The influence of foliar application of nano zinc chelate and zinc sulfate on morphological traits of holy basil (Ocimum sanctum)

Holy Basil is a perennial shrub plant that belongs to Lamiaceae family. Aerial parts of this plant have been used in food, pharmaceuticals, cosmetics and perfumery industries. Leaves of this plant contain 0.5-1.5% essential oil and main oil components are eugenol, methyl eugenol, carvacrol, estragol, and eucalyptol. In order to evaluate the effect of foliar application of zinc fertilizer on morphological traits of holy basil, an experiment was conducted in research farm of Department of Horticultural Science, Shahid Chamran University of Ahvaz based on randomized complete block design with six treatments and three replications. The treatments were nano zinc chelate (0, 0.5, 1 and 1.5 gr.lit-1) and zinc solfate (1 and 1.5 gr.lit-1) fertilizers. Foliar application of fertilizer was done at six or eight leaf stage and was repeated with an interval of 15 days until the end of the study. Morphological traits includingplant height, branches number, leaf number, leaf size (length and width), leaf area, stem diameter, main inflorescence length, inflorescence number, fresh and dry weights of leave, stem and aerial parts were measured at full bloom stage. The results showed that the effect of foliar application of zinc fertilizers on all measuredmorphological traits of holy basil was significant (p≥0.01). The highest and lowest values of mentioned traits were obtained in plant sprayed with 1.5 gr.lit-1 nano zinc chelate and control, respectively. Overall, given the non significant difference between 1 and 1.5 gr.lit-1 treatments, to increase morphological traits of holy basil, foliar application of nano zinc chelate with 1gr.lit-1 is recommended.