Effect of nano and balk titanium dioxide on flowering and morphophysiological traits of Rosa damascena under different irrigation regimes

Various environmental stresses are one of the most important causes of many problems in agricultural production and drought stress is one of these tensions. Considering the role of nanoparticles in improving the yield and resistance of plants to environmental stresses, this experiment was conducted on Rosa damascena as a factorial experiment based on a completely randomized design with three replications was performed in the greenhouses of the Faculty of Agriculture of Ferdowsi University of Mashhad in spring and summer of 1397. The treatments consisted of two irrigation regimes (every three days (control), and every six days) and five levels of titanium (0 (control, no titanium), 15 ppm titanium dioxide, 30 ppm titanium dioxide, 15 ppm nano-titanium dioxide, 30 ppm nano-titanium dioxide). The results showed that although the interaction of two treatments of irrigation and titanium dioxide regimes on any of the morphological traits was not significant, the simple effect of irrigation regimes on root dry weight, flowers dry weight, number of flowers and Stem diameter had a significant effect. Thus, the level of 15 ppm nano-titanium dioxide with 0.23% had the highest essential oil yield. The electrolyte leakage was observed at 49% for 3 days of irrigation and 58.9% for 6 days irrigation intervals. The highest amount of electrolyte leakage was in control (68%) and then in 30 ppm titanium dioxide treatment (62.9%.). Increasing the distance between irrigation resulted in increased total phenol and reduced stomatal conductance. among the titanium levels, the highest total phenol (1.13 mg / g) was observed in 15 ppm nano-titanium dioxide treatment and the highest stomatal conductance was observed in 15 and 30 ppm nano titanium dioxide treatments. In general, the use of titanium at all levels used, especially in the 15-ppm nano titanium dioxide, was effective in improving the vegetative and physiochemical properties of Rosa damascena