RESULTS OF SUGAR BEET PRODUCTION DEPENDING ON THE HYBRIDS SELECTION AND THE NUMBER OF FUNGICIDE APPLICATION

Abstract

The study of the production values of 10 sugar beet hybrids was conducted on chernozem soil type in Eastern Croatia (Tovarniklocation). The used treatments with and without fungicides application were investigated in 2013 and 2014. Sugar beet hybrids used in the study originate from three market-leading sugar beet seed companies in Croatia, whose varieties provide disease tolerance to C. beticola. The years of the study were quite warm with higher mean monthly air temperature (°C) and increased amount of rainfall, as compared to the long-term mean. In the second year of the study, due to increased amount of rainfall (mm) in July and August, as well as the total loss ofstrobilurin efficiency and low effectiveness ofthe cyproconazole treatment, the destruction ofthe leaves by C. beticola Sacc. was significantly higher. The results of the study showed a huge coherence of sugar beet yield and quality with leaf conservation through the vegetation (the number of treatment), and with the hybrids. Due to leaves destruction on control treatments, as compared to fungicide application three times, the sugar beet root yield was reduced on the average by 9.79 t ha'1 (10.03%), sugar content by 0.69% (rel. 4.89%) and sugar yield by 2.041 ha1 (17.04%). On the other hand, three fungicide applications increased the root yield by 4.881 ha1 (5.26%), sugar content by 0.52% and sugar yield by 0.99 t ha1 (9.01%) as compared to one fungicide application. All sugar beet hybrids of the study were strongly negatively affected the control treatment, indicating repeated fungicide application against C. beticola as a regular agricultural practices. On the average, for all variations of fungicides applications, the sugar beet hybrid Jadranka had significantly higher root yield in comparison with other hybrids included in the study. Moreover, the highest sugar content achieved Sandor, Marianka and Kundera. Significantly higher sugar yield had a hybrid Jadranka.

Keywords

• sugar beet
• hybrid
• Cercospora beticola Sacc
• fungicides
• yield
• root quality