Detailed Explanation of the Latest Breeding Methods for Grafted Citrus Seedlings

Citrus is widely cultivated in the south, with a great many varieties, and it is an important source of income for farmers in many regions. The propagation and seedling methods for citrus include grafting, seedling growing, cuttings, layering, and others. Generally, in actual production, these methods are often used, and the following will mainly introduce the propagation of grafted seedlings and how to carry it out.

1. Time for Raising Seedlings

Grafting is carried out in spring, when the survival rate is relatively high, because the weather, temperature and humidity are suitable at this time for both the rootstock and the scion. Of course, it can also be done during the cool autumn "little Indian summer," but the survival rate is somewhat lower.

2. Preparations for Grafting

For rootstock, sour pomelo, fragrant orange, trifoliate orange and others can generally be used, but at present trifoliate orange is mainly used. This is because trifoliate orange has extremely strong cold resistance and relatively strong adaptability and disease resistance. Therefore, it is necessary to buy enough rootstock seedlings in advance, or dig up wild trifoliate orange seedlings. Trifoliate orange or other rootstock seedlings can be grown in large quantities at home for use. For the scion, healthy and strong mother plants should be selected, and 10 to 15 cm healthy one- or two-year-old twigs should be taken, with enough plump buds on the branches. Cut off the branches and remove the leaves.

3. Grafting Methods

After preparations are complete, first cut the rootstock short at 5 cm above the ground, then leave one cut surface. On the epidermal layer of the cut surface, cut downward about 2 cm along the phloem, then make one cut at the bottom of the scion to produce a smooth slanted surface 1.5 cm long. Then insert the scion into the bark layer of the rootstock, with the slanted surface pressed tightly against the rootstock. Finally, wrap it round and round with transparent tape or plastic film, generally with suitable tightness, and it is best to leave room for growth. The whole process must be done quickly, and after about half a month the survival can be checked. If the scion withers, the grafting was unsuccessful. If it was unsuccessful, it can be regrafted in time by making a cut on the other side of the rootstock and selecting a new scion. However, seedlings after regrafting can be given special care. Generally, grafted seedlings must be planted in shaded land, covered with shade netting, and watered frequently to keep them moist. Then, after normal growth, they are transplanted, generally after one to two months. The transplanting site needs sufficient base fertilizer and thorough watering. Pesticides should be applied well to prevent and control diseases.

Compared with other propagation methods, grafted seedlings are a relatively superior propagation method, because they can make good use of the superior qualities of the rootstock, such as disease resistance and adaptability, to make up for the shortcomings of the scion variety and change the plant's advantages and growing conditions, so this method is often used in production.