Genetic Variation in Grain Yield and Quality Traits of Spring Malting Barley

Cultivation of malting barley is particularly challenging as the requirements of growers, for high yield, and that of the brewing industry, seeking a specific quality criteria, must be met simultaneously. Furthermore, significant genotypic and environmental variations in grain yield and quality properties may occur. To investigate the relationships between grain yield and quality parameters of spring malting barley, a 2-year experiment was carried out in order to characterise the genotypic and year effects on grain yield, quality properties, and yield components of 23 high-yielding varieties of spring malting barley under optimal nitrogen (N) fertilisation. Compared to the grain quality properties of the grain protein content and the grain retention fraction of grain size >2.5 mm, less genotypic and environmental variation in grain yield was observed. Grain yield was closely related to spikes per m2, suggesting the importance of tiller formation and establishment as a decisive factor influencing malting barley yields. A major interactive effect of genotypes and year on grain size was observed. Regarding weather effects, the global radiation intensity during the post-anthesis phase was the major factor affecting the final grain size in this study. Grain protein content was primarily dependent on the year effect, suggesting that optimal N fertilisation levels must vary between years to ensure the correct protein content required for the needs of the brewing industry is met. Therefore, we recommend further development strategies addressing N fertilisation and soil N mineralisation to optimise the production of spring malting barley.