Why would you want to graft a citrus tree?
Grafting (including any method of budding) can give a tree several advantages:
1. Oranges and grapefruit are highly susceptible to foot rot disease, caused by Phytophthora citropthora and P. nicotiana. Some rootstocks offer considerable resistance to that disease. So on infested land, its important to use such a stock.
2. Rootstock variety has some effect on the strength of flavor of the fruit, the sweetness, total yield of the tree, and cold-hardiness of the tree.
3. Some rootstocks have resistance to certain virus diseases, nematodes, or other problems.
4. Some citrus scion varieties are difficult to root from cuttings. Grafting is a convenient way to reproduce such trees, since virtually all citrus varieties are very easy to graft. A grafted tree using a mature scion will not have the years of juvenility that a seedling would have.
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