Fig. 2.

Percent of germinated seeds forming cotyledons in seeds of three agricultural species as a function of concentrations of 12 mobile organic compounds identified in biochar leachates. Symbols represent the mean of 3 replicates: open (black) circles with solid line are lettuce; open (blue) squares with dotted line are ryegrass and closed (red) circles with dashed line are radish. Fitted curves are for the logistic model (Eq. 1) with the upper asymptote parameter (c) fixed to zero