See:
Cherry (Prunus spp.) - Nematode, Dagger
Cherry (Prunus spp.) - Nematode, Root-lesion
Note: There are many nematode problems in the Pacific Northwest including dagger and root lesion nematodes. However, there has not been any published or concentrated effort to document nematode problems in prune and plum orchards in BC, Oregon or Washington. Few samples from these orchards have come into the OSU Nematode Laboratory. It is suspected that nematodes are a problem on prune and plum that simply has not been investigated. As in cherry, ring nematodes can increase the susceptibility of Prunus trees to bacterial canker but it has not been studied in the PNW.
A strain of tomato ringspot virus (spread by the dagger nematodes Xiphinema americanum and X. rivesi) was a problem in prune orchards in western Oregon in the 70's causing a girdling and stem pitting at the graft union of infected trees.