Brain and Cousens model more suitable.

<p>Dose-response relationships for effects of different phytotoxins and an aqueous leaf extract of <i>Parthenium hysterophorus</i> at the flowering stage on root growth of <i>Lactuca sativa</i> and their description by the hormetic dose-response models after Brain and Cousens <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033432#pone.0033432-Brain1" target="_blank">[9]</a> (grey curve) or Cedergreen et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033432#pone.0033432-Cedergreen1" target="_blank">[2]</a> (black curve). The Cedergreen et al. model <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033432#pone.0033432-Cedergreen1" target="_blank">[2]</a> did not detect significant hormetic responses (<i>f</i><0) (A–E) or provided an inferior fit (F). Error bars represent standard deviation. DM = dry leaf mass.