Effect of Mixture of Lead and Zinc on the Growth and Development of Vernonia amygdalina Del.

Abstract

The effect of the mixture of lead and zinc (1:1) on the growth and development of Vernonia amygdalina Del was investigated. The plant was grown from stem cuttings in buckets (each with 5 kg dry soil) and was allowed to stabilize for a month before being treated with the mixture of lead and zinc. The experiment was made up of control and four concentrations (25, 50, 75 and 100 mg/kg) in three replicates. Data were collected monthly for 12 months for plant height, leaf area, number of branches and girth. Results revealed an adverse effect of treatment. Data recorded for number of leaves were 35.67±7.53, 19.67±4.63, 23.00±1.52, 25.33±4.48 and 21.67±5.54 for the control and four treatments (25, 50, 75 and 100 mg/kg) respectively. Girth values obtained at the experiment for the control, 25, 50, 75 and 100 mg/kg treatments were 15.71±0.00, 11.00±0.90, 12.57±0.00, 14.14±0.90 and 12.57±1.81mm respectively. There was significant difference between height and girth of control and the treated plants. Treatment also resulted in a decrease in soil pH, nutrient element composition of soil and soil microbial population. It however caused an increase in soil carbon. The plants took up more lead than zinc.