Effect of different concentrations of iron and boron on growth and physiological properties of Achillea millefolium L.

Plants need essential nutrients for their growth and development. Iron and boron are micronutrients that are needed by plants in very small concentrations. This study was conducted as a pot experiment to investigate the effect of iron and boron on Achillea millefolium in a factorial randomized complete design with three replications. Iron at three levels (0, 5 and 20 μM) and boron at three levels (25, 50 and 75 μM) were selected. The results showed that the effects of iron, boron and their interaction on most of the growth and physiological indices of Achillea millefolium was significant. Iron (20 μM) and boron (75 μM) and their interaction significantly increased chlorophyll a, b, total chlorophyll content, chlorophyll a / b ratio, carotenoid compared to the control samples (20 μM iron and 25 μM boron). Different concentrations of boron had no effect on relative water content. Also, different concentrations of boron and iron did not lead to a significant change in the root dry weight. Iron significantly influence on root and shoot iron concentration and soluble leaf protein. Boron had no significant effect on shoot iron concentration, but changed other two indices significantly. The maximum amount of root and shoot iron was 951 and 620 µg/g DW, respectively. In conclusion, it seemed that treatments of Achillea millefolium with iron (20 µM) and boron (75 µM) leads to significant increase in growth and physiological parameters of this plant.