Effect of Ring and Pin Nematodes on the Development of Bacterial Canker and Cytospora Canker in Young French Prune Trees. Harley English, Department of Plant Pathology, University of California, Davis 95616. B. F. Lownsbery, Division of Nematology, F. J. Schick, Department of Plant Pathology, and Tom Burlando, Division of Nematology, University of California, Davis 95616. Plant Dis. 66:114-116. Accepted for publication 8 May 1981. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-114.

The ring nematode, Macroposthonia xenoplax, decreased the growth of young French prune trees on Myrobalan 29C rootstock and increased their susceptibility to both bacterial canker (Pseudomonas syringae) and Cytospora canker (Cytospora leucostoma). Under similar conditions, the pin nematode, Paratylenchus neoamblycephalus, failed to inhibit tree growth or to increase susceptibility of the trees to either canker disease. The populations of both nematodes increased substantially during the experiment.

Keyword(s):