ABSTRACT

The effects of Lead on the growth and development of Glycine max was carried out. Lead treatments of 10ppm, 40ppm, 70ppm and 100ppm were used on 5 accessions of soya beans, a control plant for each concentration of the Soya beans was used. The outcome showed that lead has significant effects on the growth and development of soya beans (Glycine max). The control plants for the different accessions thrived, attaining an average stem length 87.2cm, the accessions treated with 10ppm of lead attained an average stem length of 78cm, accessions treated with 40ppm of lead attained an average stem length of 67cm, accessions treated with 70ppm of lead attained an average stem length of 59.8cm, and accessions treated with100ppm of lead attained an average stem length of 47cm. The average stem girth of the control plants was 3.4mm, accessions treated with 10ppm had an average stem girth of 3.04mm, 40ppm had an average stem girth of 2.82mm, 70ppm had an average stem girth of 2.50mm, 100ppm had an average stem width of 2.50mm. The average number of flowers produced by the control was 18, 10ppm produced 15, 40ppm produced 11, 70ppm produced 8 and 100ppm produced 6. The control plants produced an average of 11 pods, 10ppm produced 9, 40ppm produced 7 70ppm produced 5 and 100ppm produced 4. Chlorophyll content of the leaves was also affected by lead with control plants having an average total chlorophyll content of 27ccl and the highest concentration of 10ppm having an average of 10.44ccl after 7 weeks of the treatments. The lead treatments were found to inhibit the elongation of the stem of the plants and inhibit the growth of the stem width, reduce the chlorophyll content of the leaves, and reduce the number of flowers and pods produced, and generally affect the growth of the plant as the concentration increased. This study has demonstrated that Lead pollution has an inhibitory effect on the growth and development of plants and at concentrations too high it becomes lethal to plants.