Table 1.
Overview of the different treatments with start date, duration, day length, and mean DLI for Rhododendron simsii ‘Nordlicht’ and R. simsii ‘Sachsenstern’.
| ‘Nordlicht’ | ‘Sachsenstern’ | |||||||
|---|---|---|---|---|---|---|---|---|
| Treatment | Start date | Duration (days) | Day length (h) | DLI (mol m-2 d-1) | Start date | Duration (days) | Day length (h) | DLI (mol m-2 d-1) |
| Cold | 29/09/2010 | 35 | 0 | 0 | 13/10/2010 | 49 | 0 | 0 |
| F | 02/11/2010 | 653 | Natural (8.5)2 | 1.3 ± 0.8 | 30/11/2010 | 833 | Natural (8.1) 2 | 1.4 ± 1.1 |
| First week F 1 | 02/11/2010 | 7 | Natural (9.5)2 | 2.5 ± 0.7 | 30/11/2010 | 7 | Natural (8.2) 2 | 0.9 ± 0.4 |
| FA | 02/11/2010 | 653 | 16 | 5.2 ± 0.8 | 30/11/2010 | 633 | 16 | 5.2 ± 0.8 |
| FAL | 26/11/2010 | 424 | 18 | 0.7 | 29/12/2010 | 414 | 18 | 0.7 |
Cold treatment consisted of five (‘Nordlicht’) or seven (‘Sachsenstern’) weeks at 7°C in dark conditions. Light conditions during flowering were: forcing at natural light conditions (F), forcing at optimal light conditions with 16 h supplemental light (SON-T, 75–80 μmol m-2 s-1 at plant canopy level) (FA), and post-production flowering (FAL) where FA plants with CS were placed in a growth chamber under controlled conditions mimicking growing conditions similar to those in the consumer’s home (19.8 ± 0.4°C, 73.7 ± 9.5% RH, and 18 h light at 11 μmol m-2 s-1). 1First week F: this row provides information on the light conditions during the first week of forcing at natural light conditions. 2Average natural day length during the forcing period. 3The number of days between the start of forcing and the end of measurements to assess the quality of flowering. 4The number of days in the growth chamber until the end of measurements to assess the quality of flowering.