How to treat yellow leaf disease of pear tree

Pear yellow leaf disease is a physiological disease, which is caused by iron deficiency. In this situation, corresponding measures should be taken. How to treat pear yellow leaf disease?

1. Causes of yellow leaf disease of pear trees

Pear yellow leaf disease is a physiological disease, which is caused by iron deficiency. General soil is rich in iron, but in alkaline soil, a large amount of soluble divalent iron is converted into insoluble trivalent iron salt and precipitated, which can not be absorbed and utilized, so that pear trees show iron deficiency (yellow leaves). In addition, the application of a large amount of available nitrogen fertilizer leads to soil consolidation and iron fixation. Sandy soil, strong permeability, easy to lose iron, serious disease; spring branches and leaves grow vigorously, need a large amount of iron, easy to lead to iron deficiency; low-lying, heavy soil viscosity, poor drainage, serious disease.

How to treat the yellow leaf disease of pear trees

1. Irrigation and washing salt in spring, timely elimination of stagnant water, control of salt rise, and application of organic manure and green manure in orchards to improve soil.

2. Before germination, each big tree was mixed with ferrous sulfate or chelated iron 0.5-1kg mixed with 5 times organic fertilizer into the soil, and irrigated after application. Spraying 0.3-0.5% ferrous sulfate solution on the branches, or spraying a mixture of ferrous sulfate, copper sulfate, quicklime and water in the ratio of 1-1-1-1-2. 5-300 has a significant effect on controlling the occurrence of the disease, but the effect period is short.

3. After the pear trees germinated, they were sprayed with 200 times of ferrous sulfate solution, or 100 times of ferrous sulfate acidified solution was injected into the trunk with a powerful trunk syringe. 20-30g ferrous sulfate was successfully used for each tree, and then used in a large area to avoid causing great losses.

4. After the yellow leaf disease is found in the growing period, iron fertilizer can be sprayed in time, usually once every 7-10 days, until the leaves turn green. The suitable agents are 200-300 times liquid of rapidly available iron, 500-600 times liquid of Huangyeling, 200-300 times liquid of ferrous sulfate, etc., and about 1% urea can be added to the liquid when spraying.

The control methods of pear yellow leaf disease are mainly adjusted from the supply of fertilizer and iron.