For investigating the effects of osmopriming and hydropriming treatments on the germination indexes and seed vigor on Sheep Fescue (Festuca ovina), two experiments was done. In the first experiment which was fulfilled based on randomized complete block design with four replicates, effect of polyethyleneglycol 6000 solution was investigated in five osmotic potentials (-8, -10, -12, -14 and -16 bar), two temperatures (15 and 25o C) and four times (12, 24, 36 and 48 hours). Second experiment was fulfilled by using distilled water in two temperatures (15 and 25oC) and four times (12, 24, 36 and 48 hours) with four replicates on the above mentioned. Then, based on the maximum germination rate and vigor indexes, the best treatment composition was determined for osmopriming and hydropriming solutions from the view point of osmotic potential, temperature and priming duration. In osmopriming experiment, treatment composition of 12 hours in 15oC and -8 potential had the most significant effect on the percent and speed of germination, length of radicle, coleoptile and seedling as well ass vigor indexes in Tall Fescue. In hydropriming effect on this plant, the same condition as osmopriming was observed and in the majority of evaluated traits, treatment composition of 12 hours prime and 15oC had the maximum numerical value in comparison to control and other treatments. Finally, it is inferred that favorite effects of osmo and hydropriming in 15oC temperature are increased in comparison with the control group (none prime seeds).b
