Hard seeds in beans: Proper temperature and humidity during storage important for germination
James F. Harrington, Experiment Station, Davis
California Agriculture 2(10):4-12. DOI: 10.3733/ca.v002n10p4.
James F. Harrington is Assistant Professor of Truck Crops and Assistant Olericulturist in the Experiment Station, Davis.
Not available – first paragraph follows:
Hard seeds have seed coats which retard the entrance of moisture into the seed. Seeds with hard coats are slow to swell. Since water is necessary for germination seeds do not germinate so long as they remain hard.