A
It induces the differentiation of new shoots from the rootstock
B
It frees axillary buds from apical dominance
C
The apical shoot grows faster after pruning
D
It releases wound hormones
The answer is B.
Solution
In most higher plants the growing apical bud inhibits the growth of the lateral (axillary) buds. This phenomenon is called apical dominance. It is caused by the auxin synthesised in the shoot apex, which moves downward and suppresses the lateral buds. In pruning, the shoot tips are cut off (decapitation), which removes the source of auxin. The axillary buds are thus freed from apical dominance and grow out into lateral branches. With repeated pruning more and more branches develop, and the hedge becomes dense and bushy. The same principle is used in tea plantations. So pruning makes the hedge dense because it frees the axillary buds from apical dominance.
ConceptApical dominance
Plant Growth and Development in past papers
85 questions from this chapter have appeared across 24 exam years.
