Reduction of Microbial Load on Radish (Raphanus sativus L.) Seeds by Aqueous Chlorine Dioxide and Hot Water Treatments

This study was conducted to investigate the effect of treatment with squeous chlorine dioxide and hot water on the germination of radish (Raphanus sativus L.) seeds, and reduction of microbial load on the seeds. Increases in treatment and the concentration of aqueous chlorine dioxide in water resulted in increasing reductions in the counts of total aerobic microbes. Seeds treated with aqueous chlorine dioxide (100 ppm/20min, 200ppm/20min) showed about a 10-fold decrease in microbial loads. Germination of seeds was not adversely affected by any treatment tested, although the germination rate of seeds in the group treated at for 20 min was reduced by 10% compared to that of control. Combined treatment with hot water and aqueous chlorine dioxide yielded better out comes in both microbial reduction and seed germination rate than did single treatments. A combined treatment with 100 ppm aqueous chlorine dioxide and hot water( or ) resulted in about a 100-fold decrease in microbial load whereas germination rate showed only a slight increase to . Total aerobic microbial counts in radish seeds were decreased by aqueous chlorine dioxide and hot water treatment in the order. aqueous + hot water > aqueous > chlorinated water > hot water > control.