The effects of nitrogen and foliar application of iron amino chelate on yield and growth indices of dill (Anethum graveolans L.) medical plant

In order to assess the effects of different levels of nitrogen (N) and foliar application of iron amino chelate on yield and growth traits of dill medical plant, a factorial experiment was conducted in 2011 using a completely randomized design and three replications. In this experiment, five levels of N (0, 50, 100, 200 and 400 kg/ha N from urea source) and two levels of foliar spray of iron amino chelate (with and without foliar spray) with concentration of 2 g/liter were used. At the end of growth period, fresh and dry weight of aerial parts, leaf, stem and roots, ratio of fresh and dry leaf weight to stem weight, height, stem diameter, 1000-seed weight and iron concentration and uptake in the aerial parts were measured. The results of ANOVA showed that the effects of N were significant on all measured traits, except fresh and dry weights of roots. Foliar spray of iron amino chelate increased significantly all measured traits, except fresh and dry weights of roots and plant height. The interactive effects of N and foliar spray were significant on all measured traits except the fresh and dry weight of stem, dry matter, ratio of fresh weight of leaf to stem, fresh and dry weights of roots, and iron concentration and uptake in the aerial parts. The highest fresh and dry weights of aerial parts (714.2 and 102.7 g/m2, respectively) were obtained from the application of 400 kg N/ha plus foliar spray of iron amino chelate. The lowest fresh and dry weights of aerial parts (199.7 and 45.6 g/m2, respectively) were obtained in the control treatment.