Resistenz des Bitterfäule-Erregers Neofabraea perennans gegen Thiophanate-methyl: Konidienkeimung vs. Hyphenwachstum

Isolates of Neofabraea perennans were grouped into three categories according to their pattern of resistance against thiophanate-methyl. ED₅₀ values were 0.067?±?0.003?ppm (mycelial growth) or 0.202?±?0.028?ppm (conidial germination) for strains with baseline sensitivity, and 1.35?±?0.30?ppm or 9.75?±?3.18?ppm (respectively) for strains with partial resistance against thiophanate-methyl. Highly resistant strains were not inhibited even at 400?ppm thiophanate-methyl. The mycelial growth assay is recommended for further research on benzimidazole resistance in bitter-rot fungi because of its enhanced sensitivity as well as simple and reproducible evaluation. A detailed protocol for this assay method is given.