[mdjlucan]

I’ve got a blueberry bush, which is about a year hold now. I’ve noticed that I’ve got a thick branch coming out from the bottom of it it’s straight stem and it’s taller than the bush

[Nobbie]

Yes, they do that. I’d just leave it.

[Snow]

It'll be a fruiting stem in later  years. Typically you can get a fruiting stem to be productive for about 6 years with decent pruning , then it's usually best to chop the whole stem off as it tends to get a bit twiggy and unproductive.  Blueberries can be really productive for 50 years with proper pruning. It should put out at least one or two new stems each year