How do you carry out autumn top-grafting to change citrus varieties? Latest technical method tutorial
Citrus top-grafting to change varieties means grafting improved, high-quality varieties onto the branches of the original old citrus variety. This renews the variety of the citrus tree, improves the quality of the citrus tree and promotes fruiting. If the top-grafting variety change work is handled properly, then in the same year it can survive, in the second year it grows a canopy, and in the third year it can begin to bear fruit. So how should citrus top-grafting to change varieties be carried out? Let's take a look together below!
1. Preparation for top-grafting
Before carrying out top-grafting to change varieties, we must first determine the timing of the top-grafting, and then make preparations for it. The top-grafting time for citrus should be chosen after the annual summer drought ends and after the autumn shoots have matured, generally in August-September. Two weeks before grafting, we should strengthen the management of the trees to be changed. Carry out one round of mid-cultivation and weeding, control the amount of water and fertilizer well, promote the growth of the trees to be changed, improve the survival rate of grafting, and avoid grafting failure that affects planting returns.
⟦NL>2. Top-grafting method
First we should thin out the overly dense and tangled large branches on the trees to be changed. Keep some small inner-canopy twigs on the lower part of the canopy, and cultivate them as auxiliary nourishing branches. Then, according to various factors such as tree age and canopy, carry out multi-head top-grafting. Young trees are generally grafted with about 15 buds, young-mature trees can be grafted with 50, and mature trees can be grafted with about 90 according to the actual situation. Make sure the grafted buds are evenly distributed on the tree, and the distribution branches should mainly be upright branches and slanting branches.
Before carrying out top-grafting, first choose a diamond-shaped scion, then cut it into a single bud. Then make an opening on the branch, cutting through the cortex straight to the xylem, with the cut kept at about 3 cm. Then place the grafted bud into the rootstock, fix and press it tightly to ensure the grafted bud and rootstock unite. Then bind the graft union tightly with grafting film. Do the post-grafting management work well to promote and avoid air leakage and water leakage, which would affect the survival rate of grafting.
3. Post-grafting management
About three weeks after grafting, we should frequently check the grafting condition of the grafted buds and determine whether the graft union has survived. If the grafted buds are found to be withered and yellow, moldy, or otherwise wrongly colored, then the grafting has very likely failed. Therefore at this time, we must finish the re-grafting work before the end of October. If the color of the grafted buds is normal, then it means the grafting has succeeded. However, note that at this time the grafting film must not be untied, otherwise it will seriously affect the growth of the new shoots, and freezing damage and other conditions may occur and cause death. The film should be removed in stages before Qingming Festival of the following year.
The above is a brief introduction to the autumn top-grafting variety-change technique for citrus. Top-grafting to change varieties can effectively increase citrus yield and fruit quality and enhance planting returns, so everyone must pay close attention. That is all for today's introduction; friends who want to learn more related information, please continue to follow us!