What are the common bud grafting methods for citrus? How to do it?

The methods of citrus grafting can be divided into three types: budding, ventral grafting and cutting grafting. Spring splicing is mostly used in the south subtropics with higher temperature, while bud grafting or multiple grafting is mostly used in the middle subtropics and the north in autumn. Citrus bud grafting has "T" bud grafting and inverted "⊥" bud grafting, the two methods are used everywhere, and the suitable grafting period is from mid-August to mid-October. The scion is fully ripe at this time. The sap flow of rootstock is also very exuberant, the peeling is easy, and the survival rate of grafting is high. Choose a smooth and straight place where the rootstock is 15 cm from the ground, cut a knife horizontally and vertically from the center of the transverse incision with a knife tip of about 2 cm, and use the knife tip to lift the cortex of the longitudinal cut of the rootstock to both sides. When cutting buds, generally put the branches smoothly (or upside down) in the left hand, clamp with the thumb and index finger, hold the knife with the right thumb and index finger, cut the bud slice from 0.5 cm below the bud, stop at 0.7 cm above the bud, pull out the blade, and cut off 45 °at the knife stop place, you can get a boat-shaped bud piece with xylem under the bud point, with a bud length of 1.2 cm. The standard bud piece should take the bud and petiole as the center, and the length of the upper part and the lower part of the bud should account for 2 to 5 and 3 to 5 respectively. The cutting surface of the bud should be smooth and hairless. When inserting buds, hold the buds with your right hand, insert the lower end of the buds into the horizontal incision of the rootstock, push down hard, so that the whole bud is smoothly inserted into the longitudinal incision, until the upper end of the bud is closely connected with the "T"-shaped transverse incision of the rootstock. Then use a 1cm wide, 20cm 25cm long thin film strip, first bind the buds tightly, the left side length 1max 4, the right side length 3cm 4, then wrap the right film strip down 2 times, then up 2-3 times, 1-1.5 cm knots on the bud mouth can be tied up. "T" bud grafting and inverted "⊥" bud grafting under the knife, rootstock incision and bud insertion entrance are just the opposite, other operations are exactly the same, and there is no difference in grafting survival rate.