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Poster: Biology & Disease Mgmt: Chemical Control


Antibacterial potential of Magnesium oxide nanomaterial against Xanthomonas perforans causing bacterial spot of tomato
Y. LIAO (1), A. Strayer (1), . White (2), A. Mukherjee (2), W. Elmer (3), L. Ritchie (4), D. Clark (4), J. Freeman (4), J. Jones (1), M. Paret (4) (1) Department of Plant Pathology, University of Florida, U.S.A.; (2) Department of Analytical Chemistry, Th

Bacterial spot caused by Xanthomonas perforans can cause high disease severity on tomatoes in Florida. Due to the presence of copper (Cu)-tolerant X. perforans strains, copper-bactericides are of limited use; thus, there is a critical need for finding effective alternatives. In this study the antibacterial activity of magnesium oxide (MgO) and other metal oxide nanomaterials were evaluated against Cu-tolerant and sensitive X. perforans strains. In vitro assays demonstrated that MgO had high antibacterial ability compared to the equivalent concentration of a Cu-based bactericide against both strains. A greenhouse experiment demonstrated that disease severity was significantly reduced by MgO at 200 ppm compared to copper-mancozeb, the grower standard and the untreated control (p = 0.05). A field experiment demonstrated that the same treatment significantly reduced disease severity compared to the untreated control (p = 0.05). There was no significant difference in the yield between the treatments. Inductively Coupled Plasma Mass Spectrometry analysis of the fruits showed that MgO treatments did not lead to significant accumulation of Mg, Cu, Ca, K, Mn, P and S compared to the untreated. However, copper-mancozeb treatment led to significant accumulation of Cu and P compared to the untreated control (p = 0.05). This study shows the antibacterial potential of MgO nanomaterials against X. perforans and its potential use against bacterial spot of tomato.