Investigation of water deficit and physical seed priming effects on some morphophysiological traits and grain yield of maize (Zea mays L.)

To investigate the physical seed priming of maize under water deficit, a split plot experiment based on completely randomized block design with three replications was conducted at the Agricultural Research Station of Islamic Azad University, Tabriz Branch in 2014. Main plots consisted of two irrigation levels (control and water deficit respectively 70 and 110 mm evaporations from class A pan) and sub plots of eleven levels of physical priming (gamma and beta rays with fixed velocity of two micro curie, laser with continuous wave He-Ne with wavelength 6328 angstrom, magnetic field with 40 Mt and ultrasonic waves with maximum 3 wat/cm2 in 5 and 10 minutes along with control, without any treatment). Based on the results obtained, grain yield and leaf area index decreased by 18.5 and 23% respectively under drought stress condition in comparison with normal irrigation (70 mm evaporation from the pan). Proline concentration of leaves increased under drought stress by 38% as compared with control treatment. The highest leaf area indices by using magnetic field and 5 minutes laser and gamma irradiations obtained to be 3.95. The highest grain yield belonged to treatment of 5 and 10 minutes of magnetic field and to treatments of 5 minutes gamma and laser irradiations. Increasing treatment time from 5 to10 minutes, of gamma and laser irradiations decreased grain yield by 20 and 17%, respectively. It can be concluded that physical seed priming by magnetic field, gamma and laser irradiations for short times can be recommended for higher grain yields.