Effect of irrigation regimes and nitrogen on phenology, grain yield and essential oil of chamomile (Matricaria chamomilla L.)

In order to determe suitable irrigation regime and nitrogen rate in German chamomile (Matricaria chamomilla L.) with attention to some yield related traits, an experiment was conducted in Tabriz region in 2007 with three factors including irrigation regimes (I1=6; I2=12, I3=18 days once) as main plots, and factorial combination of urea rate (N1=50; N2=100, N3=150 kg ha-1) and nitrogen splitting (T1= 100% at sowing time; T2= 50%:50% at sowing and stem elongation stages, T3= 25%:50%:25% at sowing, stem elongation and early flowering stages, respectively) as subplots, in a randomized complete blocks design with a split factorial arrangement. Results indicated that with increasing irrigation intervals from 6 to 18 days, time to flowering at N1, N2 and N3 accelerated 8.2, 12 and 13.5 days, respectively. Seeds for I1N3 and I3N1 treatments, ripened later and earlier than other treatments, respectively. Flower yield increased 7.5%, with increasing nitrogen level from N1 to N2. Seed essence percentage ranged from 0.48% at I3N3 to 0.98% at I2N2. Nitrogen splitting influencedessence yield, and the highest essence yield (2.82l ha-1) was obtained for T2 treatment. With increasing of irrigation intervals from 12 to 18 days, essence yield and seed yield at I3 decreased comparedto I2, about 49% and 37%, respectively. Urea application at T3 compared with T2 and T1, increased seed yield 9.7kg ha-1 and 17.8kg ha-1, respectively.