Abstract

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During the period of 2013-2015, in the proving grounds of the Agricultural Institute- Shumen was performed an assessment for the agent causing cercosporosis – Cercospora beticola Sacardo from 19 selection materials of sugar beet. The assessment is made under natural infectious background, with importing of the leaf fertilizer „Chumustin” (1000ml/ha), as well as without it. For the aims of the examination is performed proving test on the block method scheme, in four successions. The recordings are made based on point scales unified by the Agricultural Institute. The infection index of the cercosporosis is determined and the sorts’ reaction of the tested materials was compared, in order for the materials to be assessed with the stability methodic, which is standard for the country. It was determined that the infection index of the cercosporosis Cercospora beticola Sacardo for the sugar beet depends mostly on the stability of the plants and to a lesser extent on the external conditions; the tested selection materials are averagely sensitive and averagely stable; the import of the leaf fertilizer „Chumustin”, in dose 1000ml/ha, under favourable conditions for the development of the cercosporosis, does not affect the infection index values.

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