The branches of young walnut trees are easy to dry up in winter. Key points of cold prevention of young walnut trees in winter.

Newly planted walnut trees are prone to dry branches in winter, which is caused by large pith, high water content and poor cold resistance of young walnut trees. After investigation and research, walnut growers summed up a set of management methods for cold prevention of young walnut trees.

Young walnut trees

1. Burying the soil to prevent cold: for the 1-2-year-old walnut young trees that can not survive the winter safely in the open field, leave the walnut seedlings for 15-20cm stubble, then cover the soil strictly, sprout in the second year, shovel and cover the soil. This method is the most effective and reliable measure to control walnut trees.

two。 Cultivate soil to protect against cold: cultivate a mound within the range of 30cm at the base of the seedling to prevent frostbite on the rhizome and grafting interface of walnut trees. Remove it after the temperature picks up next spring and flatten the tree plate.

3. White against cold: young trees can reduce the temperature difference between the yin and yang of the trunk, prevent the main branches and trunk frost injury and sunburn, white against cold, the effect is better, can be applied before the soil is frozen. The formula of whitening agent: 40 parts of water, 10 parts of quicklime, 2 parts of stone-sulfur mixture and 1 part of salt.

4. Cover grass against cold: protect young walnut trees from cold 1-3 years after planting. That is, in winter, straw, sacks, woven bags, straw mats are used to bind the trunk and main branches, and then bind both ends to protect young walnut trees from wind and cold, so that young walnut trees can survive the winter safely.

5. Polyvinyl alcohol (PVA) drying: evenly brush the trunk of walnut trees with boiled PVA. Polyvinyl alcohol preparation method: polyvinyl alcohol: water = 1:15-20. First boil the water to about 50 ℃, then add polyvinyl alcohol (can not wait for the water to boil again, otherwise polyvinyl alcohol can not be completely dissolved, the solution is uneven), stir with the addition until it boils, and then simmer for 20-30 minutes. Use when the temperature drops to the point where it is not hot.

6. Irrigation against cold: irrigation of walnut trees before freezing can prevent drought in winter and spring and promote the growth of walnut trees. at the same time, it can also make use of the characteristics of water accumulation of more heat to stabilize the ground temperature in cold and winter and reduce the freezing damage of walnut trees.