Improvment of Physiological and Agronomic Characteristics of Winter Oilseed Rape (Brassica napus L.) with Nano-Selenium Application

To investigate the effect of foliar selenium nanoparticle applications on the agronomic and yield characteristics of winter oilseed rape, with three levels (0 (control), 25 and 50 mg.L-1) at two growth stages (6-8 leaves and 50% flowering) at the research farm station of the University of Mohaghegh Ardabili during 2018-2019 was studied. The results showed that the selenium nanoparticle applications increased the photosynthetic pigments and the relative water content (RWC) of the leaves significantly. Foliar spraying with 50 mg.L-1 selenium nanoparticle increased in the chlorophyll a and b and total chlorophyll content by 37.04, 44.51 and 39.68%, respectively, as compared to the control treatment. On the other hands, selenium nanoparticle application increased the plant height, number of branches and stem diameter via improving the photosynthetic pigments content and RWC of winter oilseed rape significantly. The biological yield, harvest index and seed oil content of 25 and 50 mg.L-1 of selenium nanoparticle treatments were significantly higher than those of the control. The foliar spraying of oilseed rape plants with selenium nanoparticle applications improved the grain yield throught increase in the number of pods per plant, the number of seeds per pod and the 1000 grain weight significantly. Thus, the highest improvement in the grain yield per unit area (about 34.16 %) was obtained with application of 50 mg.L-1 selenium nanoparticles in comparison with control treatment. In general, the application of 50 mg.L-1 selenium nanoparticles had a positive and significant effect on the physiological (photosynthetic pigments content and RWC) and agronomical characteristics at plants, as to the plant height, branches number, stem diameter, the number of pods per plant, the number of seeds per pod, the 1000-grain weight and seed oil content of winter rape.