TESTOVÁNÍ ÚČINNOSTI VYBRANÝCH FUNGICIDŮ PROTI DIPLOCARPON CORONARIAE V IN VITRO PODMÍNKÁCH [IN VITRO EVALUATION OF EFFICACY OF SELECTED FUNGICIDES AGAINST DIPLOCARPON CORONARIAE ]

Abstract

Apple leaf blotch, a disease that is caused by the fungus Diplocarpon coronariae (also known as Marssonina coronaria) is a serious apple tree pathogen in areas with optimal conditions for its development. The fungus mainly attacks the leaves of apple trees, resulting in defoliation, which indirectly affects fruit size and color, yield and development of the apple tree shoots. In this experiment, the effectiveness of selected fungicides was tested (Sercadis – active ingredient fluxapyroxad, Belanty – active ingredient mefentrifluconazole, Topas 100 EC – active ingredient penconazole, Delan 700 WDG – active ingredient dithianon, Bellis – active ingredient boscalid and pyraclostrobin, Geoxe 50 WG – active ingredient fludioxonil, Kumulus WG – active ingredient sulphur, Cyflamid 50 EW – active ingredient cyflufenamid) for inhibiting the growth of D. coronariae using the pathogen colony cultivation method on PDA medium with addition of the fungicide. The best results were achieved by fungicides Topas 100 EC, Bellis, Sercadis and Belanty with the effectiveness of 98–100 %. Lower growth reduction was shown by Delan 700 WDG with an efficiency of 68 %. Kumulus WG, Geoxe 50 WG and Cyflamid 50 EW limited the growth of the pathogen with a reduced efficiency of 37, 22 and 15 %, respectively. There was no effect of these fungicides on growth reduction of some fungal strains.

Keywords

• diplocarpon mali
• marssonina leaf and fruit blotch
• fungicides
• apple tree
• marssonina coronaria