Standard salix could mean any Salix really, though the most common are Kilmarnock Willow and 'Hakuro-Nikishi', but need to know which one it is before giving a fuller answer.

By standard salix do you mean a clean stem with the branches at the top?
If it's a grafted plant any growth below the graft will be the same as the root stock, therefore you will need to remove this.
As Bamboo says, for a more in-depth answer, we need to know what type of willow it is.