2018 Volume 17 Issue 1 Pages 73-78
We investigated that effect of intermittent low-temperature storage on flowering acceleration and growth of Begonia × hiemalis ‘Netja’. The experiments were conducted from early August to early September in 2012 and 2013 under 50% shading in a greenhouse and refrigerator with the seedlings grown in 7.5-cm pots in diameter. The average temperature of the greenhouse ranged from 23 to 32°C, and the day length ranged from 12 hours 37 minutes to 13 hours 57 minutes. The first node number with a flower cluster of 2D/2D × 8 (processing of two-day refrigeration treatment at 10°C in the dark followed by two days under greenhouse conditions was repeated for eight cycles) and 4D/4D × 4 was decreased compared with that of plants grown only under greenhouse conditions (control). The timing of flowering of 2D/2D × 8 and 4D/4D × 4 was 3 to 14 days earlier than that of the control. In 4D/4D × 4, the first node number and timing of flowering of 10, 12.5, and 15°C refrigeration temperatures was significantly decreased compared with that of the control. Flowering timing accelerated as the refrigeration temperature increased from 10 to 15°C. Plant height at 10 and 12.5°C was more inhibited than that of the control. However, treatment at 15°C tended to cause spindly growth. In conclusion, we recommend 4D/4D × 4 at 10 and 12.5°C refrigeration temperatures as the timing of flowering significantly accelerated and potted plant quality was as good as the control plants.
