To explain the high concentrationin the lower part we have to consider the early growth and development of corm. For vegetative propagation of our planting materials, we use headsets (the uppermost part of corm together with
parts of the petioles). The initial concentration of Ca in this partis low, however, this is the part which develops the first roots (successively becomes the lower or basal part), enabling the beginningof the absorption of Ca and other minerals. As Ca is not a mobilemineral, it starts accumulating.