Iron and zinc interaction on leaf nutrients and the essential oil of Pimpinella anisum L.

Foliar spraying of a small amount of micronutrients (iron and zinc) may increase the yield of anise(Pimpinella anisum L.), an anethole-rich important medicinal plant. In order to evaluate the effect of iron (Fe) and zinc (Zn) spraying (0, 2, 4, and 6 g l-1) on the nutrient contents and the essential oils of anise, a factorial experiment was conducted based on a randomized complete block design in Urmia University, Iran. Means comparison showed that the highest yield of biomass (2652 kg ha-1) and essential oils (49.83 kg ha-1) were observed in foliar application of 6 g l-1 of iron and 4 g l-1 of zinc. The highest leaf iron (4.89 mg g-1 dry matter) was observed at 6 g l-1 of Fe and Zn. On the other hand, there was a sharp rise of leaf zinc with higher amounts of Fe and Zn foliar sprays. The highest leaf nitrogen (35.7 mg g-1 dry matter) was obtained from 2 Fe + 6 Zn (g l-1). The highest leaf phosphorus (10.15 mg g-1 dry matter) and potassium (7.9 mg g-1 dry matter) concentrations were obtained from 4 g l-1 of Zn. In conclusion, Fe and Zn foliar applications enhanced the yield of anise through nutrient accumulation due to application of 4 g l-1 and higher. So, the highest yield was obtained from 4 g l-1 Zn with 6 g l-1 Fe for biological yield, and from 2 to 4 g l-1 Zn with 6 g l-1 Fe for essential oils.