Why should the trunk be painted white in winter?

Applying Bordeaux solution to the trunk can sterilize, kill eggs and prevent freezing injury.

Bordeaux liquid, bactericide, made of lime water and copper sulfate. Bordeaux solution has strong adhesion, which forms a film after spraying on the surface of plants, and gradually releases copper ions, which can prevent germs from invading plants. ? In addition, the copper in Bordeaux solution is absorbed by plants, which can play the role of trace elements, promote plant growth and improve its disease resistance.

At the same time, after wearing a white dress made of limewater, the trunk can reflect 10% sunlight. In this way, the heat absorption is reduced, and the trunk will not freeze and crack because of the huge temperature difference between day and night.

Extended data:

Whitening time: From the end of June 165438+ the middle of February next year, the trunk can be whitened. During this period, freezing can be prevented first, and then targeted pest control can be carried out, which will get twice the result with half the effort.

Whitewashing position: the whitewashing height is generally 1 ~ 1.5m from the ground, with emphasis on the root and neck of the trunk. For big trees and diseased trees with incomplete crowns, the southern part of the trunk should be painted. Ordinary branches, branches born in the same year, should not be painted white to avoid burning the cortex.

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