1 Journal of Medicinal and Aromatic Plant Sciences 30 (2008) 1-4 ABSTRACT A field experiment was conducted to investigate the effects of N, P and K on yield and essential oil content and compositions of essential oil in cultivated and wild populations of German chamomile. The fertilizers N: P 2 O 5 : K 2 O were applied at the rate of 1:1:1 and with 6 levels viz 0, 30, 60, 90, 120 and 150 kg ha - 1 . The statistical design followed was a split plot design having type of chamomile population in the main plot and NPK levels in the sub-plot, having four replications. The results of this investigation indicated that various treatments of fertilizers affected oil yields. Essential oil components were also affected by nutritional treatments. (E)-b-farnesene increased with increasing the levels of fertilizer up to 90 kg ha -1 (43.36%) for cultivated and 60 kg ha -1 (40.09%) for wild populations. However, in wild population pinocarvone greatly decreased with increasing the levels of fertilizers. The amount of a-bisabolol oxide B was relatively stable, while a-bisabolol oxide A in cultivated population increased with 90 kg NPK ha -1 (8.31%) as well as when 60 kg NPK ha -1 (8.96%) was used for wild population. In cultivated population, a-bisabolol was reduced with increasing the levels of fertilizers, while this trend was opposite in wild population. Key words: Chamomilla recutita (L.) Rauschert, essential oil composition, fertilizer NPK, (E)-b-farnesene , a-bisabolol, chamazulene. INTRODUCTION In Iran, German chamomile, Chamomilla recutita (L). Rauschert, Family Asteracea, is one of the most common medicinal plants. Both cultivated and wild chamomile types are used in Iran for therapeutic purposes. Essential oils are of great importance with respect to therapeutic and commercial value [13]. The essential oil content of chamomile depends on management of nutrients both macro and micro [5, 8, 10, 11, 12]. Nikolova et al. [12] observed that the highest yields of * Correspondence to: Morteza Khosh-Khui, Department of Horticultural Science, College of Agriculture, Shiraz University, Shiraz, Iran. Tell.: 09807116243978 Mobile phone: 0989171110408 Fax: 09807112286133; E-mail: mkhoshkhui@yahoo.com ** Research Institutes of Forests and Rangelands, Tehran, Iran Effects of nitrogen, phosphorus and potassium on yield, essential oil content and composition of cultivated and wild population of Chamomilla recutita L. Rauschert AKBAR KARAMI, MORTEZA KHUSH-KHUI * AND FATEMEH SEFIDKON ** Department of Horticultural Science, College of Agriculture, Shiraz University, Shiraz, Iran Received 28 th April, 2007 essential oil in chamomile were achieved when the ratio among the major nutrient N: P: K was 1:1:1 (120 kg ha -1 ). Essential oil content of German chamomile was also reported to be significantly influenced by nitrogen levels [5, 10, 11]. In earlier investigation Gindich and Sheberstov [7] found that NPK applications raised chamomile yields and essential oil yield, whereas Franz et al. [6] found that NPK at various rates had only a marginal effect on the oil content of the flowers. Differences in the nutrient regimes induced some alternation in the chamomile essential oil quality. The á-bisabolol content was increased by elevated phosphorus levels, while chamazulene content was a relatively stable characteristic and was not affected significantly by variation of the doses of tested nutrients [8]. Correa- Junior et al. [13] reported that the á-bisabolol percentage was not significantly influenced by the nutrients. Nitrogen application increased á-bisabolol and chamazulene contents but decreased á-bisabolol oxide A and B contents in the essential oil [5]. Increasing N and P levels increased the oil content, and increasing K reduced it. High N levels and low K levels caused an increase in the bisabolol content of the essential oil, while low N and high K increased the bisabolol oxide content [6]. Earlier work on the subject is scanty as well as contradictory. Looking in to the above the present investigation was to elucidate the effects of nitrogen, phosphorus and potassium on essential oil yield and quality of essential oil of two cultivated and wild populations of German chamomile. MATERIAL AND METHODS Treatments and experimentation The experimental site is situated at 29° 502 N latitude and 52° 462 E longitude and 1810 m above mean sea level. Field experiment was conducted following a split plot design with four replication having type of chamomile population in the main plots and fertilizer NPK in the sub-plot. Nitrogen, phosphorus and potassium were applied through ammonium sulphate, triple super-phosphate, potassium sulphate respectively at N: P 2 O 5 :K 2 O ratio of 1:1:1 and six treating levels of NPK 0, 30, 60, 90, 120 and 150 kg ha -1 . Seeds were sown in the first week of October at the research farm of Shiraz University, Iran and uniform seedlings of 35 day old were planted in plots of 6 m 2 sizes, in rows 30 cm apart having plant