Bactericidal effect of intense pulsed light on seeds without loss of viability.

This study investigated the microbial inactivation effects of intense pulsed light (IPL) treatment as an alternative to chemical treatment for decontaminating the radish and pak choi seeds. The f R values (which indicate the resistance to IPL treatment) for radish and pak choi seeds were 24.50, 20.81 J/cm2, respectively. This resistance exhibited by seeds to IPL treatment is related to their surface roughness. Their Rq (the root-mean-square roughness), average surface roughness (Ra), and 10-point height roughness (Rz) values indicate that each crevice on a rough surface could shelter microorganisms from IPL. Viability tests of seeds exposed to IPL treatment indicated that the average germination rates of treated seeds exceeded 85% on day 3 of germination, which is considered as an acceptable criterion for germination. Also, on day 5 of germination the average shoot lengths of sprouts exposed to IPL did not differ significantly from those of untreated seeds.