Control of Nectria cinnabarina Cankers on Honey Locust. P. J. Bedker, Graduate Research Assistant, Department of Plant Pathology, University of Minnesota, St. Paul 55108. R. A. Blanchette, Assistant Professor, Department of Plant Pathology, University of Minnesota, St. Paul 55108. Plant Dis. 68:227-230. Accepted for publication 7 September 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-227.

Four cultivars of thornless honey locust were inoculated with Nectria cinnabarina, a canker-causing pathogen of honey locust in Minnesota, to determine their relative susceptibility. The cultivars Sunburst, Skyline, and Imperial were about equal in susceptibility to infection, and Thornless was more resistant. Concentrations of benomyl exceeding 1 μg/ml totally inhibited growth of N. cinnabarina in vitro. Five-year-old honey locust trees were wounded and then inoculated with N. cinnabarina after various intervals. Two concentrations of benomyl were tested for efficacy in preventing canker formation. Wounds inoculated 2 hr or 1 day after wounding developed cankers. Wounds inoculated 1 wk or more after wounding were not significantly larger (P>0.05) than the uninoculated wounds. Wounds sprayed with a solution of 10 μg/ml benomyl and subsequently inoculated with N. cinnabarina were not significantly different (P>0.05) from unsprayed wounds. However, wounds sprayed with a concentration of 100 μg/ml benomyl and inoculated 1 day after wounding were significantly smaller (P<0.05) than unsprayed, inoculated wounds.