Did you get that from Fourwinds? It looks like a Cuban shaddock. Four winds used rooted cuttings of Cuban shaddock to graft to.

I did not i bpught it at OSH Now closed Can you explainn why first couple of years it fruited correctly - small orange dize fruit that turned orange over time

Also is it possible that it will go back to giving the regular sized bergamot oranges?

It sounds as if a branch(s) from the rootstock took over. You'll have to look for the grafting point to see if there is anything left of the original orange. If there is then you need to take off everything growing below the grafting point.

O my goodness! its a rather big tree now but i will check at least now i know thank you all

Post a picture of the tree trunk near the soil.

ya know.. if you want to have discussion about the plant.. one might suggest you post pix of the plant.. rather than just the fruit ...

maybe we can see where the understock overtook the graft .. its usually rather apparent ... once you know what to look for ..

ken

Here are the photos of the tree trunk. Correct me if I am wrong but it seems that the bergamot graft is completely gone and only remaining plant is the graft (cuban Shaddock).