## 3 Results and Discussion
### Grain Quality and Flour Yield
According to [PERSON] et al. [25] vitreousness grains are characterised by a higher degree of endosperm content, and higher grain hardness and protein content in comparison with non- vitreous grain. The grain vitreousness of the tested cultivars ranged between 40.0 and 77.0%. Significantly, the highest grain vitreousness for both doses: N\({}_{1}\) and N\({}_{2}\) were found in the Hymalaya and Hyventohybrid cultivars, which at N\({}_{1}\) fertilisation, were characterised by a higher value of this parameter than the Hybery, Hyfi, Hypocamp, Belissa, and Honda cultivars fertilised by N\({}_{2}\). Compared to N\({}_{1}\), N\({}_{2}\) resulted in a significant increase of grain vitreousness, by 23.0 and 25.0% only in the Hyena and Hykinghybrid cultivars. An appropriate content of total protein, which is not only determined by nitrogen fertilisation, but also by genetic predispositions, is the basic factor determining the applicability of wheat cultivar grain for bread baking [10; 26; 27]. Crude protein content in the grain ranged between 11.8 and 14.2% (hybrid cultivars) and between 11.4 and 13.3% (population cultivars). Similarly to a study by [PERSON] and [PERSON] [3], the present study confirmed increased protein content in the grain with increased N dosage for all cultivars. However, the cultivars reacted differently to this effect [9]. The Hyfi and Hyking cultivars fertilised with N\({}_{1}\) had a crude protein content at the same level as the Hybery, Hypocamp and Belissa cultivars fertilised with N\({}_{2}\). Also [PERSON] et al. [28] indicated the effect of the interaction of wheat cultivars and different levels of N fertilisation on protein content of the grain. Increasing the dose from N\({}_{1}\) to N\({}_{2}\) resulted in a significantly higher crude protein content in the grain of the Hyena and Hykinghybrid cultivars, at the level determined in the grain of the Hondaipopulation cultivar. The highest crude protein content (N\({}_{2}\)) was determined in the Hyfi and Hyvento hybrid cultivars [10; 26]. The grain of the hybrid cultivars was generally characterised by a higher flour yield than the population cultivars. The highest flour yield was obtained from the grain of the Hymalaya (N\({}_{1}\)) and Hypocamp (N\({}_{2}\)) hybrid cultivars. Increasing the fertilisation dosage to N\({}_{2}\) had a significant impact on increasing the flour yield in Hypocamp and Hyking hybrid cultivars and the Belissa population cultivar, by 9.5, 2.5, and 8.2%, respectively. A similar wheat flour yield without the impact of fertilisation variants was obtained by [PERSON] et al. [29], whereas [PERSON] et al. [30] indicated a significant interaction between cultivars and nitrogen fertilisation on the value of the flour yield. In this study it was shown that the Hymalaya hybrid cultivar fertilised with N\({}_{1}\) was characterised by higher flour yield than other cultivars fertilised with N\({}_{2}\) with the exception of Hypocamp. The Belissa population cultivar (N\({}_{1}\), N\({}_{2}\)) is concerned, the Hypocamp hybrid cultivar developed a grain with a lower TGW and vitreousness but with a higher bulk density, and the crude protein content in the grain of both cultivars was similar. Especially, for the Hypocamp hybrid cultivar grain with the N\({}_{2}\) dose, a higher flour yield was obtained than from the grains of the Belissa and Honda population cultivars. Among the analysed features, the lowest variability was found in bulk density and simultaneously the highest grain vitreousness.