VIEW ARTICLE

Fungitoxic Spectrum of Benzimidazole Compounds. L. V. Edgington, Professor, Department of Botany, University of Guelph, Guelph, Ontario, Canada; K. L. Khew(2), and G. L. Barron(3). (2)(3)Graduate student, and Professor, respectively, Department of Botany, University of Guelph, Guelph, Ontario, Canada. Phytopathology 61:42-44. Accepted for publication 5 August 1970. DOI: 10.1094/Phyto-61-42.

Fungitoxicity of three benzimidazole compounds was examined in vitro. Benomyl [methyl 1-(butyl-carbamoyl)-2-benzimidazolecarbamate] was extremely toxic to a wide spectrum of fungi, but was nontoxic to certain taxonomic groups. Among the Deuteromycetes, the sensitive groups were Phialosporae, Arthrosporae, Sympodulosporae, and Aleuriosporae, while only some genera of Annellosporae and Blastosporae were sensitive; all Porosporae were insensitive. Within the Blastosporae, only those genera having perfect stages in the Sclerotiniaceae of the Euascomycetes were sensitive to benomyl, while the yeast, Candida, with a perfect stage in the Hemiasco-mycetes was resistant. Within the Porosporae, benomyl was nontoxic to such important pathogens as Alternaria, Drechslera, Bipolaris, Stemphylium, and Curvularia. A comparison of benomyl with thiabendazole and Bay 33172 [2-(2-furyl)-benzimidazole] revealed an identical pattern of selective fungitoxicity. Consequently, the selective toxicity of all three compounds depends on the benzimidazole portion of the molecule.