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/N2‐O2 surface‐wave microwave discharges at 2–8 mbar pressure. It is shown, that the germination and vigour of non‐infected seeds are not significantly effected, when barley is treated max 120 s at 2 mbar and maize 240 s at 4 mbar. 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 3 min Ar‐20%O2 afterglow at 4 mbar, while for maize the 4 min Ar‐20%O2 + 2 min N2‐2%O2 at 8 mbar. The high NO content mixtures and the heating of seed surface by the recombination of O and N‐atoms inhibit barley germination. It is shown, that the afterglow of Ar/N2‐O2 low pressure surface‐wave microwave discharges do not effect significantly the germination and vigour of barley and maize seeds, when treated for less than 120 and 240 s, respectively. However, afterglows make possible to disinfect seeds from the germination inhibitors F. graminearum and F. verticillioides at well defined conditions.