Changes in Essential Oil Composition and Leaf traits of Basil (Ocimum basilicum L.) Affected by Bio-stimulators / fertilizers Application

Background: Basil (Ocimum basilicum L.), a member of the Lamiaceae family, has traditionally been used as a medicinal plant in the treatment of headaches, coughs, diarrhea, constipation, warts, worms, and kidney malfunctions. Objective: To investigate the foliar application effects of bio-stimulators and bio-fertilizers on morphological and phytochemical traits of basil (Ocimum basilicum L.). Methods: Bio-stimulators in three commercial formulations of aminolforte, kadostim and fosnutren (with concentration of 1.5 L.ha-1) through foliar application, and bio-fertilizers in three commercial formulations of nitroxin, super-nitro plus and barvar II (with concentration of 0.5 L.ha-1) through seed inoculation were considered as two studied factors. Results: The results showed that the interaction effect of bio-stimulators and bio - fertilizers was significant (p<0.01) on all of studied parameters except of chlorophyll content (SPAD value). The highest leaf fresh weight (25.47 g/plant) and leaf dry weight (6.48 g/plant) were obtained under fosnutren and nitroxin treatment, also maximum leaf number (206.33) was recorded in aminolforte and nitroxin treatment. The highest leaf area (1302.2 mm2/plant) was observed in kadostim and nitroxin treatment. Also results showed that the highest content of essential oil (0.43%) was obtained in aminolforte and nitroxin, methyl chavicol (37.13%) in fosnutren and super-nitro plus, geranial (29.05%) and caryophylene (6.66%) in kadostim and nitroxin, and carvacrol (31.60%) in fosnutren and nitroxin treated plants. Conclusion: In general, the best treatment to improve growth and phytochemical traits of Ocimum basilicum were kadostim×nitroxin and fosnutren×nitroxin.