Disease Note

Cankers on Russian Olive in Windbreaks in North Dakota and South Dakota. J. M. Krupinsky, USDA-ARS, Northern Great Plains Research Laboratory, Mandan, ND 58554. Plant Dis. 70:981. Accepted for publication 26 May 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-981f.

From 1978 through 1982, 434 cankers were randomly collected from windbreaks of Russian olive (Elaeagnus angustifolia L.) in 28 counties in North Dakota and in six in South Dakota. Most cankers were collected from recently girdled branches from tree plantings. Wood chips from each of the cankers were cultured to determine fungi present. Tubercularia ulmea Carter was isolated from 29% of the 434 cankers cultured and Phomopsis arnoldiae Sutton (syn. Phomopsis elaeagni (Carter & Sacamano) Arnold & Carter), from 3%. The collection of T. ulmea in 26 of the 34 counties sampled documents the presence of the fungus on Russian olive throughout North Dakota and northeastern South Dakota. P. arnoldiae has not been previously reported in the Dakotas. Of nine species of fungi tested in a series of glasshouse and field inoculations, only these two fungi and a Diplodia sp. were determined to be pathogenic to Russian olive. Inoculation procedures were similar to those described previously (1). In the field, 45% of 66 branches inoculated with 11 isolates of T. ulmea had cankers that caused flagging symptoms. This is the first report of the pathogenicity of T. ulmea to Russian olive.