Resistance to benzimidazole fungicide in blue mould of citrus in Queensland

Abstract

Two of seven isolates of Penicillium italicum Wehmer (blue mould) from different consignments of citrus were resistant in vitro to thiabendazole, benomyl, thiophanate-methyl and carbendazim. The application of thiabendazole and benomyl to Late Valencia oranges inoculated with the resistant isolates failed to prevent the development of blue mould. No resistance was found in seven isolates of P. digitatum Sacc. (green mould).