Effect of the afterglows of low pressure Ar/N2-O2 surface-wave microwave discharges on barley and maize seeds

Non-infected and infected cereal crops, respectively, are treated in the afterglow of Ar/N-2-O-2 surface-wave microwave discharges at 2-8mbar pressure. It is shown, that the germination and vigour of non-infected seeds are not significantly effected, when barley is treated max 120s at 2mbar and maize 240s at 4mbar. On the other hand, seeds can be disinfected from the germination inhibitors Fusarium graminearum and Fusarium verticillioides. The most efficient treatment, which also increases the germination of infected seeds above 80%, for barley is the 3min Ar-20%O-2 afterglow at 4mbar, while for maize the 4min Ar-20%O-2+2minN(2)-2%O-2 at 8mbar. The high NO content mixtures and the heating of seed surface by the recombination of O and N-atoms inhibit barley germination.