Effects of Tin Mine Tailings on the Growth and Development of Common Bean (Phaseolus vulgaris L.) in Jos, Nigeria

Aims: To study the effects of mine tailings on the growth and yield of two genotypes of common bean (Phaseolus vulgaris L.).

Study Design: The experiment was laid in a Randomized Complete Block Design (RCBD) with four treatments, two blocks and each block was replicated three times.

Place and Duration of Study: Botanical Garden, Department of Plant Science and Biotechnology University of Jos, Plateau State, Nigeria during the rainy season in a field experiment in 2014.

Methodology: The mine tailings combinations include four different additions mine tailings soil {(T0) 0 kg as control, (T1) 2 kg, (T2) 3 kg, (T3) 4 kg} and the respective mine tailings soils were added to 6.3 kg of normal soil. Two common bean accessions were used (Cranberry-G1 and Pinto-G2), which gave the total of eight treatment combinations (T0G1, T0G2, T1G1, T1G2, T2G1, T2G2, T3G1, T3G2).

Results: The control recorded significant higher mean plant height (cm), number of leaves and number of trifoliate leaves, number of pods and number of seeds per pod in both genotypes for all the different weeks after planting (WAP). A significant decrease in plant height, number of trifoliate leaves, number of leaves per plant, number of pods and number of seeds per pod in both genotypes were observed with increased levels of mine tailings. There was a significant increase in time to 50% flower and 50% pod production (P = 0.01) over the control which increased with increasing levels of mine tailings. The genotypes exhibited no significant difference (P = 0.05) for most traits accessed, except for number of pod per plant. It is evident from the findings that Cranberry is more tolerant to heavy metals contamination in soil, perhaps may be more suitable for planting in such mining soils.

Conclusion: The study showed that inclusion of mine tailings had detrimental effect on both the growth and yield of common bean.