Q.
One hormone hastens maturity period in juvenile conifers, a second hormone controls xylem differentiation, while the third hormone increases the tolerance of plants to various stresses. They are respectively:
Spraying juvenile conifers with gibberellins hastens their maturity period, thus leading to early seed production. Auxin controls xylem differentiation. Abscisic acid (ABA) increases the tolerance of plants to various kinds of stresses, therefore, is also known as the stress hormone.