ISHS Acta Horticulturae 305: First European Workshop on Thermogenesis and Photomorphogenesis in the Cultivation of Ornamentals
PREFACE |
| Authors: | T. Blacquière, M. Zande, J. Vogelezang |
| DOI: | 10.17660/ActaHortic.1992.305.0 |
| Abstract:
In horticultural practice, there exists an important need for tools to control growth, especially elongation growth, of ornamental crops. Generally, the aim is to reduce elongation, in order to produce compact and easy to handle plants (pot plants and bedding plants), or to get firmer stems for cut flowers, reached by more weight per unit stem length (Chrysanthemum). Until now most of this "growth regulation" occurs by use of chemical growth retardants, chemical compounds that often interfere with the biosynthesis or metabolism of gibberellins in the plant. However, in many countries the use of chemical growth retardants is seriously in debate now, because of legislation for preservation of the environment. Elongation growth of plants can also be manipulated by other means, such as nutrition, water supply (drought), relative air humidity, temperature and light (photoperiod and light quality). The latter two, temperature and light, show a lot of homology (Moe and Heins, 1990, Acta Hort. 272, 81–89), and have in common with chemical growth retardants that they interfere with gibberellin synthesis and/or sensitivity, and can be applied without significant reduction of crop growth rates. Therefore "Thermomorphogenesis" and "Photomorphogenesis" were the subjects of a workshop, held in Aalsmeer (Netherlands) in November 1990. In addition to scientific discussions and exchange of knowledge, the workshop also aimed to stimulate future exchange and research cooperation, in order to avoid duplication, and to make optimal use of the different facilities available at the different places in Europe. A second workshop on the same topics will be held in Ås (Norway) in 1992. Several of the papers in this issue have been refereed, to improve their quality, some others have not, because they describe preliminary results or review earlier work, published elsewhere. We hope that, together with the other approaches mentioned, temperature and light control will replace (partly) the use of chemical growth regulators. | |
