AUXINS (IBA, …)
- Auxins are known to activate cell elongation by increasing the level of elasticity of the cell walls.
- Auxins stimulate ethylene production and inhibit the growth of buds. This effect is known as apical dominance.
- They also promote adventitious and lateral root growth and development.
- Auxins include 3-Indoleacetic acid (IAA), 3-Indolebutyric acid (IBA); 1-Naphthylacetic acid (NAA) among others.
CYTOKININS (KINETIN, …)
- Kinetin is the only Canadian registered cytokinin that can be used on a variety of crop species.
- Kinetin is considered a “green” plant growth regulator.
- Kinetin increases the rate of cell division, differentiation and growth.
- It delays senescence in plant tissues, increases ﬂower set, fruit formation and side branching.
- Kinetin also increases ﬂower set, fruit formation and side branching.
- 2 effects depending on application timing:
- Early (3-5 leaf stage): increases the number of seeds per kernel/pod
- Late (during reproductive stage & prior to grain fill): increases the Thousand Kernel Weight (TKW) and seed size
GIBBERELLINS (GA3, …)
- GA enables seed to overcome dormancy and promote the activity of the a-amylase, sprouting and emergence.
- GA affects cell elongation.
- GA can increase seed and fruit set when applied appropriately.
- Ethylene aka the senescence and ripening PGR.
- Abscisic acid aka dormin or dormic acid that encourages dormancy and controls stomata opening and water-use efficiency under stress conditions.
- Brassinosteroids involved during the reproductive stage of certain plant species.