17 S. Baser Kouchebagh F. Farahvash B. Mirshekari H. Kazemi Arbat F. Rahimzadeh Khoei Journal of Animal and Plant Sciences JAPS 20142014/12/01 24 6 1863-1868 1018-7081 NA <p>Seed priming has been reported to enhance growth of plants. To evaluate the effect of some physical seed priming materials (ultrasonic, gamma, beta, laser, magnetic field, irradiations and hydro-priming) on yield and yield components of sunflower, field experiments were conducted at Islamic Azad University, Tabriz branch, Iran during 2011-2012 in a randomized complete block design, with three replications. The results revealed that crop LAI, following pre-sowing treatments, increased by magnetic fields, laser for 5 and 15 min. and ultrasonic up to 3.36, 3.41, 3.91 and 3.53, respectively. Beta and gamma rays, hydropriming and non-priming of seeds reduced it at 70 DAE. Highest mean yield produced from seeds treated with laser (419.7g.m-2) and magnetic field (379.8g.m-2) for 5 min. However, it decreased by increasing laser duration from 5 to 10 min. Biomass produced ranged from 947.4 g.m-2 in seeds primed under laser for 5 minutes. and 406.7 g.m-2 in non-priming ones. It was also found that sunflower seeds irradiated with laser for 5 and 10 minutes and magnetic fields resulted in highest harvest index (49.1%), as compared with other treatments. It may be concluded that sunflower<strong>&nbsp;</strong>growers could improve crop yield by priming the seeds with magnetic field and laser irradiation before sowing.</p> Magnetic field, Oil percentage, Physical priming Pakistan Agricultural Scientists Forum https://thejaps.org.pk/AbstractView.aspx?mid=2014-JAPS-266