Phomopsis Canker and Dieback of Elaeagnus angustifolia. A. L. Morehart, Associate Professor of Plant Pathology, Plant Science Department, University of Delaware, Newark, 19711. R. B. Carroll, and M. Stuart, Associate Professors of Plant Pathology and Graduate Student, respectively, Plant Science Department, University of Delaware, Newark, 19711. Plant Dis. 64:66-69. Accepted for publication 7 March 1979. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-66.

The pathogenicity of Phomopsis elaeagni was assessed on Russian-olive trees wounded at three sites and inoculated by four methods. Disease (wilt) was induced nearly equally in 2-yr-old trees inoculated by wounding the secondary phloem and cork, secondary xylem, and roots. The fungus moved into the root system and up the stem after either superficial or deep wounding in trees 60 cm high. The same pattern was evident in trees 40 cm high, except that greater upward movement occurred in 60-cm trees inoculated in the roots. Deep wounding produced the most severe disease symptoms in cuttings. Of eight Phomopsis spp. tested, only P. elaeagni produced disease in Russian-olive cuttings. Extensive culturing from soil on which diseased Russian-olive trees grew failed to yield P. elaeagni.

Keyword(s): Diaporthe, oleaster.