The effect of laundry grey water irrigation on the growth response of selected local bean species in Nigeria

B. Ikhajiagbe1,2, E.O. Ohanmu1,3*, P.O. Ekhator1, P.A. Victor1

1Environmental Biotechnology and Sustainability Research Group, Department of Plant Biology and Biotechnology, University of Benin, Benin City, Nigeria
2Applied Environmental Biosciences and Public Health Research Group, Department of Plant Biology and Biotechnology, University of Benin, Benin City, Nigeria

3Department of Biological Sciences, Faculty of Science, Edo University Iyamho, Edo State, Nigeria

(Manuscript received 25 July 2019; accepted for publication 5 February 2020)

Abstract. This study examined the growth responses of some selected local bean (pulses) varieties in Nigeria; Vigna unguiculata (Ife brown), Vigna unguiculata (Ekpoma Local), Phaseolus vulgaris, Cajanus cajan and Glycine max, cultivated on soil irrigated with laundry-based grey water. Healthy seeds of all bean species were sown in plastic bowls of three replicates each and irrigated daily with similar quantities of the respective grey water. The effect of the grey water on the germination, growth and yield of all the beans was observed for a period of four months. The result obtained revealed that grey water had a negative effect on the growth and yield of all the beans as there was a decrease in the percentage emergence of all seedlings, height of emergent seedlings and number of flowers and pods produced. Grey water also altered the chlorophyll content and total crude protein of all the beans subjected to the treatment. The effect of grey water on plant is as a result of accumulation of excess salts contained in grey water on the soil.