Occurrence of Thiabendazole-Resistant Strains of Penicillium italicum in Egypt. M. A. El-Goorani, Department of Plant Pathology, University of Alexandria, Alexandria. H. M. El-Kasheir, Department of Plant Pathology, University of Alexandria, Alexandria, M. T. Kabeel, Department of Horticulture, University of Cairo, Cairo, and Alia Shoeib, Department of Plant Pathology, University of Alexandria, Alexandria, Egypt. Plant Dis. 67:618-619. Accepted for publication 15 November 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-618.

Blue mold (Penicillium italicum) was a more prevalent decay than green mold (P. digitatum) on Valencia oranges treated with thiabendazole (TBZ). Some blue mold isolates from decayed fruits were resistant to concentrations of TBZ at least 2,000 times greater than the minimal dose required to inhibit the sensitive isolates. The TBZ-resistant isolates were as virulent as the TBZ-sensitive isolates.