2.5. Statistical analysis
The data of dry matter yield, heavy metal concentrations, and root:shoot ratios of plants under different treatments were analyzed using a SPSS statistical package (version 11.0.0, SPSS Inc., Chicago, Illinois). One-way analysis of variance (ANOVA) was carried out to compare the means of different treatments where significant F value was obtained, differences between individual means were tested using Duncan’s Multiple Range Test at 0.05 significance level.