Green light reduces the expansion of leaves.

Coumarin is a phenolic hormone.

It is a natural auxin known as auxin-b.

By adding auxin and sugar, continued growth of callus may be obtained and new shoots and even new plants can be produced from the callus.

Auxonometer is used to measure the growth of a plant.

Mica pieces were used by Boysen Jensen in his experiment.

2,4-D destroys broad leaved weeds and is used as a weedicide.

IAA is the universal natural auxin synthesised in shoot apices, leaf primordia and developing seeds from tryptophan.

Apical dominance is exhibited by auxins as their presence in the tip stimulates the growth of apical bud, but suppresses the growth of lateral buds.

Gibberellins function in both conversion of dwarf plants into normal plants and Parthenocarpic development of fruits.

Gibberellin was first isolated in 1935 in crystal form by Teijiro Yabuta and Sumuki, from fungal strains (Gibberella fujikuroi) provided by Kurosawa.

Cytokinins promote cell division.

Auxins inhibit abscission prior to formation of abscission layer. Thus, they inhibit senescence of leaves.

Abscisic acid causes dormancy of seeds.

Cytokinins never work alone. In the presence of auxins, they stimulate cell division.