Evaluation of Lallemantia iberica (MB) Fischer & Meyer essential oil quantity and quality by application of conventional chemical and nano fertilizers

In order to investigate the effects of combined and separate application of macro and micro nano fertilizers with chemical fertilizers on quantitative and qualitative traits of medicinal plant dragon’s head (Lallemantia iberica (MB) Fischer & Meyer), a field experiment was performed based on the randomized complete block design (RCBD) with seven treatments and three replications on the research farm of Maragheh University in 2017. Experimental treatments included the use of 100% conventional chemical fertilizer (urea and triple superphosphate with values of 150 and 100 kg ha-1, respectively), 100% macro nano fertilizer, 100% micro nano fertilizer, 50% macro nanofertilizer+50% micro nano fertilizer, 50% chemical fertilizer+50% macro nano fertilizer, 50% chemical fertilizer+50% micro nano fertilizer, and 50% chemical fertilizer+25% macro nanofertilizer+25% micro nano fertilizer. The results showed that the highest (73.3) and lowest (59.1) chlorophyll indices were obtained by applying 50% chemical fertilizer+25% macro nano fertilizer+25% micro nano fertilizer, and separate application of 100% micro nano fertilizer, respectively. Also, the highest values of number of lateral branches, main stem length, number of flower cycles per plant, number of seeds per plant, biological yield, seed yield, 1000-seed weight and seed mucilage content were obtained in 50% chemical fertilizer+25% macro nanofertilizer+25% micro nanofertilizer treatment. Chemical analysis of the essential oils demonstrated that linalool, menthol, geraniol, geranial, menthyl acetate, β-bourbonene, geranyl acetate, (E)-caryophyllene, germacrene D, spathulenol and caryophyllene oxide were the main constituents of essential oils. The highest content of β-bourbonene, caryophyllene oxide, (E)-caryophyllene, menthol, and geraniol was obtained with the combined use of 50% chemical fertilizer+25% macro nanofertilizer+25% micro nano fertilizer. In general, based on the results of the present research, the combined use of chemical fertilizers and macro and micro nano fertilizers can be recommended due to the increased seed yield and dragon’s head qualitative traits under rainfed conditions.