2009 Volume 8 Issue 4 Pages 483-487
The effects of low temperature treatment of cuttings, including potted cuttings, on growth and flowering of Hypericum andorosaemum L. ‘Excellent Flair’ were examined. Potted cuttings were exposed to ambient temperature from October 15, 2004 to March 9, 2005. These were repotted in 12 cm-plastic pots and grown under long day conditions in a greenhouse at a minimum temperature of 15°C. The number of nodes of the lateral branch at anthesis of the first floret and days to flowering were increased compared to those of controls treated at ambient temperature. Cuttings were treated under low temperature conditions at 2.5, 5 or 10°C for 0, 1, 2, 5 or 7 weeks. The number of roots increased when treated at 5°C or less that after for 5 weeks and days to flowering were reduced when treated at 5°C for 5 or 7 weeks, compared with the other treatments. Potted cuttings were treated at 2.5, 5, 10 or 15°C for 1, 3, 5 or 7 weeks, or were untreated (control), remaining in the greenhouse for the entire experimental period. Days to flowering of plants treated at 2.5°C for 7 weeks or 5°C for 5 or 7 weeks and the number of nodes on the lateral branch at flowering were reduced after treatment at 5°C for 5 weeks compared to that of controls or those receiving other treatments. Based on the above findings low temperature treatment of cuttings increased the number of roots cuttings and reduced the days to flowering in Hypericum ‘Excellent Flair’.
