PREVENTION OF UNWANTED FLOWERING OF ORNAMENTAL BROMELIACEAE BY GROWTH REGULATING CHEMICALS

Spontaneous flowering in Bromeliads occurs after the plants have reached a minimal size and "maturity" and during environmental conditions of much light after a relatively dark period and also following stress as a cold shock, transportation or repotting.
In commercial cultivation this phenomenon can cause great losses.

In order to investigate if prevention of unwanted flowering should be possible a lot of experiments with growth regulators and different light conditions were performed.
Only drastically lowering of the dayly light quantity seemed effective to a certain degree.

Recently we found that the biosynthesis of ethylene in a Bromeliad plant goes through the pathway methionine-SAM-ACC and there is a close relation with flowering induction.
We have tested some inhibitors of ethylene formation such as silverthiosulfate, amino-oxyacetic acid, and aminoethoxyvinylglycine (AVG). Of these AVG was the most active in greenhouse trials at very low concentration.
Treatment with solutions of 20 ppm or more resulted in phytotoxic side-effects as leave parts without chlorophyll which sometimes became necrotic.

With optimal fractionated application a retardation of flowering induction of three months and more could be realised.
On the other hand adverse effects on inflorescence development following ethephon spray two weeks after AVG-treatment were not noted.

Growth Regulators, XXI IHC

O. Mekers, M. De Proft, L. Jacobs

https://doi.org/10.17660/ActaHortic.1983.137.23