Another factor in plant growth is the influence of plant hormones. Hormones are chemicals produced by plants that regulate their growth processes.
Plant growth regulators are chemicals applied to regulate plant growth; they are synthetic plant hormones. In plant propagation, cuttings are dipped in a rooting hormone to stimulate rootdevelopment. In greenhouse production, many potted flowering plants (like poinsettias and Easter liliestreated) may be treated with plant growth regulators to keep them short. Seedless grapes are treatedwith plant growth regulators to increase the size of the fruit. in certain situations, turf may be treated to slow growth and mitigate the need for mowing. Some plant growth regulators are expensive, labor-intensive, and have little application in home gardening. Others are commonly used, including many herbicides.
Hormones are produced naturally by plants, while plant growth regulators are applied to plants by humans. Plant hormones and growth regulators are chemicals that affect:
- Flowering.
- Aging.
- Root growth.
- Distortion and killing of organs.
- Prevention or promotion of stem elongation.
- Color enhancement of fruit.
- Prevention of leafing, leaf fall, or both.
- Many other conditions.