Abstract:
Bulbs of 'Apeldoorn' lifted on june 13th were immediately stored for 1, 3 or 5 weeks at 30°C and then at 20°C or 15°C until the completion of flower differentiation, stage G. At stage G, bulbs were either planted at 14°–16°C or cooled at 5°C for 12 weeks before planting at 14°–16°C.
Extending from 1 to 5 weeks the 30°C treatment shortened the period necessary for flower bud completion, increased flower bud height at stage G, and had a favourable effect on subsequent rooting.
When bulbs were planted after a 12 week treatment at 5°C, extending the duration of the 30°C pre-treatment caused : faster rooting and better development of roots ; shorter period to flowering ; heavier aerial parts and decreased weight of the mother-bulb at anthesis.
Bulbs stored at 15°C during flower bud differentiation produced a large number of blasted flowers.
The results indicate that the degree of flower bud differentiation per se does not adequately define the physiological state of a bulb.
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