The effect of natural extracts and tea compost in some root growth parameters of Calendula plant under stress by heavy elements

A factorial experiment was carried out in one of the greenhouses to study the ability of the calendula plants to accumulate and resist growth in soil contaminated with toxic elements and plant treatment using plant extracts and treatment with different proportions of bio-organic aqueous extracts in some root growth indicators. The experiment included the use of three factors. The first factor included two types of plant extracts (licorice root and malt grain) in addition to the control treatment, while the second factor was treating the planting soil with two ratios of tea compost (1/5 and 1/10). The third factor was the treatment of Potting soil with the heavy elements copper and lead and their mixture at a concentration of 5 mg kg-1, the experiment applied according R.C.D with three replicate, and each replicate included 3 experimental units. The results of the study showed a significant impact in the characteristics of the root growth. The intervention treatment (malt extract and a 1/5 ratio of tea compost for calendula plants stressed with two elements lead and copper and those not stressed) had a significant advantage in root length and the number of roots with an average of 39.33 cm and 16.67 roots, respectively. While the interaction treatment (licorice extract not treated with tea compost and stressed with copper) achieved an average of 3.292 gm for the dry weight of the root system, the two triple interaction treatments (malt extract, not treated with tea compost and stressed with lead, and treated with licorice extract, not treated with tea compost and stressed with copper) achieved an average of (44.66, 16.320) mg kg soil-1 root content of lead and copper.