Fig. 5.

Leaf elongation in four cultivars with impeded roots compared with roots in mechanically weak sand (control). Data are means for the two experiments estimated by fitting a spline function to the data from both experiments. The standard error of differences (SED) from REML analysis is shown. The interaction between cultivar, leaf number, time was significant at P < 0.001 (18 df) and the main effect of root impedance and cultivar had a significant effect at P < 0.001