Effects of Some Plant Growth Regulators on Quality of Potted Sunflower

Abstract

This study was carried out to evaluate the effects of different plant growth regulators on the ornamental sunflower plant. The seedlings belonging to Helianthus annuus L. cv. Sunsantion F1 were planted in plastic pots (2 L) containing peat: perlite (1:1, v/v) medium at four true leaf stage. Spray treatments of aminoethoxyvinil glycine (AVG; 250 and 500 ppm), Promalin (5 and 10 ppm), Thidiazuron (TDZ; 5-10 µM), Ethephon (100 ppm) were applied to seedlings 20 days after transfer to the pots, and treatments were repeated 10 days after the first application. Flower life (days), flower diameter (cm), stem diameter (cm) and plant height (cm) were determined. According to statistical analysis, AVG at 250 ppm significantly increased the flower life from 9.17 d in control plants to 11.08 d whereas there were no significant effects on flower diameter and plant height. Both concentrations of Promalin and TDZ increased stem diameter significantly. However, TDZ increased the flower life from 9.17 d (control plants) to 10.36 at 10 µM and 10.33 at 5 µM TDZ. Ethephon application prevented flower bud opening and caused the leaves to be yellowing. These results may suggest AVG and TDZ pre-treatments increase the quality and shelf-life of the potted sunflower plant.