Elongation and shape formation of the main root are
the objectives of the current analysis. We start the
following simplification of the theory for model
construction. First, the total shape of the root is
determined as a result of dynamic contact interactions
between the root and surrounding soils. Second, in the
growth stage of the root, sufficient energy for root
growth is continuously supplied by the conversion of
nutrients or by photosynthesis. Third, the root cap is
the most influential part of the root to direct the
orientation of elongation, which is followed by the
elongation zone, where the change in length of the
root is mainly generated.