The effect of GA3 application on yield and quality properties in oil bearing rosa (Rosa damascena Mill.)

The aim of the study was to investigate the effect of GA3 applications on yield and quality characteristics. The study was carried out as the split plot designs in the randomized blocks, GA3 was applied at a dose of 0, 25, 50, 75 and 100 ppm when the plants began to bud in the plots and the pink petals began to appear on sepal leaves and one week after this date. Flowers were picked at the beginning of flowering (1-7 days), middle (8-14 days) and at the end of the (15-21 days) flowering season. GA3 applications increased flower diameter, petal ratio, 100 flower weight, flower and essential oil yield up to 50 ppm. But number of components in the essential oil increased up to 25 ppm doses, and started to decrease at the copsequent GA3 doses. The geraniol content decreased from 36.69% to 21.16% from the control to 100 ppm at the beginning of flowering, from 27.34% to 12.93% in the mid-flowering, and from 22.33% to 21.14% at the end of flowering. The content of nonadecene and nonadecane at the beginning of flowering increased from 1.44% to 2.47% and 16.50% to 23.58%, respectively, from control to 100 ppm dose, from 1.69% to 2.66 and from 17.15% to 21.23% in mid-flowering. At the end of flowering, nonadecene content decreased from 2.56% to 1.87%, while nonadecene content increased from 20.66% to 29.45%. Finally; it is recommended to apply 25 ppm GA3 to obtain high flower and essential oil yield and its components.