G. H. Pemberton, A.A. De Hertogh
Fifteen commercially available Astilbe x arendsii cultivars were used in several trials to study growth and development and flowering. Single-eyed crowns were used in all experiments. Crowns harvested in early October in 1990 were physiologically immature compared to those harvested in early November in 1991. Immature crowns had a lower resistance to insect and disease attacks. These physiologically immature crowns were also more susceptible to flower abortion not only during cold-storage but also in the greenhouse. Astilbe floral development was studied using scanning electron microscopy. Upon arrival multi-flowered inflorescences were visible. During storage, Astilbe crowns continuously reinitiated reproductive meristems when previously formed ones aborted and decayed. Some cultivars were more prone to abort their flowers during storage than others. The cold-week requirements for flowering were cultivar dependent. Astilbes forced at 26°C Day (D)/22°C Night (N) had a higher number of aborted flowers than those forced at 18°C/14°C (DN) and 22°C/18°C (DN). Long days promoted flowering in astilbes, while short days partially inhibited it.
Pemberton, G. H. and De Hertogh, A.A. (1992). FLORAL DEVELOPMENT OF ASTILBE X ARENDSII. Acta Hortic. 325, 229-234
DOI: 10.17660/ActaHortic.1992.325.27

Acta Horticulturae