Detailed Explanation of Key Techniques for Ginkgo Seedling Rootstock Grafting Propagation

Seedling rootstock grafting propagation is a new technique developed in recent years. Compared with ordinary grafting methods, it shortens the nursery period by one year, has a high survival rate, produces good-quality seedlings, and costs less. Below is a share of the key techniques for ginkgo seedling rootstock grafting propagation, for reference.

1. First germinate the seeds indoors. Sow the germinated seeds in nutrient pots, placing 1 seed in each pot of soil. The seed should be placed on its side so that the radicle grows downward and the hypocotyl grows upward without bending, making grafting easier. Cover with an appropriate amount of nutrient soil, then place the nutrient pots in a greenhouse.

2. Before the seedlings emerge, keep the temperature at 25—30℃; after the seedlings emerge, keep the temperature at 20-25℃, increase light, and promote thickening growth of roots and stems. When the embryo bud grows to 3 cm and the first pair of true leaves is about to unfold, it can be used for seedling rootstock grafting.

3. In mid-March, before the buds sprout, collect 1—2-year-old branches with plump young buds and a thickness of 0.3—0.4 cm from superior, robust, mature mother trees that have already fruited. Wrap them in plastic film and store them moist at a low temperature of 0-2℃ in a cold storage or refrigerator to keep them fresh. When the young buds of the rootstock seeds are about to unfold true leaves, lift the seedlings for grafting.

4. Cut off the rootstock sprout about 3 cm above the cotyledon petiole, and make a 2 cm cut along the cotyledon petiole and along the center of the embryo stem. Carve the lower part of the scion into a wedge shape, with both cut surfaces 1.5 cm long, and keep 1-2 buds on the upper part. Insert the carved scion into the cut, then tie it firmly with plastic tape and keep it in the greenhouse. Because the rootstock is young and tender and the scion is short and small, healing is relatively slow, so spray warm water once every morning and evening. Keep the greenhouse temperature at 20-25℃ and relative humidity at 80%. After about 25—30 days, the scion and seedling rootstock heal well, and the scion begins to sprout.

5. After survival, loosen the binding in time. After leaf unfolding, over 15-20 days, cut off the kraft paper or agricultural film, and plant out in the nursery at a spacing of 40 cm×20 cm, with 50%-60% shade, which is removed in late August.

6. Grafted seedlings can bear fruit 3—4 years after planting out, and they maintain the excellent characteristics of the scion, with excellent traits such as fast growth, high yield, and easy cultivation.

The above is a summary of the new grafting technique for reference only. For specific implementation, it is still recommended to consult the local agricultural machinery department in detail.

In addition, ginkgo propagation methods include transplanting root-sucker seedlings and sowing seeds to raise seedlings. After the Spring Festival and before Qingming, root-sucker seedlings can be dug up and planted out, with more fine roots retained; it is not suitable to water heavily. The method is simple, the survival rate is high, and growth is fast. For large-scale cultivation, sowing seeds to raise seedlings is needed, preferably by spring sowing, mostly using the drill sowing method.