Hi Lali,

Can you post a pic of the whole tree? and a close up of the leaves on what you believe to be suckers and a close up of the leaves on one of the fruiting branches.

Its easy to get confused over grafts and graft lines. A graft line isn't always so many inches above the soil - mine certainly differ. You are looking for 'scarring' where they have been grafted, or a diagonal offshoot - where the rootstock grows straight up, then a branch veers in a slightly different direction than straight up.

Can you give a little more info on how you care for the tree? well draining soil, watering habits, fertilizer, sunlight etc. If suckers arent to blame it could be something else that is missing. If suckers were taking over, I believe they would have done it by now and you would not have the tree you want still growing, and since you have fruit on the tree, it might not be a suckers problem

Lali, in the first pic, I think I see the graft, but not certain..The middle trunk has a small bump..to the right of the bump is a small branch, (probably a sucker) growing.
Remove the small branch, and anything growing below. Suckers are thorny. Thorns can grow a couple inches long.
Toni

I'll try to post more pics of the tree soon.

As for the care of the tree, we have well draining soil (soil is a bit sandy), it gets full sun all day all year, I water a few times each week in the summer making sure to let the soil dry a bit and maybe once a week in other seasons. I fertilize using organic avocado/citrus fertilizer from Armstrong Gardens once every 3 months as recommended by the nursery people there.

I'll definitely look out for the branches with lots of thorns. I do notice a difference in leaf patters on some branches though. The branches that have fruit have leaves that are more spaced out, not clustered at all. Some branches have clustered leaves (2-4 leaves) growing in the same general area at a time and tend to be a lot bushier. I'm not sure if it's just the habit of the tree to have these differences or not, so I haven't cut anything away yet.

Like I said I'll try to post more pics soon. Maybe that will provide a little more information.

TIA!
Lali

Yeah more pics would be great :) Really search for any sign of a graft. If the little side shoots you see are quite high up, they are likely a part of the wanted citrus, not the rootstock. It can be tempting sometimes to discover a possible problem and stick with it, so just be careful not to start cutting until you know for definite. If it was a graft, it would probably be easy to find, with a scar or, like hopefulauthor stated, a bump.

One thing to be wary of is fertilizer. Make sure you don't fertilize too much. On the second pic, a few of the leaves have yellowing tips. If they go dry, this is a sign of too much fertilizer. Does the one you are using have trace minerals in it? eg iron, magnese, copper, boron etc. Those yellowing bits can be a sign of mineral deficiency, which could stunt the plants growth and prevent it from fruiting and flowering as it should.