Effects of Certain Heavy Metals on Selected Growth and Yield Characteristics of Chili Pepper plants (Capsicum annuum L.)

Abstract

The objective of this study was to compare the reactivity of two genotypes of chili pepper (Capsicum annuum L.) to potential negative toxic effects of heavy metals (lead, cadmium and nickel) on specific growth and yield characteristics. The study was performed from March 15, 2025, to November 1, 2025. The experiment was developed using a Randomized Complete Block Design (R.C.B.D.) with three replications and two factors: the first factor consisted of the two genotypes of chili pepper, and the second factor was concentrations of heavy metals: lead at three concentrations (80, 120, 160) mg kg⁻¹ soil by lead acetate, cadmium at three of (3, 4.5, 6) mg kg⁻¹ soil by cadmium sulfate, and nickel at three of (40, 60, 80) mg kg⁻¹ soil by nickel sulfate, with interactivity. Duncan’s multiple range test was used to compare the mean differences at a 5% significance level. The survey consisted of the plant height measurement, number of different branches, leaf area, and yield per plant. The study findings were that the differences between the genotypes were markedly significant, with the Cayenne genotype significantly outperforming the others for most of the traits performed in the study, with an average plant height of 53.50 cm, branch number of 2.28 branches per plant (and yield per plant = 78.16 g plant-1), and an average leaf area value of 18.77 cm² per plant were found to be significantly superior with the ID15 genotype. High concentration of heavy metals and interaction with these metals was found to affect the plant physiologic equilibration including synergistic toxicity, and influenced plants height, number of branches, leaf area and yield per plant. Toxic exposure to low metals, however, resulted in an antagonistic phenomenon allowing plant to continue to grow.