Effect of terracottem superabsorbent and Plantago ovata mucilage on some morphological, biological properties, water use efficiency and essential oil in Ocimum basilicum L. var. "Keshkeny levelu"

One of the most important limiting factors in production of medicinal plants in arid and semiarid regions of the world is water shortage or drought stress. Basil (Ocimum basilicum L. var. "Keshkeny levelu") is a valuable medicinal plant and sensitive to water stress. Therefore, the current study was aimed to increase water use efficiency in basil production by conducting a factorial experiment based on randomized complete blocks design with three replications. The treatments were two superabsorbent polymers namely Terracottem™ (industrial) and Plantago ovata mucilage (Herbal) at four concentrations (0, 0.1%, 0.2% and 0.3% w/w on the basis of soil weight) with two application methods (mixed with soil only and mixed with soil+roots). The measured traits were morphological: leaf number, leaf area, shoot to root ratio, biological: number of seeds/plant, seed weight/plant, and water use efficiency, as well as two other important characteristics such as essential oil percentage and yield at flowering time. Results showed that the simple effect of treatments and their interaction had significant and positive effects on morphological, biological and biochemical traits, measured in this experiment. The best results in vegetative and generative characteristics were obtained by application of Plantagoovata mucilage and the highest essential oil percentage and yield were recorded by using Terracottem superabsorbent. The best results in both compounds were obtained at concentrations of 0.1% and 0.2% with application method in soil+roots and soil only, respectively. In conclusion, both compounds (terracottem™ and Plantago ovata) were able to reduce the adverse effects of drought stress and improved water use efficiency in basil cultivation.