Impact of nitrogen fertilisation on the technological value of sugar beet cultivar roots

The present field experiment and lab investigations analysed the effect of nitrogen fertilisation at the rates of 0, 80, 160 and 240 kgˇha-1 on the technological root value of the following cultivars ‘Action’, ‘Amelia’, ‘Atair’, ‘Cordelia’, ‘Dojana’, ‘Evita’, ‘Fontana’, ‘Gala’, ‘Hanna’, ‘Jupiter’, ‘Nilla’, ‘PN Mono 4’ ‘Sofie’ and ‘Sonja’. 80 and 160 kgˇha-1 of N resulted in a significant increase in the single root weight, root yield and the biological sugar yield. Technological sugar yield justified only the application of 80 kgˇha-1 of N. The increase in the technological sugar yield at 160 kgˇha-1 of N was insignificant, while an increase in N rate up to 240 kgˇha-1 made the yield correspond to that obtained for 80 kgˇha-1 of N. With rates increasing by further 80 kgˇha-1 of N, there were observed increases in the contents of alpha-amino N, sodium and potassium and decreased content of sucrose.