One of the most critical times to prune is early in the branch’s history. Failure to prune early will result in a weak root system, which can cause the branches to become a tangled web of foliage unable to produce enough sap to bear fruit. If not pruned, a branch will eventually die a premature death. But if pruned carefully, though, its life span and fruitfulness dramatically increases.
A typical young branch will surface ten to twelve buds that can become clusters of grapes. But early on, it will need to be pruned back to two or three buds, in order to product rich, luscious clusters of grapes. Two or three luscious clusters is preferable to ten or twelve mediocre clusters. Interestingly, the gardener is never closer to the branch than when he is pruning it. Each branch is unique, so each branch needs to be carefully analyzed in order to be pruned most effectively. The gardener scrutinizes each branch, because he knows than an abundant harvest is at stake.
Dann Spader, 4 Chair Discipling, p 118-119.