Fig. 3
Effects of Cd [0 mg/kg (control) and 150 mg/kg CdNO3] on maximum quantum efficiency of photosystem II (Fv/Fm) (A) and performance index on absorption basis (Pi-ABS) (B) of lettuce plants over 8 weeks after sowing and treatment with water, sulfate reducing bacteria (SRB), Spirulina (SP) and co-application of SRB and SP (SRB + SP). Each column represents the mean value of three replications ± standard error. Different letters indicate a significant difference between the means at the probability level of P < 0.05.
