An assessment was made of the usefulness for forcing of five cultivars of Hyacinthus orientalis L.: ‘Carnegie’, ‘City of Haarlem’, ‘Delft Blue’, ‘Jan Bos’, and ‘Lady Derby’. The bulbs were planted on 14 October 2003 and 2004 in Flexy-tray type of pallets filled with water and in plastic boxes with a standard medium. The bulbs were cooled for 12 or 14 weeks. It was found that forcing lasted shorter in the water-filled trays, while longer inflorescence stems were obtained in plants forced in the standard medium. The cooling of the bulbs for 14 weeks resulted in the shortening of the forcing time and in the lengthening of inflorescence stems.

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