The efficacy of non-equilibrium dielectric barrier discharge in air on the elimination of phytopathogenic fungi from wooden surface

Abstract

Despite the use of modern transport and storage techniques, post-harvest losses of fruit and vegetables due to diseases are a major global problem. Therefore, it is necessary to stop or prevent the development of infectious diseases at all stages of plant production. In response to this problem, we proposed an atmospheric plasma with a dielectric barrier discharge (DBD) in air as a biocidal technique for the eradication of phytopathogens: Fusarium oxysporum, Alternaria alternata, and Botrytis cinerea. The reactor used in our experiments generates UV photons, electrons, ions and reactive oxygen/nitrogen species, which are highly effective as biocidal agents. The effectiveness of eliminating these fungi using DBD plasma was initially studied on artificially inoculated wooden discs and it was shown that plasma treatment for 3 min (27 ± 13) s, 5 min (32 ± 7) s, and 9 min (53 ± 30) s resulted in the destruction of 90% of F. oxysporum, A. alternata, and B. cinerea, respectively. Extending the treatment time to 20 min was sufficient to cause a lethal effect on fungi naturally contaminating the surfaces of wooden storage boxes. Plasma treatment induced damage to the cell envelope and stimulated the formation of intracellular ROS, leading to leakage of cytoplasmic contents and ultimately cell death. It was confirmed that multiple exposures of these microorganisms to plasma did not induce fungal resistance to this disinfection method.