why is a sacrifice branch so important?

[jme]

I see a lot of people leaving a sacrifice branch (I think that's what it's called)
They let it grow untouched and then just cut it off later down the track. Why is this important?

[EdwardH]

The purpose of a sacrifice branch is to thicken the trunk, so the lower down thr trunk, the better the results.

[Bougy Fan]

It is best to have the sacrifce at the back as there will be a scar when it is removed. Also note the trunk thickens below the branch so not too low. You can use a branch for so long and then start another. The trunk will eventually thicken with a "lump" where the branch is and become unsightly.