The potato production industry has been severely impacted by a wilt disease; Potato Early Die (PED) complex (Verticillium dahliae Kleb. and Pratylenchus penetrans) and a storage disease; silver scurf (Helminthosporium solani). Experimental field trials were conducted in 2018 and 2020 to evaluate chemical management programs for PED. Vydate C-LV treatment reduced Pratylenchus penetrans populations in soil. In vitro studies were established to evaluate three methods to estimate in vitro sensitivity of Helminthosporium solani to three classes of fungicides. Sensitivity expressed in mg/L was defined as the effective fungicide concentration at which 50% of the fungal growth or spore germination is inhibited (EC50). Helminthosporium solani isolates were most sensitive to pydiflumetofen, difenoconazole and benzovindiflupyr. The relative germination method is recommended for screening succinate dehydrogenase inhibitors. The relative growth method using a spiral gradient dilution may also be used but is recommended for screening demethylation inhibitors and phenylpyrrole fungicides due to their mode of action.
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