The impact of silo-bag storage on Fusarium diversity, mycotoxin contamination, and grain deterioration in bread wheat...

Fusarium head blight (FHB) is among the primary diseases of wheat, which affects grain quality that is essential for ensuring food safety and industrial value. The present study evaluated the effect of post-harvest silo-bag storage on fungal diversity, mycotoxin contamination, and physiological grain deterioration over two growing seasons. Field assessments were performed during the crop cycle, and fungal colonies were characterised at the beginning and after six months of bagging where O₂ and CO₂ were measured. Mycotoxin levels and grain physiological parameters, including germination and vigour, were also measured. Results showed a high prevalence of Alternaria spp., with Fusarium spp. as secondary colonisers, and species composition varied by genotype and storage time. Silo-bag storage increased CO₂ concentration compared with normal atmospheric conditions, limiting fungal proliferation without significant changes in pH. Deoxynivalenol (DON) was the most frequently detected mycotoxin with a maximum content of 279.36 ppb after bagging in 2021 for the Nutria genotype, while other toxins were detected sporadically. Grain physiological parameters declined during storage largely independently of fungal diversity or mycotoxin contamination, suggesting intrinsic biochemical deterioration processes. These findings emphasise the potential interactions between Fusarium spp. and Alternaria spp. during the bagging process, depending on wheat genotype, year, and their interaction. Overall, the fungal proliferation and the mycotoxin contamination should be considered for improving wheat post-harvest management to ensure the safety and quality of stored grain.