Evaluation of chitosan oligosaccharide as an alternative treatment to mitigate Fusarium graminearum and mycotoxin contamination in wheat

Fusarium head blight (FHB), caused by members of the Fusarium graminearum species complex, is one of the most serious wheat diseases worldwide, capable of causing severe yield losses and affecting grain quality. Methods available for FHB management include cultural practices, sowing of resistant cultivars, chemical control, and biological control. In the present study, we evaluated the effect of chitosan oligosaccharide on the control of fungal growth, seed infection, disease symptoms and mycotoxin contamination under both controlled environments and in the field. In the in vitro conditions, chitosan oligosaccharide directly affected fungal growth at different levels depending on the concentration used. When applied as a seed treatment, both tebuconazole and chitosan oligosaccharide reduced the incidence of F. graminearum and preserved seed germination potential of infected seeds. In the field, there was no significant difference in disease severity and DON in grains between the unsprayed check and the fungicide, regardless of the doses or times of chitosan oligosaccharide application. The results of this study suggest that chitosan oligosaccharide can potentially be used as a tool in the integrated management of the disease, establishing a basis for future studies to explore its use associated with chemical products, aiming to increase the efficacy of FHB control in wheat.