Evaluation of Agro-Morphological Characters And Oil Percentage of Origanum syriacum L. and Origanum majorana L. at Three Dates Of Initial Cutting

This study was conducted during the 2006/2007 and 2007/2008 seasons, under open field and plastic houses conditions in the Jordan Valley, to evaluate yield and quality of Origanum syriacum, and Origanum majorana cultivated accessions and wild population at three dates of initial cutting. Several agro-morphological traits including oil content were studied. Spilt-plot arranged in a randomized complete block design with repeated measurement design replicated three times was used. The highest fresh and dry weight production was found to be produced when the first cut was performed at February 26. The highest essential oil percentage was obtained when the first cut was performed in March 26 for all population/accessions. The cultivation of Origanum under plastic house in Jordan valley positively affected plant height, fresh and dry weight, leaf/stem ratio, leaf area but it had no significant effect on essential oil content. Essential oil content varied during the growing seasons. In the second season the highest essential oil content was for the wild O. syriacum population when the first cut was performed on March 26 (2.12%), followed by the cultivated O. syriacum accessions 1 (1.91%) and 2 (1.90%) and then the two accessions of O. majorana with 1.66% each.