Investigating some quantitative and qualitative characteristics of wild marjoram (Origanum vulgare sub sp. Virid.) as affected by different levels of azocompost and urea

In order to investigate the effect of organic and chemical fertilizers on growth characteristics of wild marjoram, a factorial experiment was conducted based on randomized complete block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad during 2012-2013 growing season. Treatments were comprised of four urea levels (0, 21.7, 108.7 and 195.7 kg.ha 1) and four azocompost levels (0, 2.2, 11.1 and 20 t.ha-1). The ratings from each fertilizer were adjusted separately based on 0, 40, 80 and 120 kg N.ha-1. In the present study, several traits such as plant height, canopy crown, number of lateral branches/plant, number of flowers/plant, dry weight of leaves and flowers, total dry weight, leaf area index, economic yield, harvest index, essential oil content and yield were measured. The results showed that main effects of chemical and azocompost fertilizers on all characteristics of wild marjoram except for harvest index and essential oil content were significant. In addition, interaction between experimental factors was significant for all traits except for essential oil content. Plants treated with 40 kg chemical fertilizer.ha-1 and 80 kg Azocompost.ha-1 had the highest values in all traits except for canopy crown, total dry weight, essential oil content and yield. At the highest when compared with the lowest N level, a significant increase of 577.68 and 441.7 kg.ha-1 in economic yield occurred by applying azocompost and urea, respectively. It seems that the application of azocompost had better results than nitrogen fertilizer alone. The highest correlations (r=0.99**) occurred for number of branches.plant-1 vs. plant height, for number of branches.plant-1 vs. plant height and for dry weight of leaves and flowers vs. economic yield. The number of lateral branches.plant 1 (r=0.98**), leaf area (r=0.97**) and plant height (r=0.96**) had the highest positive correlation with economic yield, indicating the importance of these traits in contributing to final yield.