engleski

Sugar Beet Quality in Dependence on the Effectiveness of Fungicides and Genotype on Cercospora beticola Sacc.

Sugar beet is one of two the most important industrial cultures for sugar production. A large number of factors have an impact on the achieved results in the sugar beet production, whereby the most important one is the appearance and development of leaf disease caused by C. beticola Sacc. In the area where sugar beet is grown, the damage by this fungal plant patogen is large. It depends on the cropping practices, abiotic factors, quality and quantity of the composition of microorganisms in the soil and the disease control measures. Application of tolerant hybrids has become a rule in the areas where it is cultivated sugar beet. By breeding were obtained tolerant hybrids against this pathogen, on the other side, this tolerance did not influence the yield reduction, as it was the case with the first obtained tolerant hybrids to fungus C. beticola Sacc. Application of fungicides is necessary for sensitive and tolerant sugar beet hybrids. The efficiency of the treatment depends on the application time, number of applications and the choice of fungicide - contact or sistemic. Furthermore, it is extremely important to choose the right active substance of fungicide, which means do not use twice the same active substance, or combine two or more active substances in order to avoid the development of resistance. For these reasons, the aim of this study was to determine root yield and root quality of sugar beet under different climate and soil conditions in dependence of fungicide efficiency and the tolerance to fungus Cercospora beticola Sacc. of the studied hybrids. Research of production values 8 hybrids were 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 since 2010. until 2012. Hybrids involved in the experiments are unequal tolerance to the fungus C. beticola and they are ownership of four selection houses that sell sugar beet seed in the Republic of Croatia. Weather conditions during the research were significantly different. The first was with increased, while the remaining two with small amounts of rainfall compared to the long term average. In all three years monthly air temperatures during the growing period were elevated, especially 2012th year. The obtained results show strong dependence of yield and quality of the roots of through vegetation of conservation leaf, hybrids and year. Because of damage to the leaves, on variants where no treatment was carried out in relation to the well-preserved variant with three treatments, root yield was reduced 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%). Damages due to omitted fungicide application were highly significant for all hybrids, and the repeated use of fungicides to combat C. beticola Sacc., it is still mandatory and highly cost- effective measures in sugar beet production. On average of research by highest root yields hybrids were Boomerang, Colonia, KWS and Sandor. The highest sugar content were found in Colonia KWS, Asketa and Boomerang. Content of sugar in molasses best hybrid was Colonia KWS. By pure sugar yield significantly better than the others were hybrids Colonia KWS and Boomerang.

sugar beets ; hybrids ; Cercospora beticola Sacc. ; yield ; root quality

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