The Role of Amino Acid (Arginine) and Humic Substances in the Growth Traits and Chemical Content of Carissa carandas L. plants

Abstract

This study was conducted in one of the greenhouses of the College of Agriculture / University of Anbar, to study the effect of adding humic substance and spraying with arginine on the vegetative and root growth of the Carissa plant. The experiment included two factors: the first factor was the humic substance at four concentrations, which are 0, 1, 2, 3 milligrams per liter, and the second factor was the amino acid arginine at three concentrations, 6, 3, 0 milligrams per liter. The experiment was designed using a Randomized Completely Block Design (R.C.B.D) with three replications and 3 pots for each experimental unit, with each block consisting of 12 treatments and a total of 108 pots for all blocks. The results of the study summarized the presence of a significant increase in the interaction treatment between arginine at a concentration of 6 milligrams per liter and humic substance at a concentration of 3 milligrams per liter in the rate of surface area, the rate of increase in the number of branches, secondary branch diameter, phosphorus and potassium ratio to nitrogen, relative content in the leaves, reaching 1.343 cm2, 11.333 branches plant-1, 12.000 mm, 0.343%, 1.863%, and 1.390 mg g-1 respectively. Whereas, the control treatment exhibited the lowest rates in all of the aforementioned traits.