2019, vol. 47, iss. 5, pp. 330-336
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Efficacy of fungicides in sugar leaf spot (Cercospora beticola Sacc.) control
Efikasnost fungicida u suzbijanju - prouzrokovača pegavosti lista šećerne repe (Cercospora beticola Sacc.)
aUniversity of Novi Sad, Faculty of Agriculture, Serbia bPoljoprivredna stručna služba, d.o.o., Senta
email: dragana.budakov@polj.edu.rs
Abstract
Cercospora beticola Sacc., causer of the sugar beet leaf spot is the economically most important pathogen of sugar beet. Control of this disease is carried out by applying measures within the integrated disease management, which includes good soil cultivation, pre-sowing preparation and optimal nutrition of crops to increase plant vitality. Application of fungicides is crucial for ensuring effective disease control as well as high yield or quality of sugar beet root. Today, fungicides from the chemical groups of dithiocarbamate, benzimidazole, morpholine and strobilurine are used to control sugar beet leaf spot. The efficacy of mancozeb and tebuconazole-based fungicides in the control of C. beticola with known sensitivity to these active substances was investigated during this study. Isolates were collected after the appearance of the first disease symptoms and before the application of the fungicides, while their sensitivity was tested in vitro. Obtained EC50 values, as well as the biological efficacy of applied fungicides indicated a decrease in the sensitivity of C. beticola isolates to mancozeb and tebuconazole. The highest efficacy was achieved by combining these two active substances with a different mechanism of action.
Sažetak
Cercospora beticola Sacc., prouzrokovač pegavosti lista je ekonomski najznačajniji patogen šećerne repe. Suzbijanje ovog parazita sprovodi se primenom integralnog koncepta zaštite biljaka, koji uključuje kvalitetnu obradu zemljišta, predsetvenu pripremu i optimalnu ishranu useva radi povećanja vitalnosti biljaka, dok je primena fungicida ipak odlučujuća za obezbeđivanje efikasne i sigurne zaštite kao i visokog prinosa odnosno kvaliteta korena šećerne repe. Danas se za suzbijanje pegavosti lišća šećerne repe primenjuju fungicidi iz hemijskih grupa ditiokarbamata, benzimidazola, morfolina i strobiluruna. Tokom ovog istraživanja ispitana je efikasnost fungicida na bazi mankozeba i tebukonazola u suzbijanju Cercospora beticola poznate osetljivosti prema ovim aktivnim supstancama. Osetljivost izolata je testirana in vitro prikupljanjem izolata po pojavi prvih simptoma oboljenja, a pre primene fungicida. Dobijene EC50 vrednosti, kao i ocene biološke efikasnosti fungicida ukazale su na smanjenje osetljivosti izolata Cercospora beticola prema mankozebu i tebukonazolu. Najviša biološka efikasnost ostvarena je primenom kombinacije ove dve aktivne supstance sa različitim mehanizmom delovanja.
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