are orange trees grafted?

[speck-chaser]

My dad used to bud alot of orange trees using Trifolia. He would collect the oranges from them,plant the seeds, grow them in the field,and when they reached a certain size, would bud them with whatever orange he wanted. He had several big orange trees with up to 6 or 8 different kinds of fruit on them, that he had budded different oranges too. Like said previously, the trifolia root stock is used mainly because it is tough for cold and diseases. Many growers are starting to use lemon root stock, mainly because of its fast growth,and can produce a tree for sale much quicker, but will not withstand the cold as well as the trifolia root stocked ones. Orange trees can be grown from seed,but will take probably about 6-8 years before it matures enough to produce fruit. Hence the budding process speeds up the process. My dad had 800 mature trees at one time.