The effect of ancymidol on forcing tulips

This study was designed to compare the effects of ancymidol applied as a soil drench and as a bulb-dip to Tulipa gesneriana L. 'Paul Richter', a forcing tulip. Three treatments consisted of: 1. bulb-dip applications of ancymidol (0, 2, 4, 8, and 10 mg/liter), prior to cool treatment, 2. soil drench applications at the beginning of the forcing period, and 3. bulb-dip applications after six weeks of cooling. The soil drench applications were significantly more effective than the other two treatments in retarding scape growth, measured as length and as dry weight. Two mg/liter ancymidol soil drenches were as effective in retarding scape growth as 10 mg/liter soil drenches. Ancymidol applications caused no change in leaf length or width, flower size or color, the date at which the tulips reached the salable stage, or the shelf-life of the flowers.