SUGAR BEET QUALITY IN DEPENDENCE ON VARIETY AND EFFECTIVENESS OF FUNGICIDES ON CERCOSPORA BETICOLA SACC

Between the years 2010 and 2012 research on production values of 8 varieties was performed on eutric brown soil in eastern Croatia in the conditions of natural infection with a pathogenic fungus Cercospora beticola Sacc. with and without fungicide application. Varieties involved in the experiments had unequal tolerance to the fungus C. beticola. Weather conditions during the research differed significantly in the individual years. Compared to the long term average, the overall rainfall was high in the first year and low in the other two years. Monthly air temperatures during the growing period were elevated in all three years, especially in 2012. The obtained results show strong dependence of yield and quality of the roots on leaf conservation during the vegetation period, on variety and on year. Due to substantial damage to the leaves in variants with no treatment in relation to the well-preserved variant with three treatments, root yield in the latter increased by an average of 15.92 t ha(-1) (20.64%), sugar content 1.61% (rel. 10.37%) and sugar yield for 3.07 t ha(-1) (30.67%).