Esperienze Di Estivazione Su Urginea Maritima Bak.

Aestivation experiments on URGINEA MARITIMA Bak. — Bulbs of Urginea maritima Bak. have been subjected to artificial aestivation in different months (March, April, May, June) in order to find out the most appropriate period for forced blossoming. The bulbs, once taken out of the soil, have been kept for a whole month at 28° C, with atmospheric humidity not strictly controlled but never falling below 48%.Aestivation in March and April, when the plant is in its full vegetative activity, caused suppression of the sexual phase. Aestivation in May, when the vegetative activity of the plant is approaching its end, caused total flowering anticipated of about 20 days. Aestivation in June, when the plant is at the beginning of its resting period, had no effect on flowering.These results seem to show that the leaves create in the course of their activity the necessary conditions for flowering and that this critical stage is reached, in the plants under examination, between April and May.In the plants treated in May that is after they had reached the critical stage, the flowering was not suppressed; on the contrary it occurred earlier than in the plants left in their natural habitat. The advancement of the time of flowering corresponded more or less to the anticipation of the artificial as compared with the naturally occurring aestivation.