Recommended Best Time and Methods for Grafting Grapes

Grapes are one of the oldest fruit tree species in the world, native to western Asia, and cultivated throughout the world. So, when is it better to graft grapes? What grafting methods are recommended?

Grafting grapes using green shoots and buds not only saves scion material, achieves a high survival rate, is easy to perform, and allows a long grafting period, but failed grafts can also be re-grafted, and it is especially ideal for top-grafting large trees. The green shoot bud grafting technique is described below.

1. Selection of scions and rootstocks

Scions should be taken from vigorous new shoots of individual plants of currently excellent varieties in Xinjiang, such as Red Globe and Black Globe; remove the leaves but keep 1-2 cm of the petiole. Rootstocks can generally use cultivated varieties and wild Vitis davidii (spiny grape), etc., and undesirable large or small grape vines can also be used, grafting onto semi-lignified new shoots on the outer part of the canopy. Rootstock selection should meet 3 conditions: 1) good grafting compatibility, shown not only by good healing at the union but also by a good influence on the scion variety, so that the excellent traits of the scion variety are fully expressed, and after grafting there is no early decline and the lifespan is long; 2) wide adaptability, which can expand the cultivation range of the variety; 3) easy to propagate and easy to popularize. Scions should be collected and grafted immediately, taking care to keep them moist.

2. Grafting time

Green shoot grafting is suitable from early May to late July, and earlier grafting is better than later grafting.

3. Grafting methods

1. Cleft grafting

Same as ordinary cleft grafting. For the wound exposed at the upper end of the scion and the wounds on the petiole and tendril, seal them with plastic film to retain moisture, shaped like a cap.

2. Long cut grafting

Same as ordinary cut grafting, making full use of the internode length of grapes to create a larger healing surface. At 1/3 of the wider side of the scion, use a double-edged blade to cut straight and smoothly from bottom to top to the bud (node), do the same on the rootstock, then press the scion and rootstock tightly together and wrap them.

3. Bud grafting

Bud grafting is done on the internode of the rootstock's new shoot; the internode is straight and smooth, making grafting easy. Buds grafted on May 17 grew to 4 cm with 2 leaves by June 6. The grafted bud can also be inserted at the bud position of the rootstock, replacing a bud with a bud, and then wrapped well with plastic film; this method has little effect on the growth and fruiting of the rootstock's new shoot.

4. Post-grafting management

Check for survival 7 days after grafting; failed ones can be re-grafted, and about 15 days after grafting they will sprout and send out shoots. Secondary shoots (suckers) growing above and below the grafted site consume many nutrients and are unfavorable to the growth of the grafted buds, so they should be removed as appropriate. If the binding material at the union does not affect branch growth, it need not be removed, but the film seal should be cut open in time to favor the sprouting of new shoots. At the same time, set up supports and tie the shoots in stages, and strengthen fertilizer and water management and pest and disease control. Top-grafting large trees to change varieties can simultaneously graft multiple early-, mid-, and late-maturing varieties, but each variety should be clearly marked to avoid mistakes when collecting scions. The quality of grafted seedling management is one of the main factors affecting the survival rate of grape grafting; timely and thorough management gives a high survival rate, otherwise the survival rate is low. In production, in addition to normal shaping and pruning, pinching and trellising, fertilizer and water management, and pest and disease control for grafted seedlings, post-grafting sprout treatment, timely removal of binding tape, checking the survival rate, and timely re-grafting are indispensable measures for improving the grafting survival rate.

5. Effects and benefits of grapes

Grapes are not only delicious but also highly nutritious. In ripe berries, the sugar content of grapes is as high as 10%-30%, mainly glucose. The various fruit acids in grapes aid digestion, and eating a proper amount of grapes can strengthen the spleen and stomach.

Grapes contain the minerals calcium, potassium, phosphorus, and iron as well as multiple vitamins including vitamin B1, vitamin B2, vitamin B6, vitamin C, and vitamin P, and also contain various amino acids needed by the human body. Regular consumption of grapes is greatly beneficial for neurasthenia and excessive fatigue.

The darker the grape, the more flavonoids it contains, but if the grape skin and grape seeds are eaten together, the protective effect on the heart is even better.

Compared with other fruits, the diversity of grape products is much richer. Based on factors such as daily needs, storage and transportation requirements for processed products, and nutritional and health effects, people also process grapes into common products such as raisins, grape juice, grape seed beverages, and grape seed oil.