Evaluation of the sensitivity of Leptosphaeria maculans isolates causing phoma stem canker in oilseed rape in the Czech Republic to boscalid and dimoxystrobin fungicides

Phoma stem canker, caused by Leptosphaeria spp. is generally managed with demethylation inhibitor (DMI) fungicides in the Czech Republic. However, there have been reports of resistance to DMIs L. maculans populations. Fungicide management recommends application different modes action, either as mixtures or rotation other fungicide classes. The objective, therefore, was evaluate efficacy boscalid, dimoxystrobin and a mixture boscalid dimoxystrobin, belonging succinate dehydrogenase quinone outside groups, respectively, on isolates. A total 41 285 isolates were tested using mycelial growth microtitre plate assays, respectively. EC50 values for method ranged from 0.026-0.984 µg/mL 0.097-1.653 + For range wide, between 0.053-95.59 µg/mL. assay 0.001 496-0.836 3 7.3 × 10-4-2.801 results also showed that conidia more sensitive than mycelia.