At the sowing day the initial carbon content, cSeed, is planted. This does not yet affect any of the plant carbon pools and the seed is not assumed to have any respiration or photosynthesis.
At emergence (for plants starting at GSI < 1) the carbon content of the seed has to be allocated to the roots, stem and the leaves before the assimilation begins. Therefore, at GSI=1, the carbon content in the seed, cSeed, is allocated to the roots, leaves and stem using the same allocation equations as for allocation of assimilates (see eq. (5.37), (5.38) and (5.39)) by assuming that Ca corresponds to the carbon content in the roots, cSeed. If a root already exists at emergence (i.e. remaining from the previous season) no seed is planted. Instead the carbon content in the root is transferred to the seed and thereafter allocated to the stem, leaves and roots as described above.