|Author: ||A. H. Halevy|
The use of plant bioregulators (PBRs) in ornamental crops is more prevalent than in edible crops.
The most common types of regulators used are gibberellins (GAs, most often GA3), ethylene and their antagonists.
GAs are used to enhance elongation of many cut flowers and to promote bud break, thus producing more flowering shoots.
They are commonly used to promote flowering of long day (LD) and cold requiring plants grown under marginal inductive conditions and of autonomous-flowering plants of the Araceae.
GA also enhance postharvest life of certain flowers and foliage plants.
The main use of ethylene in ornamentals is to promote flower formation, especially in bromaliads and certain bulbous plants.
When desired, ethylene also promotes lateral branching.
The largest use of bioregulators in ornamental crops is probably that of GA antagonists - the growth retardants.
They are commonly used in pot plant production to achieve more compact and attractive structure they promote flowering in certain woody ornamentals.
Endogenous and external ethylene is the main factor reducing post-production life and promoting flower and foliage abscission of many ornamentals.
Silver-thio-sulphate (STS) is the main ethylene antagonist used to protect plants from ethylene damage.
Concern about the impact of STS on the environment has promoted a search for effective alternatives.
Those presently available, however, are less effective than STS. An effective chemical may be a volatile ethylene binding-site inhibitor such as diazocyclopentadiene.
Manipulation of cytosolic Ca2+ level may become a novel means for controlling flowering, flower senescence and geotropic bending of flowers.
Download Adobe Acrobat Reader (free software to read PDF files)
URL www.actahort.org Hosted by KU Leuven