Effects of sowing date, nitrogen fertilization, and Fusarium graminearum in an Argentinean bread wheat: Integrated analysis of disease parameters, mycotoxin contamination, grain quality, and seed deterioration

Bread wheat is one of the main crops cultivated worldwide that can be affected by fungal diseases as Fusarium head blight. The aim of this work was to analyze the effect of sowing date and nitrogen fertilization on the F. graminearum-wheat interaction. The experiment was carried out involving two sowing dates with different nitrogen fertilization and F. graminearum inoculation treatments. A total of 32 variables related to the disease parameters, mycotoxin production, grain quality, gluten composition, and seed deterioration were evaluated. Disease severity was significantly increased after F. graminearum inoculation (2.2-fold) while mycotoxin production increased significantly for the delayed sowing date: deoxynivalenol (3.2-fold), 3-ADON (3.6-fold), nivalenol (8-fold), and zearalenone (5-fold). Regarding grain quality, the delayed sowing date showed a decrease in the protein percentage (-15 %) and gluten concentration (-17.9 %), while an increase of test weight (+6.2 %) was observed. Seed deterioration variables showed differences among longevity parameters showing an increase in seed vigor and viability in the late sowing date. In conclusion, sowing date and nitrogen fertilization could affect FHB severity, mycotoxin contamination, and grain quality.