Effect of Fe and Zn foliar application on plant characteristics and essential oil content of anise (Pimpinella anisum L.)

To evaluate effects of foliar application of Fe and Zn on morphology and yield of anise, afactorial experiment was conducted using randomized complete block design with three replications at the Agricultural Research Station, Urmia University, Urmia, Iran, in 2008. Treatments were Fe and Zn application (0, 2, 4 and 6 g.l-1). Results showed significant effect of Fe and Zn on the number of branches and the stem diameter, and the interaction of Fe and Zn on chlorophyll content, the number of seed.plant-1, biomass yield, seed yield was also significant. The highest SPAD value (chlorophyll content) (37.9) was observed at 6 g.l-1 of Fe and Zn, and the lowest value (15.3) was measured at 0 gl-1 Fe and 2 g.l-1 Zn. The highest biomass yield (2652 kg.ha-1) and seed yield (1372 kg.ha-1) was obtained from 6 g.l-1Fe and 4 g.l-1 of Zn and the lowest biomass yield (716 kg.ha-1) and seed yield (470 kg.ha-1) belonged to 0 gl-1 and 6 g.l-1 of Fe and Zn, respectively. Results also showed that the highest essential oil yield (50 kg.ha-1) was obtained from 6 g.l-1 Fe and 4 g.l-1 of Zn, and the lowest essential oil yield (18 kg.ha-1) belonged to 2 g.l-1 Fe and Zn. Homolen and Estragole was largest component both with 18% essential oil measured by gas chromatography analysis. It is concluded that foliar application of Fe increased seed yield, chlorophyll content and essential oil yield of anise and this was enhanced by foliar application of Zn.