Abstract

Abstract Commercial producers of ornamental bulb plants use a variety of growth regulators to influence plant growth, flowering and cut flower quality. It was also mentioned that nitrogen had positive effect on flower quality in bulb plants. Narcissus is a valuable and economic winter flowering bulb used as a landscape plant or cut flower. This experiment was carried out to determine the combined effect of benzyladenine (BA) with Potassium nitrate (KNO3) fertilization on flowering and some quality characteristics of Narcissus tazetta cut flower under ̒ Behbahan ̓ climatic condition )Khuzestan province, Iran) in autumn planting. The bulbs were soaked in different concentration of BA (0, 100, 200 and 500 mg/L) for 24 hours before planting them into the pot or BA was applied prior to flowering as a foliar spray treatment. At the three leaf stage or prior to flowering, KNO3 (0. 1, 2, 4 g/kg Soil) were applied. The results indicated that interaction of BA and KNO3 had significant effects on the time from planting to harvest, duration swell spot, burst duration spot, flower diameter and dry weight cut flower. Further investigations are required to confirm the hypothesis presented here about interaction of plant growth regulators and nitrogen fertilization on growth and flowering of Narcissus tazetta. Key words: Plant growth regulators, Nitrogen, Narcissus (Narcissus tazetta), Cut flower, Quality