PHYSIOLOGICAL AND BIOCHEMICAL RESPONSES OF ACHILLEA MILLEFOLIUM GROUP-RELATED CULTIVAR PROA TO DIFFERENT NITROGEN REGIMES

In the present study the effect of different nitrogen amounts (0 g [N-0], 0.45 g [N-1], 0.9 g [N-2] and 1.35 g N [N-3] per pot, corresponding to 0 kg.ha(-1), 50 kg.ha(-1), 100 kg.ha(-1) and 150 kg.ha(-1) N application in field conditions) and application times (at sowing, vegetative stage and pre-bloom stage) on the yield, relative water content, total nitrogen content and nitrogen use efficiency in plants of the Achillea millefolium group-related cv. Proa was investigated Antioxidant activity, flavonoid content, rate and composition of the essential oils were also determined Application of N-2 increased the dry herbage and flos production, total nitrogen amount and nitrogen use efficiency, without affecting the essential oil rate while reducing the antioxidant activity. Higher amounts (N-3) of nitrogen maintained the dry herbage and flos yield at levels similar to N-2 but decreased the antioxidant activity and rate of the essential oil. The major component of the essential oil, chamazulene, was negatively (N-1, N-2) or not influenced (N-3) by the nitrogen application, while variable changes were registered in the content of the other components. The data point to the nitrogen regime being a subtle tool for regulating the performance of cv. Proa plants. Biotechnol. & Biotechnol. Eq. 2013, 27(2), 3649-3653