Effect of nitrogen and phosphorus fertilzation and planting dates on growth, flower yield and methoxalen conceration in Calendula officinalis L.

Abstract

Study was conducted in Botanical Garden, Biology Department, College of Science, University of Baghdad, sowing dates were (1/10 / 2000) and ( 1/11/2000), three levels of nitrogen fertilizer (0, 25, 50) Kg N/ ha. as urea (46% N) and three levels of Phosphorus fertilizer (0, 25, 50) kg p2O5/ ha. as triple super phosphate (48 - 52 )% P2O5 and their interactions upon growth, flower yield and methoxalen concentration of (Calendula officnialis L. Var lemon queen). All treatments were arranged in Randomized Complete Block Design with three repilications. Methoxalen was sperated and massuaard with HPLC. The results can be summarized: the first sowing date was significantly superior than the second sowing date in number of branches / leaf area dcm2, number of inflorescence/ plant, flower yield, fresh and dry weight and concentration of methoxalen. Nitrogen and phosphorus treatment were significantly increased in these parameters.