Fig. 3

Effect of variable doses (control having Cd–Cr but no B = 0 g), 50, 100, 150 and 200 g) of spent mushroom substrate derived biochar (B) on maize ascorbate peroxidase (APX) (A), glutathione reductase (GR) (B) and glutathione (GSH) (C) cultivated under chromium and cadmium toxicity. Bars are means of 3 replicates ± SE. Variable bar letters showed significant changes at p ≤ 0.05 compared by Fisher’s LSD.