Physical Seed Treatment and Their Effects on Seedling Emergence and Yield of Ribwort Plantain (Plantago lanceolata) in Delayed Sowing Date

To investigate the possibility of improving seedling emergence, stand establishment and yield of late sown ribwort plantain (Plantago lanceolata) by seed priming pot and field experiments were conducted at the Islamic Azad University, Tabriz, Iran during 2013. The ribwort plantain seeds were differently treated by ultrasonication, laser, magnetic field, gamma and beta irradiations all for 3.5 and 5 min. and were sown on 5th and 20th of May. All of the seed priming treatments reduced seedling emergence time, 50 % of seedling emergence and mean emergence time as compared with control. Highest seedling dry weight (0.49 g.plant-1) resulted from magnetic field treatment for 5 min. followed by magnetic field for 3.5 min. and ultrasonic treatments (0.40 g.plant-1). A further reduction in exposure time of magnetic field from 5 to 3.5 min. decreased seedling vigor index. When seeds were sown in 5th and 20th May, maturity period of plots treated with magnetic field and ultrasonic happened to range between 112.2 and 99.7 days after sowing, respectively. Leaf area index remained statistically unaffected due to a delay of 15 days in sowing date. Under field conditions, there was not significant difference between seed yields from sowing dates, and the yield ranged from 176 kg.ha-1 in control, gamma and beta irradiations up to 211 kg.ha-1 in magnetic field and ultrasonic treatments. It can be concluded that priming ribwort plantain seeds by magnetic field and ultrasonic waves would effectively be used to improve the crop performance and yield especially in late sown plants.