The use of chlorothalonil for the control of benzimidazole tolerant strains of Verticillium fungicola (Preuss) Hassebr. on the cultivated mushroom

Chlorothalonil (as Daconil 2787, 75 % a.i., w.p.), applied as a drench, reduced the incidence on mushrooms of Verticillium fungicola which was tolerant to certain benzimidazole fungicides. Compared with zineb, chlorothalonil gave better disease control, required only one application and did not stain sporophores. Incorporation of chlorothalonil into the casing layer caused toxicity to the crop and depressed the yield. Where tolerance was not a problem, benomyl gave better disease control than chlorothalonil.