Fig. 2

The seed germination rate (A), germination energy (B), germination speed (C), mean germination time (D), and germination index (E) in H. syriacus treated with 30, 50, and 90 nm ZnO NPs at 0, 10, 50, 100, 500, and 1000 mg/L. Data are shown as mean ± standard deviation of three replications. Significant differences (p < 0.05) are indicated by column lines labelled with different letters according to Duncan’s test.