Thus, Ariefdjohan et al. (2004) found
that pressurised (275–575 MPa) alfalfa seeds at 40 C for 2 min
or 475 MPa for 2–8 min took longer to germinate, achieving germination
rate of up to 34%, while 95% of the control seed germinated.
The authors observed under a light microscope that the coats of
treated seeds were damaged, showing cracks or completely broken
seeds. Wuytack, Diels, Meersseman, and Michels (2003), reported
higher germination rates when seeds immersed into sterile water
were pressurised compared to dried seeds, effect attributed by
the authors to the fact that their seed coat is softened by the water,
alleviating the damage by pressure and improving therefore the
germination of seeds.