Question 8
About three weeks after a bud graft, the stem of the stock is cut away roughly 15 cm above the grafted place. Why?
The right answer is the one marked above.
So that everything the roots send up goes into the one grafted bud. The new bud then grows well.
The timing is the point of the question. Cut too early and the bud is not yet established enough to use what the roots send; the three weeks are spent waiting until it has visibly taken. The wrapping is loosened far earlier, as soon as the bud starts growing green.