Why do pre-pruning?
Pre-pruning consists of going through the vines early with a pre-pruner to trim the shoots to a specific height.
This saves time when pruning and especially when pulling the branches off the wires after pruning, since the branches come off more easily and are shorter.
The time saved is particularly significant for short cordon pruning (up to 60% faster) but less so for Guyot pruning (up to 10 - 15%). If the vines are braided, this technique can considerably simplify the task, as braiding tends to make the removal of cut branches more difficult, as the upper parts are intertwined.