‘These are some additional pictures.

I can't find the graft so I can't tell. The leaves look normal. Why do you still have a stake in there? At that size, it shouldn't be necessary.

Hey Denise thank you for checking it out, I also can’t tell if it’s grafted or not. I have the stake in place to help the tree stay straight it was crooked for a long time, and also I get some good winds being close to the coast here in south Florida.

The side branch leaves looks same to main so i cannot see any evidence it is rootstock. If you want a dual trunk tree then leave it. I'd cut that side branch if it were mine.

Its a common rookie mistake to let these side sucker branches grow. But i do believe trimming them promptly is the right thing to do. I have about 6 trees that i am trying to reshape due to letting the side suckers overtake the main. The reshape process is ugly (big cuts) and annoyingly difficult. Good luck!!

Thank you for the advise Molewackerz9b I have to make a big decision before spring on whether or not to cut the large side branch, I actually remember this year only the lower portion of the tree had flowering and fruit production.

Thank you for the advice esilviu I have gone back and looked at the pictures to look closely at the graft area I can see the difference in both branches, I definitely do not want the root stock to stunt the growth and production of my Navel Orange so I might have to plan on cutting it off before spring.

Cut the branch that does NOT have the ID tag on it.

Exactly poncirusguy thank you for the input I have to get on that as soon as possible.

The larger branch with thorns may also be a mutated sport, from my research this is more common in navel oranges than in other types of citrus. Cara Cara oranges are an example of a sport limb mutation that was found growing in a citrus grove in the 1970's, and have since been propagated.

Julian, you can air layer the larger branch up top at a point and make a new tree and grow it to see if it is a sport or not, you don't have to lose it altogether. In my opinion the larger side of the tree is a rootstock sucker and needs to be removed.

Sunshine zone 6a, thank you for the idea of air layering it. I am thinking it is a rootstock sucker and I might just have to cut off I am wondering if I should wait till spring or take care of it right away.

If you are really curious about the sucker, than make an air layer, if you don't care about it, just cut it off now and make a rolling pin out of it ( just joking:)), seal the wound though.

Sunshine zone 6a I am not too interested in the sucker if it isn’t the original Navel Orange tree, I rather invest the growth time into the main tree for better overall production. I have seen YouTube videos of the IV Organic paint nd tree guard but it’s not available in my local stores do you all recommend a good tree sealer? Thanks again for all the help.

Once you remove that large possible rootstock shoot, I think your Navel variety will really grow like gangbusters!

cut it off and place an upside down test tube over it

Steve

Thank you Steve for the very interesting idea to cover it with a can!

Thank you Dave In Nova! Let’s see what happens with my Navel Orange now hopefully it’ll do much better.