Temperature regime during bulb production affects foliage and flower quality of cv. Ronina pot plants

Flowering-sized bulbs of Lachenalia that developed under three different temperature regimes [S. Afr. J. Plant Soil 18 (1) (2001a) 28] were used to assess the quality of subsequent pot plants. Plants were grown in a growth cabinet at a 15/10°C day/night temperature regime. When the oldest flower of the inflorescences opened, the pot plants were transferred to a growth cabinet that provided a constant temperature of 22°C with lower lighting conditions to simulate office conditions. The flowering date, keeping ability as well as the morphology of the inflorescences were evaluated. After the senescence of the inflorescences, the plants were harvested and dissected into different plant parts for evaluation. The temperature pre-treatments had a major effect on the performance of the subsequent pot plants. Flowering occurred 8 weeks earlier compared to plants normally grown in outdoor conditions in the Pretoria region (summer rainfall area). Furthermore, the low temperature regime (LTR) treated bulbs produced inflorescences with the longest keeping ability and simultaneous flowering was noticed. The lower the temperature regime during the bulb production phase, the greater is the peduncle length, rachis length, floret number as well as the peduncle diameter of the primary, secondary and tertiary inflorescences.