Incidence of tomato ringspot nepovirus in Michigan (US)
Surveys were carried out in commercial orchards of declining 'Stanley' prune (Prunus domestica) in Michigan (US) for the prune brown line disease, associated with tomato ringspot nepovirus (EPPO A2 quarantine pest). Fifty trees per orchard were examined for symptoms of brown line and pitting-grooving symptoms beneath the bark at the graft union. Samples of tissues were taken from the graft union and tested by ELISA. In addition, vector nematodes (Xiphinema americanum) were extracted from the soil and tested for TmRSV. The results showed that there was a strong correlation between symptoms of brown line and the detection of TmRSV. Vector nematode populations correlated positively with ELISA-positive trees from southwestern Michigan but not in west central and northwestern regions of Michigan. The authors concluded that TmRSV is endemic in Michigan orchard soils.
Sources
Ramsdell, D.C.; Adler, V.A.; Kesner, C.R. (1993) Prune brown line disease occurrence in declining 'Stanley' plum orchards in Michigan and factors related to its incidence.
HortTechnology, 3 (3), 325-329.