Q.Should I Prune/cut Off Lateral Branch In Tangerine Tree
Hi, we have a Tangerine tree (planted as a young tree 4 yrs ago). It is healthy & about 12 ft. High (red arrow shows height in pic). There is a very leafy branch (white arrow points to branch, in pic) that is pointing somewhat lateral & curving downwards (likely.due to weight of leaves). Should I cut off this branch from where it starts (see blue arrow in pic) to help the tree grow faster straight up? Or does it matter or not in an established Tree.

Certified GKH Gardening Expert
This will be the reason that it is the most common pruning. It is the healthiest method, though it is not the method for best fruit set. Pruning for best fruit set requires constant, proper pruning. For this reason, if you do not have a professional arborist to assist you, it is best to prune in the classic fashion to avoid losing the tree to disease.
Still, pruning that branch off is, completely, up to you.

Certified GKH Gardening Expert
This is normal for citrus of all types, and will be completely up to you on whether you remove it or not.
Many people prefer to trim up the bottom, for a more classic "tree" look. This has its benefits, as well. Trimming growth and expesing the trunk will reduce the chance for infection due to poor air circulation, as well as make the tree easier to maintain in the long run.
This article will help you to care for these trees: https://www.gardeningknowhow.com/edible/fruits/tangerine/tangerine-tree-care.htm

I am not so concerned about the classic. My aim is to have a healthy, growing & fruiting tree. Can you pls advise based on this?