A Complete Analysis of the Latest Management Key Points for the Grape Bleeding Period

From the time the sap flows in early spring until the buds sprout and leaves unfold, this period is called the grape bleeding period. At this time, the grape root system begins to absorb water and nutrients from the soil, and the liquid within the tree begins to flow. If pruning is improper or a wound is accidentally caused at this time, the sap will flow out from the wound, which is the bleeding phenomenon. The bleeding sap contains a large amount of water and nutrients, and bleeding is extremely harmful to tree growth, ranging from reduced yield in mild cases to plant death in severe cases, so the grape bleeding period is extremely important. Let us take a look below.

1. Timely removal from the soil

For grapes not buried with soil for winter protection, complete pruning and orchard cleaning and trellising before bleeding occurs. For grapes buried with soil for winter protection, timely removal from the soil is of great significance for robust sprouting and growth. If removed from the soil too early, the root system has not yet become active enough, the branches and buds have already been dried out, and premature aging and frost damage may also occur; if removed too late, the buds are very easily knocked off during trellising, causing bleeding. The best time should be in early to mid-April, so that the plants gradually adapt to the external environment.

2. Timely watering

After the grapes are removed from the soil and trellised, start watering with bud water. The irrigation amount should be enough to moisten a soil layer of more than 50 cm. In regions with spring drought and little rain, water thoroughly in one go to meet the needs of bud sprouting and shoot growth. In non-buried areas, based on rainfall conditions, apply bud-forcing water well before sprouting.

3. Scientific fertilization

Fertilization during the grape bleeding period should mainly use quick-acting nitrogen fertilizer. Commonly used fertilizers include urea, monopotassium phosphate, potassium sulfate, boric acid, etc. Because grapes are relatively sensitive to chloride ions, it is not recommended to use chloride-containing fertilizers such as potassium chloride. The demand of grapes for potassium far exceeds that for nitrogen fertilizer and phosphate fertilizer, so more potassium fertilizer should be applied. For orchards that did not apply base fertilizer in the previous autumn and winter, at this time organic fertilizer can only be applied into a soil layer of more than 30 cm. Fertilization must not be too deep, so as to avoid damaging the roots and causing bleeding.

4. Raising soil temperature

The early spring climate is changeable, rising and falling suddenly, and after watering the low temperature recovers slowly. Therefore, after land preparation, fertilization and watering, white plastic film should be fully covered between the rows to rapidly raise the soil temperature. At the same time, it is necessary to eliminate weeds, reduce pests and diseases, maintain soil moisture, and improve soil structure.

  The above is an introduction to the management key points during the grape bleeding period. We hope it can help you. To learn more related knowledge, please follow us.