Fig. 1

Plot layout in which the large rectangular area is considered the extent of the plot (1 m × 5 m). The five circles suggest the location of the cassava plants found in the plot, and the directional arrow suggests the movement of the ground penetrating radar antenna. Scan line spacing was set at .05 m in the X. The sampling interval was based on a manufacturer’s established setting for which a new pulse is emitted every .013 m in the Y as established by a calibrated measuring wheel attached to the unit