Department of Plant Science and Biotechnology, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria
Recycling of organic-based wastewater for crop production has received worldwide acceptability as a promising alternative to fertilizer use. Hence, this research evaluated growth, yield and nutritional quality of tomato and sweet pepper irrigated with abattoir wastewater (AWW) with the aim of assessing recycling liquid effluent from slaughterhouses for crop production. Each vegetable was cultivated in experimental pots irrigated with 0 (control), 20, 40, 60, 80 and 100% AWW. In tomato, AWW improved plant height, number of branches and leaves, and relative growth rate (RGR) with the maximum values recorded at 100% AWW. Root and shoot dry mass, total biomass and root/shoot ratio were also increased in plants treated with undiluted AWW. In sweet pepper, values of plant height, number of leaves and branches, root length and RGR were higher under AWW treatments than the control with peak values recorded at 100% concentration. The root mass of sweet pepper was increased but the root/shoot ratio was reduced at all AWW concentrations with the highest impact found when AWW was not diluted. While AWW resulted in an increased number of fruits in both crops with the best performance when undiluted, the differences with control were only significant in tomato. Fresh and dry mass of fruit was also significantly increased by AWW in both crops with the highest values recorded at 100% concentration. AWW increased fruit nutrient and heavy metal contents of both vegetables but this increase was nonsignificant compared to control. In conclusion, the application of 20-80% AWW is capable of increasing tomato and sweet pepper production but growing them with undiluted AWW irrigation was the most effective alternative source of fertilizers for improved growth, yield and nutritional quality of vegetables.