the ditch, and irrigate it with water immediately after covering the soil. The specific amount used depends on the age of the plant. A young apple tree needs about 30 kilograms, and a ten-year-old tree needs about 80 kilograms of organic fertilizer.

3, foliar fertilizer

Foliar fertilizer, then according to the apple tree leaf growth period to determine, tender leaves, then can be applied amino acid iron, compound iron fertilizer solution. During the period of flourishing growth, foliar fertilizer should be used reasonably to avoid excessive fertilization causing the phenomenon of withered leaves.

4. Integrated management

Do a good job of soil improvement, selection of disease-resistant rootstocks, pay attention to the drainage of low-lying orchards to prevent excessive accumulation of water and rotten roots.