Baking quality of winter wheat (Triticum aestivum l.) is influenced by fractionation of nitrogen fertilization

Despite nitrogen fertilization is one of the most commonly applied practices to wheat cultivation in order to increase yield and protein content, effects are found to vary significantly [1]. In addition, the relative contributions of both the total applied N as well as the fractionation of fertilization treatments on the protein composition are not fully elucidated. To gain a basic understanding of these effects under Western European growth conditions, samples from a field trial comprising 5 winter wheat (Triticum aestivum L.) cultivars fertilized with 3 N-rates (advice, -30% and +30%) applied in 3 or 4 fractions were studied on their yielding and kernel properties, wholemeal and flour composition and functionality. Flour quality was ultimately tested by baking trials and an elaborate screening of the bread quality. A significant interaction between total N and splitting was observed for both yield and protein content whereas protein composition (i.e. gluten index, Farinograph water absorption, and Alveograph P/L) was solely influenced by the fractionation. Applying N in 4 fractions resulted in an overall 3.7% increase in loaf volume compared to 3 N-fractions. Principal component analysis, however, illustrated the major contribution of starch-related properties to end-product quality of bread as well as the prominent genotype-effect which was found throughout the study.