The toxic effects of Paint, Battery and Textile effluents respectively on Vigna unguiculata (L.) Walp (Cultivar It 84 E-124) were evaluated in this study. Viable seeds were planted in 25, 50, 75% and neat (undiluted) effluents. Distilled water was used as control. The Physico-chemical characteristics of the effluents were analyzed. Heavy metals such as Zinc being 35.6 mg L-1 in Paint effluent, copper and lead were 10.5 mg L-1 in Battery effluent were found to be above Federal Environmental Protection Agencys limit suggesting toxic impact on the seedling. Leaf size, stem length and root length were observed to be responsive to the concentration gradient of the effluents. Dry weight declined with a positive response from mean value of 1.18 g for 25% Textile to 0.11 g for 25% Key paint. The test plant indicated high concentration of heavy metals in its biomass, for instance, 75% flash battery with highest fresh weight of 1.75 g except for textile effluent with 1.45 g. Textile effluent was also found to favour chlorophyll formation leading to photosynthesis while the other effluents were found not to be in favour of chlorophyll production. The mean total chlorophyll for control is 56.43 mg g-1, Undiluted Textile being 51.45 mg g-1, while Key paint has 9.11 mg g-1. Howbeit, the severity of toxicity of the industrial effluents follow this trend; key paint higher than flash battery which is higher than textile at the different treatment concentrations of 25, 50, 75% and neat (undiluted). Suggesting that at very low concentration, Vigna unguiculata thrives better in textile effluents contaminated environment than battery and paint effluents. It is suggested that these parameters in cowpea may constitute methods of environmental monitoring.
E.O. Oladele, P.G.C. Odeigah and T. Yahaya, 2011. Toxic Effects of Three Industrial Effluents on Growth and Development of Vigna unguiculata (L) Walp (Cultivar it 84 E-124). Journal of Biological Sciences, 11: 320-325.