Improvement of Seed Germination, Seedling Vigor and Yield of Achillea santolina and A. millefolium by Physical Priming Techniques

To study the effect of physical primings on growth and yield of Achillea santolina and A. millefolium two experiments were conducted in Islamic Azad University of Tabriz, Iran, with three replications during 2014. Treatments were ultrasonication, laser, magnetic field, gamma and beta radiations for 5, 10 and 15 min. along with a control. By increasing ultrasonic exposure time of Achillea santolina seed its germination was delayed. Seeds treated with ultrasonic wave for 5-10 min. and laser for 5 min. produced seedlings with higher vigors. Seeds of A. millefolium hydroprimed germinated only by 65%. Also, seeds of plants treated by magnetic field, gamma and beta radiations produced weaker seedlings. Achillea santolina plants treated by ultrasonic waves produced higher essence percentage. Essence yields of seeds of both species expesed to ultrasonic wave and laser were higher than the other ones. The effects of seedling vigor index and number of secondary branches on yield of both species were 1.90 and 1.85 times greater than that of final germination percentage. Ultrasonication and laser treatment of Achillea seeds resulted in both strong seedlings and higher essence yields.