A manufactured seed that comprises: (a) a seed shell (20) housing a nutritive medium (26) (b) a cylcap (22), which is a restraint having a cavity (32) disposed within the seed shell (c) a totipotent plant embryo (42) disposed within the cavity of the cylcap (d) a fill material (120) disposed within the cavity of the cylcap and (e) a seal disposed (43) on the seed shell to seal the embryo with the seed shell. The fill material is an adsorbent material that increases the surface area of the plant embryo that is in functional contact with the nutritive medium. The fill material can be activated charcoal.
