Occurrence of Fusarium head blight of winter wheat (Fusarium culmorum - DON chemotype) in dependence on fungicidal protection programs.

摘要

Winter wheat ear inoculation with suspension of conidia of F. culmorum representing deoxynivalenol (DON) chemotype, confirmed with PCR assay, was conducted during anthesis. Plants on the control plots showed Fusarium head blight (FHB) symptoms on 94.0% of the ears, while the mean disease index was 43.5%. All the fungicides, applied twice (at BBCH phase 29-32 and 49-55), significantly reduced the FHB intensity. The best control efficacy (over 70%) against FHB as well as the highest yield was obtained after the application of spiroxamine (300 l/ha)+prothioconazole (160 l/ha) at growth phase 29-32, and prothioconazole (100 l/ha)+fluoxastrobin (100 l/ha) at phase 49-55 (the yield was 166.5% of the control) or tebuconazole (125 l/ha), prothioconazole (125 l/ha) (165.8%). All other protection programmes resulted in higher yield (117.1-135.4% of the control). A clear relation was observed between the disease intensity and DON concentration.