|Authors: ||L. Ehrich, H. Grüneberg, C. Ulrichs|
|Keywords: ||Babiana, Freesia, Sparaxis, Tritonia, inflorescence initiation|
South African Iridaceae contain many genera with a high potential for new floricultural crops.
From the beginning of 2005 until 2007, investigations on five geophytic species native to the Cape Floral Region have been conducted.
Belonging to the genera Babiana, Freesia, Sparaxis and Tritonia, they are winter growing and spring flowering in the Southern Hemisphere.
If forced as pot plants for the European autumn and winter months, their low temperature requirements during cultivation could represent substantial energy savings for the future grower.
The investigations focused on the following aspects: commercial availability in South Africa, export during the corm dormancy, storage conditions after export, forcing experiments at different times of the year in Berlin and general cultivation requirements of the different species.
The co-operation with New Plant Nursery in George, South Africa, which sells only species indigenous to South Africa, was essential in acquiring sufficient quantities of plant material to conduct adequate trials.
Results were obtained by regularly monitoring the corms and the plant development.
Inflorescence initiation was determined by microscopic examination of the shoot apical meristem during the growing season.
The export of dormant corms proved to be uncomplicated and their dormancy could be further maintained in subsequent storage in Berlin at temperatures above 20°C. Temperature was found to be the main criterion to successfully realise flowering after planting.
The species varied in their sensitivity, but generally cultivation at 13°C at night was essential, with temperatures of 17°C and above possible during the day.
During the Central European summer months, inflorescences in the terminal bud failed to completely develop or flower primordia were aborted within the corm due to the high temperatures present.
A reduction in plant height and enhanced flowering could be achieved for some species by specific storage regimes and the application of a growth regulator.
In conclusion, the investigated species/hybrids displayed a great potential for an energy saving production system as well as for enriching the autumn and winter pot plant assortment in Europe.
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