Plant Growth Regulators
Plant Growth Regulators (PGRs) are applied to the plant to influence the development and growth of the plant. This includes grass, where PGRs can be used to decrease the amount of mowing required. Some regulators will speed up growth, whereas others will slow down growth. Many growers use regulators to slow down growth to ensure plants do not become elongated. Plants can get so tall they fall over under their own weight and then can't be harvested. So reducing overall height with a PGR can save crops. They can also be used to keep the crop uniform in size.
Plant growth regulators can be used on amenity grass and golf courses to reduce the need to mow as frequently. The most obvious amenity examples are to improve bowling greens and golf courses.
The use of regulators will also help prevent lodging (where crops ‘fall over’ due to having too much height) which will in turn increase crop yield.
Some ideas for PGR use include:
- As a branching agent to create a bushier potted plant.
- To reduce the number of times you need to mow the grass.
- Slowing the growth rate of a plant to keep it healthier with a growth retardant.
- Using a specific PGR to enhance flower production.
- Reducing the need to prune ground cover or shrubs with a growth retardant.
- Increasing fruit size with a Gibberellin PGR.
How and when to apply PGRs will vary depending on the type, the plant, and the purpose.
Charles Darwin discovered the first plant growth regulators. The first phytohormone to be discovered is the Auxin and it was discovered by the biologist Charles Darwin. Auxins are one of the most important plant hormones. The chief naturally occurring auxin is indole-3 acetic acid – IAA and other related compounds.