Growth and development of bitter leaf (Vernonia amygdalina Del.) in soils treated with mixture of cadmium and lead

Abstract

The effect of treatment with cadmium and lead (mixed in a 1:1 ratio) on the growth and development of Vernonia amygdalina Del. was investigated. The plant was grown from uniform green cuttings in buckets (each with 5kg dry soil) and allowed to stabilize for a month before being treated with the mixture of metals. The experiment was made up of control and four concentrations (25, 50, 75 and 100 mg/kg) of the metals in each mixture. Data were collected monthly for 12 months. Result on plant height, number of leaves, and number of branches and girth of stem revealed an adverse effect of treatment at the end of the experiment except leaf area which was enhanced. Values for number of leaves 35.67±7.53, 14.00±4.35, 12.33±0.88, 0.00 and 0.00 were recorded for control, the 25, 50, 75 and the 100 mg/kg treatments respectively,. There was decreased soil pH, microbial load and nutrients but an increase in soil carbon. The effect increased along the concentration gradient. There was more uptake of lead than cadmium.

Keywords: Treatment, growth, nutrient, cadmium, lead, Vernonia amygdalina