Causes and Control Measures of Abnormal Falling Leaves of Citrus in Winter

Citrus is one of the most common fruit trees in our life. It is an evergreen fruit tree. There are few defoliations in autumn and winter. Once abnormal defoliation occurs, it will definitely affect the yield and quality of the coming year. So what is the cause of citrus abnormal defoliation in winter? Let's take a look at it together with Xiaobian.

I. Causes of abnormal citrus leaves in winter

1. Lack of nutrition

When citrus lacks N, P, K, Ca, B and other trace elements in winter, it will cause yellowing and shedding of leaves, which is one of the main reasons for citrus defoliation.

2. Water imbalance

When the soil is too dry, the root growth of the plant is inhibited, and when the evaporation of the plant is greater than the absorption of the root, then the leaves will be withered and curled, and the petioles will fall off in severe cases. In addition, when the water is accumulated, the permeability of the soil is poor, inhibiting the respiration of the roots, and the roots will rot for a long time, which will also cause yellowing of the branches and leaves on the ground, defoliation, and serious death.

3. Poor lighting

The growth and development of leaves are inseparable from photosynthesis. If the plant is closed and the light is insufficient, the inner bore leaves will increase and thin. The leaves are dull or even yellow. In winter, the light is weak, and if it is not improved for a long time, it will cause a large number of leaves in the bore.

4. Maintain hazards

Red spider, scale insect, anthracnose and yellow spot disease will cause the greatest harm in citrus growth period, and timely prevention and control will cause a large number of leaves in spring and winter.

5 Other reasons

In addition, phytotoxicity, fertilizer damage, strong wind, freezing injury and ring cutting may cause abnormal citrus defoliation.

II. Prevention and control measures

1. Strong tree vigor

In production, phosphorus, potassium fertilizer and organic fertilizer should be applied in combination with deep ploughing, so that the root system can be deeply rooted, foliar fertilizer should be sprayed at the same time, reasonable pruning and timely irrigation should be carried out to cultivate strong tree vigor and improve tree body resistance. For plants with phytotoxicity, foliar fertilizer and brassin can be sprayed on crown branches and leaves to alleviate the defoliation phenomenon caused by improper ring cutting, foliar fertilizer should be sprayed in time or electric adhesive tape should be used to bond the ring cutting mouth, and at the same time, within one month after ring cutting, pesticides such as sulfur mixture should be avoided.

2. Do a good job in pest control

Before overwintering, it is necessary to do a good job of clearing the garden comprehensively to reduce the base number of diseases and insect pests. Adding 2,4-D to the clearing garden is conducive to freezing and leaf protection. For a large number of leaves caused by anthracnose and macular disease, once found to need timely control, reduce harm, timely spray control in the growing season, protect leaves.

3. Pay attention to freezing

In addition to measures such as proper planting, applying sufficient base fertilizer and painting white trunk, attention should be paid to spraying citrus leaves in winter only before freezing after fruit picking; secondly, emergency freezing measures should be taken, spraying and potassium dihydrogen phosphate solution in time before frost to slow down tree thawing and restore leaf function.

4. Supplement nutrients

In production, attention should be paid to deficiency disease. Once it is found, it should be prevented and treated in time. What fertilizer is lacking should be applied.

The above is an introduction to the causes and control measures of citrus abnormal defoliation in winter. I hope it can help you. If you want to know more about it, please pay attention to us.