What are the advantages of grape green branch grafting? What are the relevant technical points?

Green branch grafting is a commonly used method for raising seedlings. In the growing season, green branches were used as scions and rootstocks for green branch grafting, and the seedlings obtained were called green branch grafted seedlings. What are the advantages of grape green branch grafting? What are the relevant technical points?

I. the advantages of grape green branch grafting

For hard branch grafted seedlings, the grafting wound generally heals slowly and unevenly, and the survival rate of grafted seedlings is low. the problem of irregular growth and development of grafted seedlings often occurs in vineyard. Compared with hard branch grafting, green branch grafting has the advantages of fast wound healing, good healing, high survival rate and high grafting efficiency, which has become the main method of grape grafting seedling cultivation and variety improvement in recent years.

2. Key points of grape green branch grafting.

1 types of rootstocks

The cold-resistant rootstocks were Beida and Shanhe 1, 2, 3 and 4, and the rootstocks resistant to root nematodes and aphids were SO4. At present, Beida is widely used in the north and SO4 is widely used in the south.

2 cultivation of rootstocks

In order to make the rootstock cuttage grafting in the same year, it is necessary to use nutrition bag to raise seedlings. Use the 10cm high and 10cm caliber plastic bag sold on the market, cut a small hole with a diameter of 1cm or cut the two corners of the bottom of the bag to facilitate drainage. At the same time, the nutritive soil was prepared with soil, sifted fine sand and rotten barnyard manure according to the ratio of V sand: v soil: v fertilizer = 2:1:1. Put the soil into a bag and put it into a sunny bed to raise seedlings. Cuttings were carried out in Liaocheng, Shandong Province in mid-March. Cut the stored cuttings into bud segments, the sturdy branches can be cut into single-bud cuttings, and the thinner branches can be cut into double-bud cuttings, cut flat at 1 cm above the bud eye, and leave 8 cm oblique cut under the bud (double-bud cuttings are cut obliquely near the second bud, cut into a Maltese shape). After the cut bud segment is treated with root-promoting agent, it is inserted directly into the center of the nutrition bag, and the top bud of the cuttings is flat with the soil surface in the bag. After the cuttage was finished, it was irrigated once, and an arched bracket was set up on the sunny border, covered with plastic film. Keep the temperature in the border at 20-30 ℃ in the daytime and above 10 ℃ at night. The management after cutting is relatively simple, mainly to maintain proper humidity in the bag and avoid waterlogging in the bag. When the nutrition is insufficient, 0.3% urea and potassium dihydrogen phosphate can be sprayed one or three times after the growth of 2 or 3 leaves. When the seedlings grow to 20 cm, they can be planted in the open field in mid-late May. The management of fertilizer and water should be strengthened after planting, and it can be grafted in the middle of June.

3 scion collection

The scion is collected from the plants with pure varieties, strong growth and free of diseases and insect pests, and can be combined with the work of thinning branches, coring and removing auxiliary shoots in summer pruning. It is best to take it near the nursery and pick it up with scissors, with a high survival rate. When it needs to be taken from other places, the cut green branches should remove the leaves in time, wrap them in fresh wet towels and plastic film or put them in a wide-mouth thermos flask, put a little ice at the bottom of the bottle, and keep the scion fresh for 2-3 days on the way.

4 grafting method

First of all, select the semi-lignified green branch scion, the bud eye had better make use of the newly germinated summer buds without spitting leaves, the survival rate is high and the growth is fast after grafting. If the summer buds have grown 3-4 leaves, remove the secondary shoots and use the winter buds. Winter buds germinate slowly, but grow fast and stout after germination. The thickness and maturity of rootstock and panicle branches are the same, and the survival rate is high. Before grafting, the green branches of the scion are interrupted at each bud node with a sharp bud knife or shaving blade, and stored in a basin covered with wet towels. When grafting, the rootstock leaves 3-4 leaves, remove the bud eye, truncate the above part, split vertically in the middle of the section, 2.5-3 cm long. Select the scion that is similar to the thickness and maturity of the rootstock, cut a slope of 2.5 cm and 3 cm downward from both sides at about 0.5 cm below the bud, showing a wedge shape, and the bevel knife edge should be smooth. Cut the scion and insert it into the incision of the rootstock immediately, so that the cambium on one side of the two sides is aligned, and the scion slope should be exposed 0.5 mm, which is conducive to healing. Then use a thin plastic strip 0.5 to 0.6 centimeters wide, winding upward from the bottom of the rootstock joint, only exposing the buds to the upper edge of the scion, and then wrapping it back to the bottom to tie a loose knot.

5 Field management of grafted seedlings

Irrigation in time after green branch grafting to do a good job in removing sprouting and disease control of rootstocks. Promote the normal growth of scion buds and remove other redundant branches in time. When the scion branch grows to about 50 cm, set up an iron wire along the grape seedling, and then tie the branch up. From July to September, Bordeaux solution was sprayed every 10 days to control downy mildew. Imidacloprid and cypermethrin were sprayed every 20 days or so to control leafhopper damage.