Effect of pulsed electric field on viability of Fusarium micromycetes

Fusarium species are one of the most studied fungal pathogens of cereals. They cause Fusarium head blight or stem base diseases that are risky not only in terms of yield losses but also due to mycotoxins production. Several strategies are used to prevent Fusarium colonisation of plants, including fungicide treatment. However, according to the EU Biodiversity Strategy for 2030, the use of fungicides needs to be reduced, and therefore, alternative seed treatments should be sought. One possible method is the use of a pulsed electric field (PEF) that could kill or remove the fungi from the grains surface. The sensitivity of fungi to PEF treatment was first investigated. Spore suspensions of four Fusarium species (F. culmorum, F. graminearum, F. poae, F. sporotrichioides) were treated in a continuous PEF system (OMNIPEF; VITAVE, Czech Republic), and spore viability was subsequently assessed on an artificial medium. Different species of the genus Fusarium showed statistically significant differences in their response to PEF. As the frequency increased from 450 to 900 Hz, the number of viable spores gradually decreased for all Fusarium species tested. Fusarium poae responded already at the lowest frequency of 450 Hz with a strong reduction in spore viability (only 9.4% of spores survived). At the same frequency, 15.3% of F. graminearum spores, 28.9% of F. sporotrichioides spores, and 53.4% of F. culmorum spores remained viable.