Seed storage conditions and germination

It seems apparent that the seed moisture for storage is most critical to maintaining high germination percentage and initial root and shoot growth.  Temperature was a factor but moisture content in storage was critical.  Seed producers are aware of this concept and use many methods to monitor drying of seed after harvest, applying seed treatments and storing the seed. 
 
Higher moisture content in the seed activates some metabolism but not insufficiently to germinate effectively, causing an aging process.  The pericarp does help protect air moisture diffusion into the kernel but genotypes vary in this pericarp feature, potentially complicating the drying and storage of the seed. Each individual kernel being slightly different physiologically and structurally contributes to the difficulty in producing and maintaining high percentage germination quality until planting time.  Plant Physiol. 42, 1071-1076) compared seed respiration during imbibition, storage facility conditions, germination % and seedling growth of corn seed. Following table from that publication summarizes the interaction.

Research published in 1967 (Relationships Between Seed Respiration During Imbibition and Subsequent Seedling Growth in Zea mays L. 1 Lowell W. Woodstock and Don F. Grabe)