## 3 Results  
### Flour Quality  
The flour color was negatively correlated with the crude ash content (Table S6). The crude ash content of flour was positively correlated with weather conditions during grain ripening (Selyaninov index in BBCH 73-89) (Figure 1a). In turn, a negative correlation was noted between the flour color and the Selyaninov hydrothermal index during grain ripening (Figure 1b). A dry spell during grain ripening decreased the crude ash content of flour, which had a positive impact on the flour color. As a result, significantly lighter flour (79.9% of the whiteness standard) with a lower crude ash content (6.3 g kg\({}^{-1}\) DM) was obtained from winter wheat grain produced in a growing season with the least favorable weather conditions during grain ripening (2019/2020) (Tables 1 and S4). The total protein content and water absorption capacity of flour were positively correlated with the crude ash content (Table S6). Therefore, the total protein content and water absorption capacity of flour were higher in years when weather conditions promoted crude ash accumulation (humid and wet spells during grain ripening). The highest total protein content (135 g kg\({}^{-1}\) DM), the highest crude ash content (7.4 g kg\({}^{-1}\) DM), and the highest water absorption capacity (62.2%) were noted in flour obtained from grain harvested in the first growing season (2018/2029) (Table 1). The color of flour was significantly influenced by the sowing density and split spring N rate (Table S5). Lighter flour (78.2%) was obtained from grain grown in plots with the highest sowing density (400 grains m\({}^{-2}\)) (Table 1). Dense sowing exerted the most beneficial effect on the flour color in the first growing season (Figure 2). A lighter color was also obtained in 70 + 70 and 100 + 40 kg N ha\({}^{-1}\) (Table 1). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Parameter** & \begin{tabular}{c} **Crude Ash Content** \\ **(g kg\({}^{-1}\) DM)** \\ \end{tabular} & \begin{tabular}{c} **Color (\% Whiteness** \\ **Standard)** \\ \end{tabular} & \
\begin{tabular}{c} **Total Protein Content** \\ **(g kg\({}^{-1}\) DM)** \\ \end{tabular} &
\begin{tabular}{c} **Water Absorption** \\ **Capacity (\%)** \\ \end{tabular} \\ \hline \multicolumn{5}{c}{Growing season} \\
2018/2019 & 7.4 \({}^{\text{a}}\) & 76.9 \({}^{\text{b}}\) & 135 \({}^{\text{a}}\) & 62.2 \({}^{\text{a}}\) \\
2019/2020 & 6.3 \({}^{\text{c}}\) & 79.9 \({}^{\text{a}}\) & 127 \({}^{\text{c}}\) & 57.7 \({}^{\text{c}}\) \\
2020/2021 & 6.6 \({}^{\text{b}}\) & 77.1 \({}^{\text{b}}\) & 129 \({}^{\text{b}}\) & 59.2 \({}^{\text{b}}\) \\ \hline \multicolumn{5}{c}{Sowing date, mean for 2018–2021} \\ Early & 6.8 & 78.0 & 129 \({}^{\text{b}}\) & 59.2 \({}^{\text{b}}\) \\ Delayed (+14 days) & 6.7 & 77.9 & 130 \({}^{\text{b}}\) & 59.5 \({}^{\text{ab}}\) \\ Delayed (+28 days) & 6.7 & 77.9 & 132 \({}^{\text{a}}\) & 60.3 \({}^{\text{a}}\) \\ \hline \multicolumn{5}{c}{Sowing density (live grains m\({}^{-2}\)), mean for 2018–2021} \\
200 & 6.8 & 77.9 \({}^{\text{b}}\) & 132 \({}^{\text{a}}\) & 59.6 \\
300 & 6.8 & 77.8 \({}^{\text{b}}\) & 130 \({}^{\text{ab}}\) & 59.4 \\
400 & 6.7 & 78.2 \({}^{\text{a}}\) & 129 \({}^{\text{b}}\) & 60.0 \\ \hline \multicolumn{5}{c}{Split spring N rate (kg ha\({}^{-1}\)), mean for 2018–2021} \\
40 + 100 & 6.8 & 77.8 \({}^{\text{b}}\) & 132 \({}^{\text{a}}\) & 59.7 \\
70 + 70 & 6.7 & 78.0 \({}^{\text{ab}}\) & 130 \({}^{\text{ab}}\) & 60.0 \\
100 + 40 & 6.7 & 78.1 \({}^{\text{a}}\) & 129 \({}^{\text{b}}\) & 59.3 \\ \hline \hline \end{tabular}  
* Means with the same letters do not differ significantly at \(p\leq 0.05\) in [PERSON]’s test. Means without letters indicate that the main effect is not significant.  
\end{table} 
Table 1: Quality parameters of winter wheat flour. Figure 1: Linear regression between the crude ash content (**a**) and color of flour (**b**) vs. the Selyaninov hydrothermal index during winter wheat grain ripening. \({}^{\text{*}}\) significant at \(p\leq 0.05\); \({}^{\text{**}}\) significant, \(p\leq 0.01\).