What Causes Bleeding in Grapes? A Detailed Guide to Prevention and Control

In spring, grapes commonly exhibit bleeding, which is mainly the flow of sap from wounds, resulting in a large loss of nutrients, reduced yield in mild cases, and death of the entire plant in severe cases. So what causes bleeding? How should it be handled? Let's take a look at the detailed introduction below.

I. Causes of Bleeding

Bleeding in grapes in spring is a common phenomenon. Generally, when the soil temperature reaches 6-10 degrees, the grape root system begins to become active, and the sap and nutrients of the tree body are transported along the xylem to all parts of the tree. If a wound is encountered during transport, they will flow out along it, and in severe cases they will drip like raindrops, which is extremely unfavorable to the growth and development of grapes and must be prevented and controlled in time.

II. Prevention and Control Measures

1. Proper pruning

Pruning of branches and vines should not be too early or too late. Too early will cause the tree's nutrients not to have returned in place, resulting in waste, while too late will enter the bleeding period, and a large amount of nutrients will flow out through the wounds, causing excessive consumption of nutrients. The best pruning time is generally 3-4 weeks after leaf fall, specifically between early December and the end of December. After pruning, attention should also be paid to protecting the wounds so that they heal as quickly as possible.

2. Protect wounds

To prevent bleeding, the best method is to protect the wounds. After pruning, white latex or pruning seal oil mixed with lime sulfur mixture residue can be applied to the wounds. This is convenient and quick, with low cost and good effect.

3. Improve tree resistance

Water and fertilize in time in spring to improve the cold resistance of the tree. Generally, irrigation is carried out in combination with fertilization, applying 0.25 kg of ternary compound fertilizer per plant, mainly potassium fertilizer, along with a small amount of biological bacterial fertilizer and trace elements. This can effectively improve the resistance of the plant and avoid a large number of wounds caused by freezing injury.

4. Comprehensive orchard cleaning

In winter, a thorough orchard cleaning should be carried out. First remove weeds completely, then gather the residual branches, fallen leaves and weeds in the orchard and burn them in a centralized manner, and manually scrape off insect eggs on the branches and vines to reduce sources of pests and diseases, so as to prevent pests and diseases from causing wounds and producing bleeding.

The above is an introduction to the causes of bleeding in grapes and the prevention and control methods. We hope it can help you. If you want to learn more related knowledge, please follow us.