Scanning electron microscopy (SEM) of maize root segments treated with CaCl
with humic-like acids from vermicompost. (A) 2-mM CaCl2. (B) 2-mM CaCl2 plus 50 mg L−1 humic-like acids. Bars = 100 μm (Adapted from Canellas et al. ). Other evidence of root hair induction by HS can be observed in SEM of wheat .