Key points for grape management in December

Winter is a critical period for vineyard management, and the quality of management is directly related to the growth and fruiting of grapes in the following year. For newly built vineyards, park planning, land preparation and trellising are required to prepare for the planting of seedlings. In most grape-growing areas in the north, grape plants are susceptible to low temperature damage due to the dry, windy and low temperature in winter. The branches may lose water or even dry up due to the dry and cold wind. In order to ensure that the grape plants survive the winter safely and guarantee a good harvest next year, wintering management must be done before winter comes. Now it is December, let’s learn together the key points of grape management in December.

1. Soil improvement and fertilization

In the north, it is recommended to apply base fertilizer to grapes in autumn and complete it by the end of November at the latest. Applying basal fertilizer after the beginning of winter is not effective. The soil needs to be deeply tilled to improve it before fertilization. Method of applying basal fertilizer: For adult fruit-bearing trees with a spacing of less than 1.5 meters, dig a ditch 60 to 70 cm away from the main trunk of the plant, 50 to 60 cm deep and 40 to 50 cm wide, and apply composted livestock and poultry manure, various cake fertilizers, soil and miscellaneous fertilizers and other organic fertilizers . Per mu, you can apply 3-4 cubic meters of decomposed chicken manure, 4-5 cubic meters of sheep manure, 5-6 cubic meters of pig manure, 10-15 cubic meters of cow manure, or an appropriate amount of special biological fertilizer for fruit trees (nitrogen-fixing bacteria, Bacillus subtilis, enzyme bacteria), as well as 100-200 kg of cake fertilizer, 50-100 kg of superphosphate, and 20-30 kg of wood ash. Mix the fertilizer and soil in layers and apply them into the trench for backfilling. Fill the trench with water immediately after application.

2. Garden Cleaning

1. Clean up the dead branches and leaves

As the temperature drops, many pests and diseases will overwinter underground with the dead branches and leaves. Therefore, after the grape leaves fall in winter, the vineyard generally needs to be disinfected and cleaned. The specific method is to collect all the dead leaves and branches on the ground of the vineyard after pruning the entire garden and burn them together, and spray the entire garden with 3-5 degree lime sulfur mixture once to reduce the overwintering of pathogens and insects.

2. Peel off the bark of the old tree

The bark of some grape vines that are more than three years old will crack, and some pests and diseases will burrow into the bark to hibernate, becoming a source of pests and diseases in the next year. Timely peeling off the bark of old ash trees and burning them in a concentrated manner can reduce the overwintering places for pests and diseases and lower the base number of pests and diseases.

3. Whiten the tree trunk

In December, especially after the beginning of winter, the temperature drops, cold air sinks, and the part above the root neck of the grape is prone to frost damage. At this time, using whitewash to whiten the tree trunks can effectively prevent frost damage, prevent pests and diseases from overwintering on the trunks and old bark, kill pathogens and insect eggs overwintering on the trunks, reduce the overwintering places for pests and diseases and the base number of pests and diseases, reduce the workload of pest and disease prevention and control in the coming year, and achieve twice the result with half the effort.

4. Pour antifreeze water

Flooding the trees with water before the soil freezes can effectively prevent the trees from freezing.

3. Winter pruning

Grape pruning is the process of cutting back the plants to remove diseased and insect-infested branches and vines, eliminate some overwintering pests and diseases, maintain a high-yield and high-quality tree shape, regulate the balance between growth and fruiting, perform renewal pruning, prevent the fruiting part from rising, ensure that the tree is strong, the branches and vines are evenly distributed, the subordinate relationships are clear, and a good skeleton structure is formed. This ensures a good ventilation and light environment in the vineyard in the coming year, creating conditions for continued high yields and high quality year after year.

The best time to prune grapes in the winter production area that does not need to be buried in the soil to protect against the cold is from mid-to-late December (usually around the winter solstice) to one month before sap flow, so as to avoid excessive sap flow that weakens the tree. For winter pruning of grapes in production areas that are buried in the soil to protect them from the cold, pre-pruning is generally done before burying the grapes in the soil, and re-pruning is done after they emerge from the soil in spring.

For winter pruning, it is advisable to select healthy and well-matured one-year-old branches as fruiting mother branches. The thickness of the cut is generally between 0.8 and 1.2 cm. When pruning annual branches, the cut should be 3 to 4 cm above the branch node, and the cut should be slightly inclined opposite the bud. The cut can also be made at the node to break the buds. When thinning out annual branches and old vines, they should be removed completely from the base, leaving no short stumps. But at the same time, be careful not to make the wound too large so as not to affect the growth of the mother branch. The cut should be flat and smooth. When removing old vines, the saw cuts should be flattened to facilitate healing. Try to keep the pruning wounds from different years on the same side of the main vine to avoid causing opposite wounds. When pruning long- and short-tip fruiting branches, in principle, all long-tip fruiting mother branches (two-year-old branches) should be cut off, and the two one-year-old branches growing on the replacement short branches below them should be cut to form a new long- and short-tip fruiting branch group. In order to ensure that the wound after thinning of the long-shoot fruiting mother branches is located on the same side of the old vine, the first good bud at the base of the replacement short branch should face the outside of the branch group, and then be cut after leaving another good bud on it. The replacement short branch should be formed by pruning the strong one-year-old branch.

The above are the key points of vineyard management technology in December. Grape growers should refer to and learn from them based on the actual situation of their own orchards .