Effects of seed priming with microelements of Fe and B on some germination parameters and yield of marigold (Calendula officinalis L.)

In order to evaluate the effect of seed priming with iron and boron on germination parameters and yield of marigold (Calendula officinalis L.), laboratory and field experiments were conducted in Islamic Azad University, Tabriz Branch, with three replications in 2011. The studied treatments were the seed priming with iron and boron at concentrations of 0.5%, 1%, 1.5% and 2%, distilled water as control and two combined treatments of Fe1.5%+B1% and Fe2%+B1%. Results revealed that seed priming with Fe 1% and 1.5% and B, alone or in the combined treatments, improved the seed germination speed of marigold as comared to the control. The seedling vigor index of primed seeds in Fe 1.5% solution increased up to 2.3. In the seeds primed with boric acid, the seedling vigor index was limited when the concentration of B in solution increased more than 1%. Dry flower yield in treatments of Fe1.5%+B1%, Fe1.5%, Fe2% and Fe2%+B1% were 39%, 34%, 24% and 28% more than control, respectively. Essential oil values among treatments ranged from 0.1 mL m-2 in B1.5% and B1% to 0.27 mL m-2 in Fe1.5%+B1%. Lower essential oil yield was obtained for the treatment of Fe2%+B1% (0.14 mL m-2) compared to B1.5% and B1%. Our results clearly showed that seed priming with iron and boron could be recommended as a method for improvement of essential oil yield in marigold.