Yield and Oil Constituents of Chamomile (Matricaria chamomilla L.) Flowers Depending on Nitrogen Application, Plant Density and Climate Conditions

Abstract

Although chamomile is found as a wild species throughout Iran, there is yet little information about cultivation of commercial cultivars of chamomile under various cultural practices in climatic conditions of Iran. In order to investigate the effects of different levels of nitrogen fertilization and plant densities on the yield and essential oil constituents of chamomile C.V. Bodegold flowers, this experiment was set up at the Ferdowsi University research field, Mashhad, Iran during 2006-2007. The experimental design was on the base of two-factor randomized complete blocks design (RCBD) with three replications. The first factor was plant density at four levels including D1 = 20, D2 = 25, D3 = 40 and D4 = 50 pl.m−2 and the second factor was nitrogen in the form of urea (% 46 nitrogen) at three levels, including N0 = control (absence of fertilization), N1 = 10 and N2 = 20 g.m−2. Observations were recorded on plant height, flower and disc florets diameter, dry flower yield, content (%) and yield of essential oil and main compounds of the oil. The crop responded significantly to different plant density. Plant height increased with increasing plant density from 20 pl.m−2 up to 50 pl.m−2, whereas the diameter of disc florets followed the reverse trend. Yield of dry flower and essential oil increased with plant density. Application of urea affected all observation of this study significantly. The maximum yields of dry flower and essential oil were observed at 50 pl.m−2 with 20 g.m−2 urea fertilization. The main oil compounds oil was including: α-bisabolol oxide A (53.45 ± 5.94 %), α-bisabolol oxide B (9.90 ± 3.03 %), α-bisabolone oxide A (5.24 ± 1.60 %), chamazulene (4.29 ± 2.78 %), (Z)-β-farnesene (2.75 ± 1.06 %) and spathulenol (0.81 ± 0.44 %).