مشخصات پژوهش

In order to study the effects of applying chemical and biofertilizers on some quantitative and qualitative characteristics of lemon verbena (Lippia citriodora L.), a factorial CRD experiment including 18 treatments with 3 replications, was conducted at Bu-Ali Sina University research greenhouse. The treatments were: vermicompost (0, 20 and 40 V/V), phosphate biofertilizer (application and no-application) and chemical fertilizer (0, 50 and 100% of the recommended amount equal to 0, 0.52 and 1.04 gr/pot respectively).The essential oil was extracted by hydro distilation method by using a clevenger apparatus and were analyzed by GC and GC/MS. Results were showed that the maximum plant height, number of branches per plant, fresh and dry weight and the highest percentage of essential oil were obtained as a result of using 40% vermicompost. Plants treated by 50% of recommended NPK + 40% vermicompost showed the highest rate of photosynthesis and transpiration. The maximum nitrogen concentration in leaf tissue was obtained from applying 100% of the recommended amount of NPK + biophosphate. Applying 100% recommended NPK + 40% vermicompost, resulted in higher phosphorus concentration in leaves. The highest concentration of potassium in leaves was obtained from plants treated with 40% vermicompost. 35 different compounds were identified in the essential oil among them geraniol, davanone and p-cymene were the main components. The highest amounts of these three compounds were obtained under 40% vermicompost treatment. Generally, in order to achieve sustainable agriculture, it seems that reduction of chemical fertilizers and replacing them with vermicompost can be an effective method.