Gibberellin Inhibitor Treatments before Planting Control Plant Height of Narcissus tazetta by Affecting Growth Parameters

Abstract

The effects of flurprimidol and paclobutrazol, treatments as preplant bulb soaks on plant height, growth parameters and other properties of Narcissus tazetta L. grown in pots were investigated. Bulbs were soaked in flurprimidol at 0, 10, 20 mg L-1 or paclobutrazol at 0. 100, 200 mg L-1 before planting. The effects of gibberellin inhibitors on the flower number, flowering time, flower life, plant height, leaf length and quantitative measurements (specific leaf area, leaf area ratio, leaf thickness. leaf weight ratio and stem weight ratio) were determined. When narcissus reached to the sale stage. plants were taken to the laboratory where the temperature stable at 20 degrees C to evaluate the postproduction quality. The shortest plant height (6.25 cm, 63% shorter than control) was obtained from the 20 mg L-1 flurprimidol application. Plants applied with 200 mg L-1 paclobutrazol were 59% shorter than control with 7.00 cm plant height. Gibberellin inhibitors also shortened the leaf length and increased the leaf thickness, whereas decreased leaf area ratio and specific leaf area by shortening the plant height. The effects of gibberellin inhibitors on plant height continued after harvest (product ion) in marketing and consumer (laboratory) conditions. The plant heights of treated plants were 10.87 (20 mg L-1 flurpirm idol) and 10.37 (200 mg L-1 paclobutrazol) cm, while with the control plants were 26.75 cm in with laboratory conditions.