Effect of Low Temperature on the Flowering of Stock
Chang, Y. T., S. S. Wang, D. L. Lin, Y. C. Wang and C. S. Chang
This experiment was attempted evaluate the possibility of growing stock in Taiwan and to invested the effect of low temperature on it’s flowering performance. Nineteen commercial cultivars were planted in the winter. All cultivars, except the late flowering ones, were able to flower normally. The extremely early cultivars bloomed first followed by the early ones were. However, their spike length was shorter. Early flowering cultivars were bloomed a little bit lately, the floral spike length was longer and the quality was also better. Four commercial cultivars’ Early red’, ’Magic white No.2’, ‘Yellow wave’ and ‘Lately beauty’, after seed germination, were planted in the plug trays and subjected to a 12-hr dual temperature range at 15/10℃ (day/night) for 2-4 weeks at a week interval, and then they were grown in the greenhouse, non-treated plants served as control. All the treated plants flowered earlier and they were found with longer spike. The effect of low temperature was most promident in the extremely early and early flowering cultivars. Four commercial cultivars ’Early red’, ’Fall red’, ‘Early blue’ and ‘Snow wave’, potted and plugged seedlings were also subjected separately to the low temperature at 10℃ for 3-5 weeks at weekly interval. The potted seedlings bloomed one week earlier. Low temperature for 4 weeks was the best treatments that have higher plant and longer flower cluster.
Key words: Stock, Vernalization, Cooling
Accepted for publication: 13 February, 2003