PERIODICAL DEVELOPMENT OF HYACINTHOIDES-H ISPANICUS (MILL) ROTHM

Hyacinthoides hispanicus is one of those geophytes which initiate and develop inflorescences after wilting of leaves during a period of high er temperatures. After 12 weeks of dry storage inflorescences were wel l developed at 11 degrees C or 17 degrees C, while commercially or at 5 degrees C stored bulbs produced scapes of only half the length. Chil ling requirement for elongation of leaves and inflorescences is differ ent and more quantitative than absolute. Cold (5 degrees C) stored bul bs produced leaves and inflorescences, but only leaves elongated after planting at 5 degrees C or 17 degrees C. Bulbs stored at 11 degrees C elongated both leaves and inflorescences, when planted at 5 degrees C , but only leaves, when planted at 17 degrees C. Bulbs stored at 17 de grees C developed leaves and inflorescences at both planting temperatu res, but at 17 degrees C to a lesser extent. Commercially stored bulbs - probably at 20-23 degrees C - developed leaves and inflorescences a t 5 degrees, 11 degrees or 17 degrees C planting temperature. Earliest flowering - about 17 weeks after planting end of September - were fou nd with commercially stored bulbs planted at 11 degrees C (12 weeks be fore transfer to greenhouse conditions) or with 11 degrees C-drystored bulbs (12 weeks) planted at 5 degrees C for 9-12 weeks before greenho use transfer.