Yield and Grain Quality of Hulless Spring Barley in Field Trials Under Different Nitrogen Management Conditions

The aim of the study was to evaluate the yield and grain quality (1000 kernel weight, test weight, crude protein, starch, β-glucans, total phenolic content, antiradical scavenging activity and α-tocopherol content) variation of three hulless spring barley (Hordeum vulgare L.) genotypes under different levels of N, in relation to weather characteristics. The field experiments were carried out at the State Stende Cereal Breeding Institute. Three hulless barley genotypes ‘Kornelija’; ‘ST 1165’; ST 1185’ were studied during two years (2011 and 2012) using three levels of nitrogen (N80; N80+40; N80+80) by split application at the end of the tillering stage. The effects of genotype, N treatment and genotype by N treatment interaction contribute the variation in yield and grain quality traits for hulless barley genotypes. There were considerable differences between crop years in response of hulless genotypes to top-dressing N, with significantly (P < 0.05) higher grain yield, 1000 kernel weight, test weight, starch and β-glucans in the growing season of 2012, when rainfall was optimal at the tillering and stem-elongation growth stages. In 2012, a significant (P < 0.05) response to top-dressing N was recorded for grain yield and 1000 kernel weight (at rate N120), crude protein, starch and β-glucans (at rate N160). The maximum values of total phenolic content, antiradical scavenging activity (in 2011) and -tocopherol content (in 2012) were obtained with application of 160 kg N ha^-1. Hulless line ‘1185’ gave the highest grain yield, starch, α-tocopherol content and radical scavenging activity, but variety ‘Kornelija’ formed significantly higher TKW, crude protein and β-glucans content.