When did Jesus’ disciples begin to baptize?

Matthew and Mark: Not until after his resurrection (Matt. xxviii, 18, 19; Mark xvi, 15, 16).

John: At the beginning of his ministry. “After these things came Jesus and his disciples into the land of Judea; and there he tarried with them, and baptized” (iii, 22). “The Pharisees had heard that Jesus made and baptized more disciples than John. (Though Jesus himself baptized not, but his disciples.)” (iv, 1, 2).