Cover Image

Effects of Sewage Effluent on the Yield and Quality of Celosia Argentea L. (Lagos Spinach)

Nkechinyere Onyekwere Nweze, Helen Takwa


The aim of this study was to assess the effects of irrigation with sewage effluent on the yield and quality with age of potted Celosia argentea plants, grown on garden soil amended with poultry manure, using tap water as control. The concentration of some heavy metals (Lead, Arsenic, Cadmium, Mercury, Nickel and Zinc) in the sewage effluent, and tap water were analyzed before use. Growth and yield attributes (height, wet and dry weights, leaf number and area) and heavy metals content of potted Celosia plants were assessed fortnightly for twelve weeks in a screen house. Data obtained were subjected to analysis of variance (ANOVA). The sewage effluent had higher concentration (µg/L) of Lead (0.822), Arsenic (0.136), Cadmium (0.106), Mercury (0.722) and Nickel (0.026). Cadmium, Mercury, and Arsenic in tap water and sewage effluent were above WHO/FAO limits for irrigation water. Sewage effluent significantly (P ≤ 0.05) promoted the yield attributes more than tap water. The maximum values for leaf area, number of leaves, height and dry weight were 104 cm2, 25, 65 cm and 23.91g respectively. Concentrations (µg/L) of Nickel (0.02 – 0.87) and Zinc (0.24 – 1.49), were within WHO/FAO safe limit for human consumption, while Lead (0.27 – 0.89 µg/L), Cadmium (0.25 - 0.88), and Mercury (0.020 – 0.087) were not. The concentration of the heavy metals increased with the age of the plants, especially in the edible part (leaves) after eight weeks; hence, it is safer to consume this vegetable plant at the tender age of four to six weeks.


  • There are currently no refbacks.