Growth Substances and Their Functions

Growth Substances and Their Functions

Sl. No	Hormones	Functions
1	Auxin	Named by F.W. Went. It has apical bud dominance, inhibits root elongation and promotes cell division in tissue culture.
1a	IAA	Prevents premature fruit drop.
1b	IBA	Root formation
1c	NAA	Fruit thinner, prevents fruit drop.
2	2,4-D	Fruit setting hormone (< 20 ppm) and also used as herbicide (> 20 ppm).
3	Cytokinin	Dormancy breaker, stimulates cell division.
4	Gibberellins	Cell elongation, increases fruit size.
5	Abscisic Acid (ABA)	Induces dormancy, stomata closer, also called anti-gibberellin.
6	Ethylene	Ripening of fruits, Isodiametric growth of stem & roots.
7	Chlormequat (CCC)	Lodging preventor, also known as cycocel.
8	Maleic Hydrazide	Growth retardant, prevents onion sprouting in storage, sold under trade name Sprout Stop.
9	Ethephone	Trade Name – Ethrel, used as banana fruit ripener.
10	Glyphosate	Used as sugarcane ripener.