The effects of soil cover and Stimplex (Ascophyllum nodosum extract) foliar application on antioxidant activity and some physiological characteristics of Coriandrum sativum L.

Abstract

Two field experiments were conducted as factorial based on randomized complete block design to study the effects of soil covering (black, white, control), location (Sarab and Shabestr, Iran), and Stimplex foliar application levels (0, 2, 4 and 6 ml L^-1) on growth and physiological traits of <em>Coriandrum sativum</em><em>.</em> The highest values for essential oil, flavonoids and nitrogen contents were recorded for black covering at 2 ml L^-1 foliar application of Stimplex. For phenolic compounds the highest values were observed with black covering at 2, 4 and 6 ml L^-1 of foliar spray. In the city of Sarab, maximum values of root dry weight and essential oil content were obtained with 6 and 2 ml L^-1 Stimplex spray, respectively. The best IC₅₀ belonged to the white and black soil covers in Shabestar (1.6 and 1.7 mg ml^-1, respectively). Foliar spray had significant effects on the above-ground biomass, plant height, axillary brunch number, umbel number, total soluble solids (TSS), phosphorus and potassium contents. Sarab had higher values than Shabestar for the nitrogen and potassium contents, axillary brunch number and TSS. Black soil cover had positive effects on K (%), P (%), TSS, chlorophyll a, umbel number per plant, plant height, axillary brunch number and above-ground biomass. In total, the results revealed that using black soil cover and foliar application of algal extract (2 ml.L^-1) improved the growth and physiological responses of <em>C. sativum</em> plants.