GROWTH RETARDATION OF NARCISUS TAZETTA DURING FORCIN

Abstract

Bulbs of the Chinese Sacred Lily (Narcissus tazetta) are forced in water about 28 days before Chinese New Year. Excessive leaf and scape length may necessitate tying to render the plants presentable. No. 1 bulbs which had been cleaned and placed in water for 2 days were treated with 10 ppm ancymidol, 50 ppm paclobutrazol, 25 ppm uniconzole, 10 ppm flurprimidol, or 100 ppm ethephon. At 70% of control plant height, ethephon-treated plants were shortest, and flowering was not delayed. Daughter bulbs were soaked in 50 ppm flurprimidol to determine the most effective stage at which to treat. Soaking the dry bulbs for 1 hour at 36°C was most effective (58% of control), but delayed flowering more than a week. Soaking the bulbs for one hour when emerging roots were @ 0.5 cm long was also effective (65% of control). At 11 days of forcing when emerging leaves were 4 - 6 cm long, the entangled root sytems wer soaked in the retardant which was then drained off. This treatment achieved 74% of control growth. Scap lengths in all flurprimidol treatments were 60-65% of the foliage length compared to 82% for the controls.