Effects of exposure of bulbs to high temperature oa flowering of Allium cowanii Lindl.

The effect of exposing bulbs to high temperatures just after harvest on the flower-bud initiation and development in Allium cowanii was examined. Bulb s, stored at various temperatures under dry conditions were potted in early October and grown in a greenhouse kept above 10 degrees C. 1. Bulbs which were harvested from plants grown the previous season in an u nheated plastic house and thereafter stored in the same house for 2 months, flowered 27 days earlier than those harvested from plants grown outdoors a nd stored in a shed. 2. When bulbs were exposed to 25 or 30 degrees C for various periods and st ored at 9 degrees C for 3 months, those exposed to 25 or 30 degrees C for m ore than 12 or 4 weeks, respectively, initiated inflorescences. 3. When bulbs were exposed to 25, 30, 35 or 35/25 degrees C (day/night) for 8 weeks from early May, followed by storage at 25 degrees C for 3 months, those stored at 30 and 35 degrees C produced 3 inflorescences per plant dur ing December. Bulbs which were exposed to 30 degrees C for 0, 4, 8 and 12 w eeks, followed by the storage at 25 degrees C for 3 months, flowered at dif ferent times; those stored for 4 or 8 weeks flowered the earliest. 4. Bulbs stored at 30 degrees C for 8 weeks, at 25 degrees C for 2 months, and at 20 degrees C For 1 month from early May flowered in mid-December and produced 3 inflorescences successively.