u/Careless-Day1854

I bought a Home Depot Meyer lemon but I think it has a rootstock sucker growing from it and wanted to get a second opinion.

The tree has two main stems. The taller upright stem has normal leaves and almost no thorns, but the lower side stem coming from near the base has long thorns (around 1 inch) and seems more aggressive/vigorous.

From what I’ve read, it sounds like the thorny growth may be rootstock growth below the graft union. Does that look correct to you guys? Should I remove it completely?

(Photo attached)