Impact of bilge water on seed germination and seedling growth of some vegetable plants

Abstract

In this study, the effect of bilge water on the germination and seedling growth of seeds of okra (Abelmoschus esculentus), tomatoes (Solanum lycopersicum) and garden egg (Solanum aethiopicum) at different concentrations (100, 75, 50, 25% v/v) was investigated. Bilge water was found to inhibit the germination of all the seed types used. The percentage germination, radicle length and plumule length of the seedlings decreased significantly (p<0.05) with increase in bilge water concentration. Seedlings cultivated in the wastewater developed toxicity symptoms but more chlorotic and necrotic regions were observed at higher concentrations. S. lycopersicum was least tolerant while A. esculentus was the most tolerant to the bilge water. The data obtained from physicochemical analysis of the wastewater revealed that it was acidic (pH5.11) and most of the heavy metallic contents were higher than allowable FEPA limits for effluent discharge. The results suggest that germination inhibition and poor seedling growth are probably due to strong tendencies of the plant species to accumulate the trace and heavy metals in the growth medium.